Stomach cancer, also known as gastric cancer, is a

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

that develops from the lining of the stomach. Most cases of stomach cancers are gastric

carcinomas Carcinoma is a malignancy that develops from epithelial cells. Specifically, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that arises from cells originating in the endodermal, mesoder ...

, which can be divided into a number of subtypes, including gastric

adenocarcinomas Adenocarcinoma (; plural adenocarcinomas or adenocarcinomata ) (AC) is a type of cancerous tumor that can occur in several parts of the body. It is defined as neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or ...

Lymphomas Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enla ...

and mesenchymal tumors may also develop in the stomach. Early symptoms may include

heartburn Heartburn, also known as pyrosis, cardialgia or acid indigestion, is a burning sensation in the central chest or upper central abdomen. Heartburn is usually due to regurgitation of gastric acid (gastric reflux) into the esophagus. It is the m ...

, upper abdominal pain,

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

, and

loss of appetite Anorexia is a medical term for a loss of appetite. While the term in non-scientific publications is often used interchangeably with anorexia nervosa, many possible causes exist for a loss of appetite, some of which may be harmless, while others i ...

. Later signs and symptoms may include

weight loss Weight loss, in the context of medicine, health, or physical fitness, refers to a reduction of the total body mass, by a mean loss of fluid, body fat (adipose tissue), or lean mass (namely bone mineral deposits, muscle, tendon, and other conn ...

, yellowing of the skin and whites of the eyes,

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the Human nose, nose. Vomiting can be the result of ailments like Food-poisoning, foo ...

difficulty swallowing Dysphagia is difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right. It may be a sensation that suggests difficulty in the passage of solids or liqui ...

, and

blood in the stool Blood in stool looks different depending on how early it enters the digestive tract—and thus how much digestive action it has been exposed to—and how much there is. The term can refer either to melena, with a black appearance, typically orig ...

, among others. The cancer may

spread Spread may refer to: Places * Spread, West Virginia Arts, entertainment, and media * ''Spread'' (film), a 2009 film. * ''$pread'', a quarterly magazine by and for sex workers * "Spread", a song by OutKast from their 2003 album ''Speakerboxxx/T ...

from the stomach to other parts of the body, particularly the

liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

lungs The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of th ...

bone A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...

s, lining of the abdomen, and

lymph node A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that inclu ...

s. The most common cause is infection by the

bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

Helicobacter pylori ''Helicobacter pylori'', previously known as ''Campylobacter pylori'', is a gram-negative, microaerophilic, spiral (helical) bacterium usually found in the stomach. Its helical shape (from which the genus name, helicobacter, derives) is though ...

'', which accounts for more than 60% of cases. Certain types of ''H. pylori'' have greater risks than others. Smoking, dietary factors such as pickled vegetables and

obesity Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's we ...

are other risk factors. About 10% of cases run in families, and between 1% and 3% of cases are due to

genetic syndromes A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek σύνδρομον, meaning "concurrence". When a syndrome is paired ...

inherited from a person's parents such as

hereditary diffuse gastric cancer Hereditary diffuse gastric cancer (HDGC) is an inherited genetic syndrome most often caused by an inactivating mutation in the E-cadherin gene (CDH1) located on chromosome 16. Individuals who inherit an inactive copy of the CDH1 gene are at signi ...

. Most of the time, stomach cancer develops in stages over years. Diagnosis is usually by

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a diseas ...

done during

endoscopy An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...

. This is followed by

medical imaging Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to rev ...

to determine if the disease has spread to other parts of the body.

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

and

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...

, two countries that have high rates of the disease, screen for stomach cancer. A

Mediterranean diet The Mediterranean diet is a diet inspired by the eating habits of people who live near the Mediterranean Sea. When initially formulated in the 1960s, it drew on the cuisines of Greece, Italy, France and Spain. In decades since, it has also incor ...

lowers the risk of stomach cancer, as does the stopping of smoking. Tentative evidence indicates that treating ''H. pylori'' decreases the future risk. If stomach cancer is treated early, it can be cured. Treatments may include some combination of surgery,

chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...

radiation therapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...

, and

targeted therapy Targeted therapy or molecularly targeted therapy is one of the major modalities of medical treatment (pharmacotherapy) for cancer, others being hormonal therapy and cytotoxic chemotherapy. As a form of molecular medicine, targeted therapy blocks ...

. For certain subtypes of gastric cancer,

cancer immunotherapy Cancer immunotherapy (sometimes called immuno-oncology) is the stimulation of the immune system to treat cancer, improving on the immune system's natural ability to fight the disease. It is an application of the fundamental research of cancer im ...

is an option as well. If treated late,

palliative care Palliative care (derived from the Latin root , or 'to cloak') is an interdisciplinary medical caregiving approach aimed at optimizing quality of life and mitigating suffering among people with serious, complex, and often terminal illnesses. Wit ...

may be advised. Some types of lymphoma can be cured by eliminating ''H. pylori''. Outcomes are often poor, with a less than 10%

five-year survival rate The five-year survival rate is a type of survival rate for estimating the prognosis of a particular disease, normally calculated from the point of diagnosis. Lead time bias from earlier diagnosis can affect interpretation of the five-year surviva ...

in the Western world for advanced cases. This is largely because most people with the condition present with advanced disease. In the United States, five-year survival is 31.5%, while in South Korea it is over 65% and Japan over 70%, partly due to screening efforts. Globally, stomach cancer is the fifth-leading type of cancer and the third-leading cause of death from cancer, making up 7% of cases and 9% of deaths. In 2018, it newly occurred in 1.03 million people and caused 783,000 deaths. Before the 1930s, in much of the world, including most

Western Western may refer to: Places *Western, Nebraska, a village in the US *Western, New York, a town in the US *Western Creek, Tasmania, a locality in Australia *Western Junction, Tasmania, a locality in Australia *Western world, countries that id ...

developed countries, it was the most common cause of death from cancer. Rates of death have been decreasing in many areas of the world since then. This is believed to be due to the eating of less salted and pickled foods as a result of the development of

refrigeration The term refrigeration refers to the process of removing heat from an enclosed space or substance for the purpose of lowering the temperature.International Dictionary of Refrigeration, http://dictionary.iifiir.org/search.phpASHRAE Terminology, ht ...

as a method of storing food. Stomach cancer occurs most commonly in

East Asia East Asia is the eastern region of Asia, which is defined in both geographical and ethno-cultural terms. The modern states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. China, North Korea, South Korea and ...

and

Eastern Europe Eastern Europe is a subregion of the Europe, European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. The vast majority of the region is covered by Russ ...

. It occurs twice as often in males as in females.

Signs and symptoms

Stomach cancer is often either

asymptomatic In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered asy ...

(producing no noticeable symptoms) or it may cause only

nonspecific symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

(which may also be present in other related or unrelated disorders) in its early stages. By the time symptoms are recognized, the cancer has often reached an advanced stage (see below) and may have metastasized (spread to other, perhaps distant, parts of the body), which is one of the main reasons for its relatively poor prognosis. Stomach cancer can cause the following signs and symptoms: Unexplained nausea, vomiting, diarrhoea and constipation. Patients also can experience unexplained weight loss. Early cancers may be associated with

indigestion Indigestion, also known as dyspepsia or upset stomach, is a condition of impaired digestion. Symptoms may include upper abdominal fullness, heartburn, nausea, belching, or upper abdominal pain. People may also experience feeling full earlier t ...

or a burning sensation (

). However, fewer than one in every 50 people referred for endoscopy due to indigestion has cancer.

Abdominal discomfort Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues. Common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome. About 15% of people have a more ...

and

, especially for meat, can occur. Gastric cancers that have enlarged and invaded normal tissue can cause

weakness Weakness is a symptom of a number of different conditions. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, i ...

, fatigue,

bloating Abdominal bloating (or simply bloating) is a short-term disease that affects the gastrointestinal tract. Bloating is generally characterized by an excess buildup of gas, air or fluids in the stomach. A person may have feelings of tightness, press ...

of the stomach after meals,

abdominal pain Abdominal pain, also known as a stomach ache, is a symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than ...

in the upper abdomen,

and occasional

. Further enlargement may cause

bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...

with

vomiting blood Hematemesis is the vomiting of blood. It is always an important sign. It can be confused with hemoptysis (coughing up blood) or epistaxis (nosebleed), which are more common. The source is generally the upper gastrointestinal tract, typically abo ...

or having

, the latter apparent as black discolouration ( melena) and sometimes leading to

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, th ...

Dysphagia Dysphagia is difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, in some contexts it is classified as a disease#Terminology, condition in its own right. It may be a sensation that suggests difficulty in the passag ...

suggests a tumour in the cardia or extension of the gastric tumour into the

esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the ...

. These can be symptoms of other problems such as a stomach virus, gastric ulcer, or

tropical sprue Tropical sprue is a malabsorption disease commonly found in tropical regions, marked with abnormal flattening of the villi and inflammation of the lining of the small intestine. It differs significantly from coeliac sprue. It appears to be a more ...

Risk factors

Gastric cancer can occur as a result of many factors. It occurs twice as commonly in males as females.

Estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...

may protect women against the development of this form of cancer.

Infections

'' infection is an essential risk factor in 65–80% of gastric cancers, but only 2% of people with ''H. pylori'' infections develop stomach cancer. The mechanism by which ''H. pylori'' induces stomach cancer potentially involves chronic inflammation, or the action of ''H. pylori'' virulence factors such as

CagA ''Helicobacter pylori'' virulence factor CagA (cytotoxin-associated gene A) is a 120–145kDa protein encoded on the 40kb ''cag'' pathogenicity island (PAI). ''H. pylori'' strains can be divided into CagA positive or negative strains. Approximately ...

. It was estimated that

Epstein–Barr virus The Epstein–Barr virus (EBV), formally called ''Human gammaherpesvirus 4'', is one of the nine known human herpesvirus types in the herpes family, and is one of the most common viruses in humans. EBV is a double-stranded DNA virus. It is b ...

is responsible for 84,000 cases per year.

AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual m ...

is also associated with elevated risk.

Smoking

Smoking increases the risk of developing gastric cancer significantly, from 40% increased risk for current smokers to 82% increase for heavy smokers. Gastric cancers due to smoking mostly occur in the upper part of the stomach near the esophagus.

Alcohol

Some studies show increased risk with alcohol consumption as well.

Diet

Sequence of 123-iodide total body human scintiscans

Dietary factors are not proven causes, and the association between stomach cancer and various foods and beverages is weak. Some foods including smoked foods, salt and salt-rich foods, red meat,

processed meat Processed meat is considered to be any meat which has been modified in order to either improve its taste or to extend its shelf life. Methods of meat processing include salting, curing, fermentation, smoking, and/or the addition of chemical pre ...

, pickled vegetables, and

bracken Bracken (''Pteridium'') is a genus of large, coarse ferns in the family Dennstaedtiaceae. Ferns (Pteridophyta) are vascular plants that have alternating generations, large plants that produce spores and small plants that produce sex cells (eggs ...

s are

associated Associated may refer to: *Associated, former name of Avon, Contra Costa County, California * Associated Hebrew Schools of Toronto, a school in Canada *Associated Newspapers, former name of DMG Media, a British publishing company See also *Associati ...

with a higher risk of stomach cancer. Nitrates and nitrites in cured meats can be converted by certain bacteria, including ''H. pylori'', into compounds that have been found to cause stomach cancer in animals. Fresh fruit and vegetable intake, citrus fruit intake, and

antioxidant Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...

intake are associated with a lower risk of stomach cancer. A Mediterranean diet is associated with lower rates of stomach cancer, as is regular

aspirin Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat inc ...

use. Obesity is a physical risk factor that has been found to increase the risk of gastric adenocarcinoma by contributing to the development of

gastroesophageal reflux disease Gastroesophageal reflux disease (GERD) or gastro-oesophageal reflux disease (GORD) is one of the upper gastrointestinal chronic diseases where stomach content persistently and regularly flows up into the esophagus, resulting in symptoms and/ ...

(GERD). The exact mechanism by which obesity causes GERD is not completely known. Studies hypothesize that increased dietary fat leading to increased pressure on the stomach and the lower esophageal sphincter, due to excess adipose tissue, could play a role, yet no statistically significant data have been collected. However, the risk of gastric cardia adenocarcinoma, with GERD present, has been found to increase more than 2 times for an obese person. There is a correlation between

iodine deficiency Iodine deficiency is a lack of the trace element iodine, an essential nutrient in the diet. It may result in metabolic problems such as goiter, sometimes as an endemic goiter as well as congenital iodine deficiency syndrome due to untreated cong ...

and gastric cancer.

Genetics

About 10% of cases run in families, and between 1 and 3% of cases are due to genetic syndromes inherited from a person's parents such as

. A genetic risk factor for gastric cancer is a genetic defect of the ''CDH1'' gene known as

(HDGC). The ''CDH1'' gene, which codes for E-cadherin, lies on the 16th chromosome. When the gene experiences a particular mutation, gastric cancer develops through a mechanism that is not fully understood. This mutation is considered autosomal dominant, meaning that half of a carrier's children will likely experience the same mutation. Diagnosis of hereditary diffuse gastric cancer usually takes place when at least two cases involving a family member, such as a parent or grandparent, are diagnosed, with at least one diagnosed before the age of 50. The diagnosis can also be made if at least three cases occur in the family, in which case age is not considered. The

International Cancer Genome Consortium The International Cancer Genome Consortium (ICGC) is a voluntary scientific organization that provides a forum for collaboration among the world's leading cancer and genomic researchers. The ICGC was launched in 2008 to coordinate large-scale can ...

is leading efforts to identify genomic changes involved in stomach cancer. A very small percentage of diffuse-type gastric cancers (see Histopathology below) arise from an inherited abnormal '' CDH1''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

. Genetic testing and treatment options are available for families at risk.

Other

Other risk factors include

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...

pernicious anemia Pernicious anemia is a type of vitamin B12 deficiency anemia, a disease in which not enough red blood cells are produced due to the malabsorption of vitamin B12. Malabsorption in pernicious anemia results from the lack or loss of intrinsic fa ...

, chronic atrophic gastritis, Menetrier's disease (hyperplastic, hypersecretory gastropathy), and

intestinal metaplasia Intestinal metaplasia is the transformation (metaplasia) of epithelium (usually of the stomach or the esophagus) into a type of epithelium resembling that found in the intestine. In the esophagus, this is called Barrett's esophagus. Chronic inflam ...

. In addition,

Foxp3 FOXP3 ( forkhead box P3), also known as scurfin, is a protein involved in immune system responses. A member of the FOX protein family, FOXP3 appears to function as a master regulator of the regulatory pathway in the development and function of ...

polymorphism (rs3761548) might contribute to

gastric cancer Stomach cancer, also known as gastric cancer, is a cancer that develops from the lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a number of subtypes, including gastric adenocarcinomas. Lymph ...

development through influencing

Treg The regulatory T cells (Tregs or Treg cells), formerly known as suppressor T cells, are a subpopulation of T cells that modulate the immune system, maintain tolerance to self-antigens, and prevent autoimmune disease. Treg cells are immunosu ...

cell activity.

Diagnosis

To find the cause of symptoms, the doctor asks about the patient's medical history, does a physical examination, and may order laboratory studies. The patient may also have one or all of these exams: * Gastroscopic exam is the diagnostic method of choice. This involves insertion of a fibre optic camera into the stomach to visualise it. *

Upper GI series An upper gastrointestinal series, also called a barium swallow, barium study, or barium meal, is a series of radiographs used to examine the gastrointestinal tract for abnormalities. A contrast medium, usually a radiocontrast agent such as bari ...

(may be called barium roentgenogram) * Computed tomography or CT scanning of the abdomen may reveal gastric cancer. It is more useful to determine invasion into adjacent tissues or the presence of spread to local lymph nodes. Wall thickening of more than 1 cm that is focal, eccentric, and enhancing favours malignancy. In 2013, Chinese and Israeli scientists reported a successful

pilot study A pilot study, pilot project, pilot test, or pilot experiment is a small-scale preliminary study conducted to evaluate feasibility, duration, cost, adverse events, and improve upon the study design prior to performance of a full-scale research p ...

of a

breathalyzer A breathalyzer or breathalyser (a portmanteau of ''breath'' and ''analyzer/analyser'') is a device for estimating blood alcohol content (BAC), or to detect viruses or diseases from a breath sample. The name is a genericized trademark of the Br ...

-style breath test intended to diagnose stomach cancer by analyzing exhaled chemicals without the need for an intrusive

. A larger-scale

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...

of this technology was completed in 2014. Abnormal tissue seen in a gastroscope examination is

biopsied A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a disea ...

by the

surgeon In modern medicine, a surgeon is a medical professional who performs surgery. Although there are different traditions in different times and places, a modern surgeon usually is also a licensed physician or received the same medical training as ...

gastroenterologist Gastroenterology (from the Greek gastḗr- “belly”, -énteron “intestine”, and -logía "study of") is the branch of medicine focused on the digestive system and its disorders. The digestive system consists of the gastrointestinal tract, ...

. This tissue is then sent to a

pathologist Pathology is the study of the causal, causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when us ...

for

histological Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...

examination under a microscope to check for the presence of cancerous cells. A biopsy, with subsequent histological analysis, is the only sure way to confirm the presence of cancer cells. Various gastroscopic modalities have been developed to increase yield of detected mucosa with a dye that accentuates the cell structure and can identify areas of dysplasia. Endocytoscopy involves ultra-high magnification to visualise cellular structure to better determine areas of dysplasia. Other gastroscopic modalities such as

optical coherence tomography Optical coherence tomography (OCT) is an imaging technique that uses low-coherence light to capture micrometer-resolution, two- and three-dimensional images from within optical scattering media (e.g., biological tissue). It is used for medical ...

are being tested investigationally for similar applications. A number of

cutaneous condition A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of thi ...

s are associated with gastric cancer. A condition of darkened

hyperplasia Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of organic tissue that results from cell proliferati ...

of the skin, frequently of the

axilla The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded superior ...

and groin, known as

acanthosis nigricans Acanthosis nigricans is a medical sign characterised by brown-to-black, poorly defined, velvety hyperpigmentation of the skin. It is usually found in body folds, such as the posterior and lateral folds of the neck, the armpits, groin, navel, fore ...

, is associated with intra-abdominal cancers such as gastric cancer. Other cutaneous manifestations of gastric cancer include "tripe palms" (a similar darkening hyperplasia of the skin of the palms) and the Leser-Trelat sign, which is the rapid development of skin lesions known as seborrheic keratoses. Various blood tests may be done, including a

complete blood count A complete blood count (CBC), also known as a full blood count (FBC), is a set of medical laboratory tests that provide cytometry, information about the cells in a person's blood. The CBC indicates the counts of white blood cells, red blood cell ...

to check for anaemia, and a

fecal occult blood test Fecal occult blood (FOB) refers to blood in the feces that is not visibly apparent (unlike other types of blood in stool such as melena or hematochezia). A fecal occult blood test (FOBT) checks for hidden (occult) blood in the stool (feces). ...

to check for blood in the stool.

Histopathology

Pie chart of stomach cancer types by relative incidence

* ''Gastric

adenocarcinoma Adenocarcinoma (; plural adenocarcinomas or adenocarcinomata ) (AC) is a type of cancerous tumor that can occur in several parts of the body. It is defined as neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or ...

'' is a malignant epithelial tumour, originating from glandular epithelium of the gastric mucosa. Stomach cancers are about 90%

. Histologically, there are two major types of gastric adenocarcinoma ( Lauren classification): intestinal type or diffuse type. Adenocarcinomas tend to aggressively invade the gastric wall, infiltrating the

muscularis mucosae The lamina muscularis mucosae (or muscularis mucosae) is a thin layer (lamina) of muscle of the gastrointestinal tract, located outside the lamina propria, and separating it from the submucosa. It is present in a continuous fashion from the es ...

, the

submucosa The submucosa (or tela submucosa) is a thin layer of tissue (biology), tissue in various organ (anatomy), organs of the gastrointestinal tract, gastrointestinal, respiratory tract, respiratory, and genitourinary system, genitourinary tracts. It i ...

and then the

muscularis propria The muscular layer (muscular coat, muscular fibers, muscularis propria, muscularis externa) is a region of muscle in many organs in the vertebrate body, adjacent to the submucosa. It is responsible for gut movement such as peristalsis. The Latin, ...

. Intestinal type adenocarcinoma tumour cells describe irregular tubular structures, harbouring pluristratification, multiple lumens, reduced stroma ("back to back" aspect). Often, it associates intestinal metaplasia in neighbouring mucosa. Depending on glandular architecture, cellular pleomorphism and mucosecretion, adenocarcinoma may present 3 degrees of differentiation: well, moderate and poorly differentiated. Diffuse type adenocarcinoma (mucinous, colloid,

linitis plastica Linitis plastica is a widely used term for Brinton's disease (also known as leather bottle stomach), a morphological variant of diffuse (or infiltrating) stomach cancer. In some texts, the term is also used to describe the condition of a rigid, no ...

or leather-bottle stomach) tumour cells are discohesive and secrete mucus, which is delivered in the interstitium, producing large pools of mucus/colloid (optically "empty" spaces). It is poorly differentiated. In signet-ring cell carcinomas, the mucus remains inside the tumour cell and pushes the nucleus to the periphery, giving rise to

signet-ring cell In histology, a signet ring cell is a cell with a large vacuole. The malignant type is seen predominantly in carcinomas. Signet ring cells are most frequently associated with stomach cancer, but can arise from any number of tissues including the ...

s. * Around 5% of gastric cancers are lymphomas. These may include extranodal marginal zone B-cell lymphomas (MALT type) and to a lesser extent

diffuse large B-cell lymphoma Diffuse large B-cell lymphoma (DLBCL) is a cancer of B cells, a type of lymphocyte that is responsible for producing antibody, antibodies. It is the most common form of non-Hodgkin lymphoma among adults, with an annual Incidence (epidemiology), in ...

s. MALT type make up about half of stomach lymphomas. *

Carcinoid A carcinoid (also carcinoid tumor) is a slow-growing type of neuroendocrine tumor originating in the cells of the neuroendocrine system. In some cases, metastasis may occur. Carcinoid tumors of the midgut (jejunum, ileum, appendix, and cecum) ...

and stromal tumors may occur. File:Adenocarcinoma low differentiated (stomach) H&E magn 400x.jpg, Poor to moderately differentiated adenocarcinoma of the stomach.

H&E stain Hematoxylin and eosin stain ( or haematoxylin and eosin stain or hematoxylin-eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diagnos ...

. File:Gastric signet ring cell carcinoma histopatholgy (1).jpg, Gastric

signet ring cell carcinoma Signet ring cell carcinoma (SRCC) is a rare form of highly malignant adenocarcinoma that produces mucin. It is an epithelial malignancy characterized by the histologic appearance of signet ring cells. Primary SRCC tumors are most often found in t ...

. File:Gastric adenocarcinoma.jpg, Adenocarcinoma of the stomach and

Staging

Diagram showing the T stages of stomach cancer CRUK 374

If cancer cells are found in the tissue sample, the next step is to

stage Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * Sta ...

, or find out the extent of the disease. Various tests determine whether the cancer has spread, and if so, what parts of the body are affected. Because stomach cancer can spread to the liver, pancreas, and other organs near the stomach, as well as to the lungs, the doctor may order a CT scan, a

PET scan Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, r ...

, an

endoscopic ultrasound Endoscopic ultrasound (EUS) or echo-endoscopy is a medical procedure in which endoscopy (insertion of a probe into a hollow organ) is combined with ultrasound to obtain images of the internal organs in the chest, abdomen and colon. It can be used ...

exam, or other tests to check these areas. Blood tests for

tumor marker A tumor marker is a biomarker found in blood, urine, or body tissues that can be elevated by the presence of one or more types of cancer. There are many different tumor markers, each indicative of a particular disease process, and they are used in ...

s, such as

carcinoembryonic antigen Carcinoembryonic antigen (CEA) describes a set of highly related glycoproteins involved in cell adhesion. CEA is normally produced in gastrointestinal tissue during fetal development, but the production stops before birth. Consequently, CEA is ...

and carbohydrate antigen may be ordered, as their levels correlate to extent of metastasis, especially to the liver, and the cure rate. Staging may not be complete until after surgery. The surgeon removes nearby lymph nodes and possibly samples of tissue from other areas in the abdomen for examination by a pathologist. The clinical stages of stomach cancer are: * Stage 0 – Limited to the inner lining of the stomach, it is treatable by endoscopic mucosal resection when found very early (in routine screenings), or otherwise by

gastrectomy A gastrectomy is a partial or total surgical removal of the stomach. Indications Gastrectomies are performed to treat stomach cancer and perforations of the stomach wall. In severe duodenal ulcers it may be necessary to remove the lower port ...

and

lymphadenectomy Lymphadenectomy or lymph node dissection is the surgical removal of one or more groups of lymph nodes. It is almost always performed as part of the surgical management of cancer. In a regional lymph node dissection, some of the lymph nodes in the ...

without need for chemotherapy or radiation. * Stage I – Penetration to the second or third layers of the stomach (stage 1A) or to the second layer and nearby

lymph nodes A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that inclu ...

(stage 1B): Stage 1A is treated by surgery, including removal of the omentum. Stage 1B may be treated with chemotherapy ( 5-fluorouracil) and radiation therapy. * Stage II – Penetration to the second layer and more distant lymph nodes, or the third layer and only nearby lymph nodes, or all four layers but not the lymph nodes, it is treated as for stage I, sometimes with additional neoadjuvant chemotherapy. * Stage III – Penetration to the third layer and more distant lymph nodes, or penetration to the fourth layer and either nearby tissues or nearby or more distant lymph nodes, it is treated as for stage II; a cure is still possible in some cases. * Stage IV – Cancer has spread to nearby tissues and more distant lymph nodes, or has

metastasize Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...

d to other organs. A cure is very rarely possible at this stage. Some other techniques to prolong life or improve symptoms are used, including laser treatment, surgery, and/or stents to keep the digestive tract open, and chemotherapy by drugs such as 5-fluorouracil,

cisplatin Cisplatin is a chemotherapy medication used to treat a number of cancers. These include testicular cancer, ovarian cancer, cervical cancer, breast cancer, bladder cancer, head and neck cancer, esophageal cancer, lung cancer, mesothelioma, br ...

epirubicin Epirubicin is an anthracycline drug used for chemotherapy. It can be used in combination with other medications to treat breast cancer in patients who have had surgery to remove the tumor. It is marketed by Pfizer under the trade name Ellence in ...

etoposide Etoposide, sold under the brand name Vepesid among others, is a chemotherapy medication used for the treatments of a number of types of cancer including testicular cancer, lung cancer, lymphoma, leukemia, neuroblastoma, and ovarian cancer. It is ...

docetaxel Docetaxel (DTX or DXL), sold under the brand name Taxotere among others, is a chemotherapy medication used to treat a number of types of cancer. This includes breast cancer, head and neck cancer, stomach cancer, prostate cancer and non-small-ce ...

, oxaliplatin,

capecitabine Capecitabine, sold under the brand name Xeloda among others, is a chemotherapy medication used to treat breast cancer, gastric cancer and colorectal cancer. For breast cancer it is often used together with docetaxel. It is taken by mouth. Comm ...

, or

irinotecan Irinotecan, sold under the brand name Camptosar among others, is a medication used to treat colon cancer, and small cell lung cancer. For colon cancer it is used either alone or with fluorouracil. For small cell lung cancer it is used with cisp ...

Diagram showing secondary stomach cancer in the lungs CRUK 186

The

TNM staging system The TNM Classification of Malignant Tumors (TNM) is a globally recognised standard for classifying the extent of spread of cancer. It is a classification system of the anatomical extent of tumor cancers. It has gained wide international acceptance ...

is also used. In a study of open-access endoscopy in

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

, patients were diagnosed 7% in stage I, 17% in stage II, and 28% in stage III. A Minnesota population was diagnosed 10% in stage I, 13% in stage II, and 18% in stage III. However, in a high-risk population in the

Valdivia Province Valdivia Province ( es, Provincia de Valdivia; ) is one of two provinces of the southern Chilean region of Los Ríos (XIV). The provincial capital is Valdivia. Located in the province are two important rivers, the Calle-Calle / Valdivia River ...

of southern

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, only 5% of patients were diagnosed in the first two stages and 10% in stage III.

Prevention

Getting rid of ''H. pylori'' in those who are infected decreases the risk of stomach cancer. A 2014 meta-analysis of observational studies found that a diet high in

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

mushrooms A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the na ...

garlic Garlic (''Allium sativum'') is a species of bulbous flowering plant in the genus ''Allium''. Its close relatives include the onion, shallot, leek, chive, Allium fistulosum, Welsh onion and Allium chinense, Chinese onion. It is native to South A ...

soybean The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean, which has numerous uses. Traditional unfermented food uses of soybeans include soy milk, from which tofu an ...

s, and

green onion Scallions (also known as spring onions or green onions) are vegetables derived from various species in the genus ''Allium''. Scallions generally have a milder taste than most onions and their close relatives include garlic, shallot, leek, ...

s was associated with a lower risk of stomach cancer in the Korean population. Low doses of

vitamin A vitamin is an organic molecule (or a set of molecules closely related chemically, i.e. vitamers) that is an Nutrient#Essential nutrients, essential micronutrient that an organism needs in small quantities for the proper functioning of its ...

s, especially from a healthy diet, decrease the risk of stomach cancer. A previous review of

supplementation did not find supporting evidence and possibly worse outcomes. Modern technology is used to promote early diagnosis, e.g. based on serum markers.

Management

Cancer of the stomach is difficult to cure unless it is found at an early stage (before it has begun to spread). Unfortunately, because early stomach cancer causes few symptoms, the disease is usually advanced when the diagnosis is made. Treatment for stomach cancer may include surgery,

, or

. New treatment approaches such as

immunotherapy Immunotherapy or biological therapy is the treatment of disease by activating or suppressing the immune system. Immunotherapies designed to elicit or amplify an immune response are classified as ''activation immunotherapies,'' while immunotherap ...

gene therapy Gene therapy is a medical field which focuses on the genetic modification of cells to produce a therapeutic effect or the treatment of disease by repairing or reconstructing defective genetic material. The first attempt at modifying human DN ...

and improved ways of using current methods are being studied in clinical trials.

Surgery

Surgery remains the only curative therapy for stomach cancer. Of the different surgical techniques,

endoscopic mucosal resection Endoscopic mucosal resection is a technique used to remove cancerous or other abnormal lesions found in the digestive tract. It is one method of performing a mucosectomy. For the esophagous Endoscopic mucosal resection has been advocated for ...

(EMR) is a treatment for early gastric cancer (tumor only involves the

mucosa A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...

) that was pioneered in Japan and is available in the United States at some centers. In EMR, the tumor, together with the inner lining of stomach (mucosa), is removed from the wall of the stomach using an electrical wire loop through the endoscope. The advantage is that it is a much smaller operation than removing the stomach.

Endoscopic submucosal dissection Endoscopic submucosal dissection (ESD) is an advanced surgery, surgical procedure using endoscopy to remove gastrointestinal cancer, gastrointestinal tumors that have not entered the muscle layer. ESD may be done in the esophagus, stomach or colon ...

is a similar technique pioneered in Japan, used to resect a large area of mucosa in one piece. If the pathologic examination of the resected specimen shows incomplete resection or deep invasion by tumor, the patient would need a formal stomach resection. A 2016

Cochrane review Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health profes ...

found low-quality evidence of no difference in short-term mortality between laparoscopic and open gastrectomy (removal of stomach), and that benefits or harms of laparoscopic gastrectomy cannot be ruled out. Post-operatively, up to 70% of people undergoing total gastrectomy develop complications such as dumping syndrome and reflux esophagitis. Construction of a "pouch", which serves as a "stomach substitute", reduced the incidence of dumping syndrome and reflux esophagitis by 73% and 63% respectively, and led to improvements in quality-of-life, nutritional outcomes, and body mass index. Those with metastatic disease at the time of presentation may receive palliative surgery, and while it remains controversial, due to the possibility of complications from the surgery itself and because it may delay chemotherapy, the data so far are mostly positive, with improved survival rates being seen in those treated with this approach.

Chemotherapy

The use of chemotherapy to treat stomach cancer has no firmly established

standard of care In tort law, the standard of care is the only degree of prudence and caution required of an individual who is under a duty of care. The requirements of the standard are closely dependent on circumstances. Whether the standard of care has been b ...

. Unfortunately, stomach cancer has not been particularly sensitive to these drugs, and chemotherapy, if used, has usually served to palliatively reduce the size of the tumor, relieve symptoms of the disease, and increase survival time. Some drugs used in stomach cancer treatment have included: fluorouracil or its analog

, BCNU ( carmustine), methyl-CCNU (

semustine Semustine (1- (2-Chloroethyl)-3-(trans-4-methylcyclohexyl)- 1-nitrosourea, MeCCNU) is an alkylating nitrosourea compound used in chemotherapy treatment of various types of tumours. Due to its lipophilic property, semustine can cross the blood-bra ...

) and

doxorubicin Doxorubicin, sold under the brand name Adriamycin among others, is a chemotherapy medication used to treat cancer. This includes breast cancer, bladder cancer, Kaposi's sarcoma, lymphoma, and acute lymphocytic leukemia. It is often used toge ...

(Adriamycin), as well as

mitomycin C Mitomycin C is a mitomycin that is used as a chemotherapeutic agent by virtue of its antitumour activity. Medical uses It is given intravenously to treat upper gastro-intestinal cancers (e.g. esophageal carcinoma), anal cancers, and breast ...

, and more recently

and

taxotere Docetaxel (DTX or DXL), sold under the brand name Taxotere among others, is a chemotherapy medication used to treat a number of types of cancer. This includes breast cancer, head and neck cancer, stomach cancer, prostate cancer and non-small-ce ...

, often using drugs in various combinations. The relative benefits of these different drugs, alone and in combination, are unclear. Clinical researchers are exploring the benefits of giving chemotherapy before surgery to shrink the tumor, or as adjuvant therapy after surgery to destroy remaining cancer cells.

Targeted therapy

Recently, treatment with human epidermal growth factor receptor 2 (''HER2'') inhibitor,

trastuzumab Trastuzumab, sold under the brand name Herceptin among others, is a monoclonal antibody used to treat breast cancer and stomach cancer. It is specifically used for cancer that is HER2 receptor positive. It may be used by itself or together wi ...

, has been demonstrated to increase

overall survival Survival rate is a part of survival analysis. It is the proportion of people in a study or treatment group still alive at a given period of time after diagnosis. It is a method of describing prognosis in certain disease conditions, and can be use ...

in inoperable locally advanced or metastatic gastric carcinoma over-expressing the ''

HER2/neu Receptor tyrosine-protein kinase erbB-2 is a protein that in humans is encoded by the ''ERBB2'' gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The human protein is also frequently refer ...

'' gene. In particular, ''

HER2 Receptor tyrosine-protein kinase erbB-2 is a protein that in humans is encoded by the ''ERBB2'' gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The human protein is also frequently refer ...

'' is overexpressed in 13–22% of patients with gastric cancer. Of note, ''HER2'' overexpression in gastric neoplasia is heterogeneous and comprises a minority of tumor cells (less than 10% of gastric cancers overexpress ''HER2'' in more than 5% of tumor cells). Hence, this heterogeneous expression should be taken into account for ''HER2'' testing, particularly in small samples such as biopsies, requiring the evaluation of more than one bioptic sample.

Radiation

Radiation therapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...

(also called radiotherapy) may be used to treat stomach cancer, often as an adjuvant to chemotherapy and/or surgery.

Lymphoma

MALT lymphoma MALT lymphoma (MALToma) is a form of lymphoma involving the mucosa-associated lymphoid tissue (MALT), frequently of the stomach, but virtually any mucosal site can be affected. It is a cancer originating from B cells in the marginal zone of the MAL ...

s can often be fully treated by treating an underlying ''H. pylori'' infection. This results in remission in about 80% of cases.

Prognosis

The prognosis of stomach cancer is generally poor, because the tumor has often metastasized by the time of discovery, and most people with the condition are elderly (median age is between 70 and 75 years) at presentation. The average life expectancy after being diagnosed is around 24 months, and the five-year survival rate for stomach cancer is less than 10%. Almost 300 genes are related to outcomes in stomach cancer, with both unfavorable genes where high expression is related to poor survival and favorable genes where high expression is associated with longer survival times. Examples of poor prognosis genes include

ITGAV Integrin alpha-V is a protein that in humans is encoded by the ''ITGAV'' gene. Function ITGAV encodes integrin alpha chain V. Integrins are heterodimeric integral membrane proteins composed of an alpha chain and a beta chain. Alpha V undergoes ...

DUSP1 Dual specificity protein phosphatase 1 is an enzyme that in humans is encoded by the ''DUSP1'' gene. Function The expression of DUSP1 gene is induced in human skin fibroblasts by oxidative/heat stress and growth factors. It specifies a protei ...

and

P2RX7 P2X purinoceptor 7 is a protein that in humans is encoded by the ''P2RX7'' gene. The product of this gene belongs to the family of purinoceptors for ATP. Multiple alternatively spliced variants which would encode different isoforms have been id ...

Epidemiology

Stomach cancer world map-Deaths per million persons-WHO2012

Worldwide, stomach cancer is the fifth most-common cancer with 952,000 cases diagnosed in 2012. It is more common both in men and in developing countries. In 2012, it represented 8.5% of cancer cases in men, making it the fourth-most common cancer in men. Also in 2012, the number of deaths was 700,000, having decreased slightly from 774,000 in 1990, making it the third-leading cause of cancer-related death (after

lung cancer Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lung tumor characterized by uncontrolled cell growth in tissue (biology), tissues of the lung. Lung carcinomas derive from tran ...

and

liver cancer Liver cancer (also known as hepatic cancer, primary hepatic cancer, or primary hepatic malignancy) is cancer that starts in the liver. Liver cancer can be primary (starts in liver) or secondary (meaning cancer which has spread from elsewhere to th ...

). Less than 5% of stomach cancers occur in people under 40 years of age, with 81.1% of that 5% in the age-group of 30 to 39 and 18.9% in the age-group of 20 to 29. In 2014, stomach cancer resulted in 0.61% of deaths (13,303 cases) in the U.S. In China, stomach cancer accounted for 3.56% of all deaths (324,439 cases). The highest rate of stomach cancer was in

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...

, at 28 cases per 100,000 people. In the United Kingdom, stomach cancer is the 15th-most common cancer (around 7,100 people were diagnosed with stomach cancer in 2011), and it is the 10th-most common cause of cancer-related deaths (around 4,800 people died in 2012). Incidence and mortality rates of gastric cancer vary greatly in Africa. The GLOBOCAN system is currently the most widely used method to compare these rates between countries, but African incidence and mortality rates are seen to differ among countries, possibly due to the lack of universal access to a registry system for all countries. Variation as drastic as estimated rates from 0.3/100000 in Botswana to 20.3/100000 in Mali have been observed. In Uganda, the incidence of gastric cancer has increased from the 1960s measurement of 0.8/100000 to 5.6/100000. Gastric cancer, though present, is relatively low when compared to countries with high incidence like Japan and China. One suspected cause of the variation within Africa and between other countries is due to different strains of the ''H. pylori'' bacteria. The trend commonly seen is that ''H. pylori ''infection increases the risk for gastric cancer, but this is not the case in Africa, giving this phenomenon the name the "African enigma". Although this bacterial species is found in Africa, evidence has supported that different strains with mutations in the bacterial genotype may contribute to the difference in cancer development between African countries and others outside the continent. Increasing access to health care and treatment measures have been commonly associated with the rising incidence, though, particularly in Uganda.

Other animals

The stomach is a muscular organ of the

gastrointestinal The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...

tract that holds food and begins the digestive process by secreting gastric juice. The most common cancers of the stomach are adenocarcinomas, but other histological types have been reported. Signs vary, but may include vomiting (especially if blood is present), weight loss, anemia, and lack of appetite. Bowel movements may be dark and tarry in nature. To determine whether cancer is present in the stomach, special X-rays and/or abdominal ultrasounds may be performed.

Gastroscopy Esophagogastroduodenoscopy (EGD) or oesophagogastroduodenoscopy (OGD), also called by various other names, is a diagnostic endoscopic procedure that visualizes the upper part of the gastrointestinal tract down to the duodenum. It is considered ...

, a test using an endoscope to examine the stomach, is a useful diagnostic tool that can also take samples of the suspected mass for histopathological analysis to confirm or rule out cancer. The most definitive method of cancer diagnosis is through open surgical biopsy. Most stomach tumors are malignant with evidence of spread to lymph nodes or liver, making treatment difficult. Except for lymphoma, surgery is the most frequent treatment option for stomach cancers but it is associated with significant risks.

References

External links

* {{DEFAULTSORT:Stomach Cancer Abdomen Epstein–Barr virus–associated diseases Infectious causes of cancer Wikipedia medicine articles ready to translate