Oncology is a branch of

medicine Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...

that deals with the study, treatment, diagnosis, and prevention of

cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

. A medical professional who practices oncology is an ''oncologist''. The name's etymological origin is the Greek word ὄγκος (''ónkos''), meaning "tumor", "volume" or "mass". Oncology is focused on the

diagnosis Diagnosis (: diagnoses) is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in a lot of different academic discipline, disciplines, with variations in the use of logic, analytics, and experience, to determine " ...

of cancer in a person, therapy (e.g.,

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

chemotherapy Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...

radiotherapy Radiation therapy or radiotherapy (RT, RTx, or XRT) is a treatment using ionizing radiation, generally provided as part of cancer therapy to either kill or control the growth of malignant cells. It is normally delivered by a linear particle ...

and other modalities), monitoring of patients after treatment, palliative care of people with advanced-stage cancers,

ethical Ethics is the philosophical study of moral phenomena. Also called moral philosophy, it investigates normative questions about what people ought to do or which behavior is morally right. Its main branches include normative ethics, applied e ...

questions surrounding cancer care, screening of patients, and the study of cancer treatments through

clinical research Clinical research is a branch of medical research that involves people and aims to determine the effectiveness (efficacy) and safety of medications, devices, diagnostic products, and treatment regimens intended for improving human health. The ...

. An oncologist typically focuses on a specialty area in cancer treatment, such as surgery,

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infr ...

gynecologic oncology ''Gynecologic Oncology'' is a Peer review, peer-reviewed medical journal covering all aspects of gynecologic oncology. The journal covers investigations relating to the etiology, diagnosis, and treatment of female cancers, as well as research from ...

, geriatric oncology, pediatric oncology, and various organ-specific disciplines (breast, brain, liver, among others). The expertise of an oncologist is applied when cancer is suspected, diagnosed with, or treated from.

Diagnosis

Medical histories are still an important screening tool for an oncologist to assess the nature of concerns and nonspecific symptoms in a patient (such as

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

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 ...

, unexplained

anemia Anemia (also spelt anaemia in British English) is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin availabl ...

, fever of unknown origin, paraneoplastic phenomena and other signs) that may require further evaluation for malignancy. Diagnostic methods in oncology may include a

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, an interventional radiologist, or an interventional cardiology, interventional cardiologist. The process involves the extraction of sampling (medicine), sample ...

or resection; these are methods used to remove suspicious neoplastic growths can be removed in part or in whole, and examined by a pathologist to assess for malignancy. This is currently the gold standard for the diagnosis of cancer and is essential for determining the next step in the appropriate course of management (active surveillance, surgery, radiation therapy, chemotherapy, or a combination of these). Other diagnostic procedures may include an

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 ...

, either upper or lower gastrointestinal, cystoscopy, bronchoscopy, or nasendoscopy to localize tissues suspicious for malignancy and biopsy, mammograms,

X-rays An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

, CT scanning, MRI scanning,

ultrasound Ultrasound is sound with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...

and other radiological techniques to localize and guide biopsy.

Scintigraphy Scintigraphy (from Latin ''scintilla'', "spark"), also known as a gamma scan, is a diagnostic test in nuclear medicine, where radioisotopes attached to drugs that travel to a specific organ or tissue (radiopharmaceuticals) are taken internally a ...

, single photon emission computed tomography (SPECT),

positron emission tomography 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 ...

(PET) and other methods of

nuclear medicine Nuclear medicine (nuclear radiology, nucleology), is a medical specialty involving the application of radioactivity, radioactive substances in the diagnosis and treatment of disease. Nuclear imaging is, in a sense, ''radiology done inside out'', ...

are imaging technologies used to identify areas suspicious of malignancy.

Blood test A blood test is a medical laboratory, laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose ...

s, including

tumor marker A tumor marker is a biomarker that can be used to indicate the presence of cancer or the behavior of cancers (measure progression or response to therapy). They can be found in bodily fluids or tissue. Markers can help with assessing prognosis, s ...

s, can assist diagnosis of certain types of cancers. Apart from diagnoses, these modalities (especially imaging by CT scanning) are often used to determine operability, i.e., whether it is surgically possible to remove a tumor in its entirety. A tissue diagnosis (from a

) by a pathologist is essential for the proper classification of

and to guide the next step of treatment. On extremely rare instances when this is not possible, "empirical therapy" (without an exact diagnosis) may be considered, based on the available evidence (e.g. history, x-rays and scans.) Immunohistochemical markers often give a strong indication of the primary malignancy. This situation is referred to as " malignancy of unknown primary", and again, treatment is empirically based on past experience of the most likely origin.

Therapy

Treament or palliative care depends on the cancer. Certain disorders (such as ALL or AML) will require immediate admission and

. Others may be followed up with regular physical examination,

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 revea ...

, and

blood test A blood test is a medical laboratory, laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose ...

s. Often,

is attempted to remove a

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

entirely. This is only feasible when there is some degree of certainty that the tumor can in fact be removed. When it is certain that parts will remain, curative surgery is often impossible, e.g. when there are

metastases Metastasis is a pathogenic agent's spreading 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, ...

, or when the tumor has invaded a structure that cannot be operated upon without risking the patient's life. Occasionally surgery can improve survival even if not all tumour tissue has been removed; the procedure is referred to as "debulking" (i.e. reducing the overall amount of tumour tissue). Surgery is also used for the palliative treatment of some cancers, e.g. to relieve biliary obstruction, or to relieve the problems associated with some cerebral tumors. The risks of surgery must be weighed against the benefits.

Chemotherapy Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...

and

are used as a first-line radical therapy in several malignancies. They are also used for adjuvant therapy, i.e. when the macroscopic tumor has already been completely removed surgically but there is a reasonable statistical risk that it will recur. Chemotherapy and radiotherapy are commonly used for palliation, where disease is clearly incurable: in this situation the aim is to improve the quality of life and to prolong it.

Hormone A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...

manipulation is well established, particularly in the treatment of breast and prostate cancer.

Monoclonal antibody A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell. Monoclonal antibodie ...

treatments are widely used in oncology, with established therapies such as

Rituximab Rituximab, sold under the brand name Rituxan among others, is a monoclonal antibody medication used to treat certain autoimmune diseases and types of cancer. It is used for non-Hodgkin lymphoma, chronic lymphocytic leukemia (in children and ad ...

for lymphoma and

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 ...

for HER2-positive breast cancer, alongside newer agents targeting various cancers. Cancer vaccines and other

immunotherapies 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 ...

, such as checkpoint inhibitors, CAR-T cell therapy, and cytokine therapies, remain active areas of research and clinical application.

Palliative care

Approximately 50% of all cancer cases in the Western world can be treated to remission with radical treatment. For pediatric patients, that number is much higher. A large number of cancer patients will die from the disease, and a significant proportion of patients with incurable cancer will die of other causes. There may be ongoing issues with symptom control associated with progressive cancer, and also with the treatment of the disease. These problems may include

pain Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

, anorexia,

, immobility, and depression. Not all issues are strictly physical: personal dignity may be affected. Moral and spiritual issues are also important. While many of these problems fall within the remit of the oncologist, palliative care has matured into a separate, closely allied specialty to address the problems associated with advanced disease. Palliative care is an essential part of the multidisciplinary cancer care team. Palliative care services may be less hospital-based than oncology, with nurses and doctors who are able to visit the patient at home.

Ethical issues

There are a number of recurring

questions and dilemmas in oncological practice. These include: * What information to give the patient regarding disease extent/progression/

prognosis Prognosis ( Greek: πρόγνωσις "fore-knowing, foreseeing"; : prognoses) is a medical term for predicting the likelihood or expected development of a disease, including whether the signs and symptoms will improve or worsen (and how quickly) ...

. * Entry into

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

, especially in the face of terminal illness. * Withdrawal of active treatment. * " Do Not Resuscitate" orders and other end-of-life issues. These issues are closely related to the patient's personality, religion, culture, and family life. Though these issues are complex and emotional, the answers are often achieved by the patient seeking counsel from trusted personal friends and advisors. It requires a degree of sensitivity and very good communication on the part of the oncology team to address these problems properly.

Progress and research

There is a tremendous amount of research being conducted on all frontiers of oncology, ranging from cancer cell biology, and radiation therapy to

treatment regimens and optimal palliative care and pain relief. Next-generation sequencing and whole-genome sequencing have completely changed the understanding of cancers. Identification of novel genetic/molecular markers will change the methods of diagnosis and treatment, paving the way for personalized medicine. Therapeutic trials often involve patients from many different hospitals in a particular region. In the UK, patients are often enrolled in large studies coordinated by Cancer Research UK (CRUK), Medical Research Council (MRC), the European Organisation for Research and Treatment of Cancer (EORTC) or the National Cancer Research Network (NCRN). The most valued companies worldwide whose leading products are in Oncology include

Pfizer Pfizer Inc. ( ) is an American Multinational corporation, multinational Pharmaceutical industry, pharmaceutical and biotechnology corporation headquartered at The Spiral (New York City), The Spiral in Manhattan, New York City. Founded in 184 ...

(United States), Roche (Switzerland), Merck (United States),

AstraZeneca AstraZeneca plc () (AZ) is a British-Swedish multinational pharmaceutical and biotechnology company with its headquarters at the Cambridge Biomedical Campus in Cambridge, UK. It has a portfolio of products for major diseases in areas includi ...

(United Kingdom),

Novartis Novartis AG is a Swiss multinational corporation, multinational pharmaceutical company, pharmaceutical corporation based in Basel, Switzerland. Novartis is one of the largest pharmaceutical companies in the world and was the eighth largest by re ...

(Switzerland) and Bristol-Myers Squibb (United States) who are active in the treatment areas Kinase inhibitors,

Antibodies An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as bacteria and viruses, including those that caus ...

, Immuno-oncology and Radiopharmaceuticals.

Specialties

* The four main divisions: ** Clinical oncology: focuses on treatment of cancer with both systemic therapies and radiation. ** Medical oncology: focuses on the treatment of cancer with

, targeted therapy, immunotherapy, and hormonal therapy. ** Radiation oncology: focuses on treatment of cancer with radiation. ** Surgical oncology: focuses on treatment of cancer with surgery. * Sub-specialties in Oncology: ** Adolescent and young adult (AYA) oncology. **

Bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

& Musculoskeletal oncology: focuses on cancers of bones and soft tissue. ** Breast oncology: focuses on cancers of breast. ** Cardiooncology (an Emerging specialty) is a branch of cardiology that addresses the cardiovascular impact of cancer and its treatments. ** Dermatological oncology: focuses on the medical and surgical treatment of skin, hair, sweat gland, and nail cancers ** Gastrointestinal oncology: focuses on cancers of the stomach, colon, rectum, anal canal, liver, gallbladder, pancreas. ** Genitourinary oncology: focuses on cancers of genital and urinary system. ** Geriatric oncology: focuses on cancers in elderly population. **

Gynecologic oncology ''Gynecologic Oncology'' is a Peer review, peer-reviewed medical journal covering all aspects of gynecologic oncology. The journal covers investigations relating to the etiology, diagnosis, and treatment of female cancers, as well as research from ...

: focuses on cancers of the female reproductive system. ** Head & Neck oncology: focuses on cancers of oral cavity, nasal cavity, oropharynx, hypopharynx and larynx. ** Hemato oncology: focuses on cancers of blood and stem cell transplantation. ** Mathematical oncology **

Molecular oncology Molecular oncology is an interdisciplinary medical specialty at the interface of medicinal chemistry and oncology that refers to the investigation of the chemistry of cancer and tumors at the molecule, molecular scale. Also the development and app ...

: focuses on molecular diagnostic methods in oncology. ** Neuro-oncology: focuses on cancers of brain. ** Nuclear medicine oncology: focuses on diagnosis and treatment of cancer with radiopharmaceuticals. ** Ocular oncology: focuses on cancers of eye. ** Pain & Palliative oncology: focuses on treatment of end stage cancer to help alleviate pain and suffering. ** Pediatric oncology: concerned with the treatment of cancer in children. ** Preventive oncology: focuses on epidemiology & prevention of cancer. ** Psycho-oncology: focuses on psychosocial issues on diagnosis and treatment of cancer patients. **

Thoracic The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main ...

oncology: focuses on cancers of lung, mediastinum, oesophagus and pleura. ** Veterinary oncology: focuses on treatment of cancer in animals.

References

External links

* * * {{Authority control : Medical specialties