Skin Cancer
   HOME

TheInfoList



OR:

Skin cancers are
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 ...
s that arise from the
skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
. They are due to the development of abnormal cells that have the ability to invade or
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 ...
to other parts of the body. There are three main types of skin cancers:
basal-cell skin cancer Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer. It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it. It may also present as a raise ...
(BCC),
squamous-cell skin cancer Squamous-cell skin cancer, also known as cutaneous squamous-cell carcinoma (cSCC), is one of the main types of skin cancer along with basal cell cancer and melanoma. It usually presents as a hard lump with a scaly top but can also form an ulcer. O ...
(SCC) and
melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...
. The first two, along with a number of less common skin cancers, are known as nonmelanoma skin cancer (NMSC). Basal-cell cancer grows slowly and can damage the tissue around it but is unlikely to spread to distant areas or result in death. It often appears as a painless raised area of skin that may be shiny with small blood vessels running over it or may present as a raised area with an
ulcer An ulcer is a discontinuity or break in a bodily membrane that impedes normal function of the affected organ. According to Robbins's pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughing o ...
. Squamous-cell skin cancer is more likely to spread. It usually presents as a hard lump with a scaly top but may also form an ulcer. Melanomas are the most aggressive. Signs include a
mole Mole (or Molé) may refer to: Animals * Mole (animal) or "true mole", mammals in the family Talpidae, found in Eurasia and North America * Golden moles, southern African mammals in the family Chrysochloridae, similar to but unrelated to Talpida ...
that has changed in size, shape, color, has irregular edges, has more than one color, is itchy or bleeds. More than 90% of cases are caused by exposure to
ultraviolet radiation Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30  PHz) to 400 nm (750  THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...
from the
Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
. This exposure increases the risk of all three main types of skin cancer. Exposure has increased, partly due to a thinner
ozone layer The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. It contains a high concentration of ozone (O3) in relation to other parts of the atmosphere, although still small in rela ...
.
Tanning beds Indoor tanning involves using a device that emits ultraviolet radiation to produce a cosmetic tan. Typically found in tanning salons, gyms, spas, hotels, and sporting facilities, and less often in private residences, the most common device is a ho ...
are another common source of ultraviolet radiation. For melanomas and basal-cell cancers, exposure during childhood is particularly harmful. For squamous-cell skin cancers, total exposure, irrespective of when it occurs, is more important. Between 20% and 30% of melanomas develop from moles. People with lighter skin are at higher risk as are those with poor immune function such as from medications or
HIV/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 ...
. Diagnosis is 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 dise ...
. Decreasing exposure to ultraviolet radiation and the use of sunscreen appear to be effective methods of preventing melanoma and squamous-cell skin cancer. It is not clear if sunscreen affects the risk of basal-cell cancer. Nonmelanoma skin cancer is usually curable. Treatment is generally by surgical removal but may, less commonly, involve
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. Radi ...
or topical medications such as
fluorouracil Fluorouracil (5-FU), sold under the brand name Adrucil among others, is a cytotoxic chemotherapy medication used to treat cancer. By intravenous injection it is used for treatment of colorectal cancer, oesophageal cancer, stomach cancer, pan ...
. Treatment of melanoma may involve 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. Radi ...
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 ...
. In those people whose disease has spread to other areas of the body,
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 used to improve quality of life. Melanoma has one of the higher survival rates among cancers, with over 86% of people in the UK and more than 90% in the United States surviving more than 5 years. Skin cancer is the most common form of cancer, globally accounting for at least 40% of cancer cases. The most common type is nonmelanoma skin cancer, which occurs in at least 2–3 million people per year. This is a rough estimate, however, as good statistics are not kept. Of nonmelanoma skin cancers, about 80% are basal-cell cancers and 20% squamous-cell skin cancers. Basal-cell and squamous-cell skin cancers rarely result in death. In the United States, they were the cause of less than 0.1% of all cancer deaths. Globally in 2012, melanoma occurred in 232,000 people and resulted in 55,000 deaths. White people in
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
,
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
and
South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
have the highest rates of melanoma in the world. The three main types of skin cancer have become more common in the last 20 to 40 years, especially regions where the population is predominantly White.


Classification

There are three main types of skin cancer:
basal-cell skin cancer Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer. It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it. It may also present as a raise ...
(basal-cell carcinoma) (BCC),
squamous-cell skin cancer Squamous-cell skin cancer, also known as cutaneous squamous-cell carcinoma (cSCC), is one of the main types of skin cancer along with basal cell cancer and melanoma. It usually presents as a hard lump with a scaly top but can also form an ulcer. O ...
(squamous-cell carcinoma) (SCC) and
malignant melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the Biological pigment, pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, i ...
. Basal-cell carcinomas are most commonly present on sun-exposed areas of the skin, especially the face. They rarely metastasize and rarely cause death. They are easily treated with surgery or radiation. Squamous-cell skin cancers are also common, but much less common than basal-cell cancers. They metastasize more frequently than BCCs. Even then, the metastasis rate is quite low, with the exception of SCC of the lip, ear, and in people who are immunosuppressed. Melanoma are the least frequent of the three common skin cancers. They frequently metastasize, and potentially cause death once they spread. Less common skin cancers include:
dermatofibrosarcoma protuberans Dermatofibrosarcoma protuberans (DFSP) is a rare locally aggressive malignant cutaneous soft-tissue sarcoma. DFSP develops in the connective tissue cells in the middle layer of the skin (dermis). Estimates of the overall occurrence of DFSP in the ...
,
Merkel cell carcinoma Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer occurring in about 3 people per 1,000,000 members of the population. It is also known as cutaneous APUDoma, primary neuroendocrine carcinoma of the skin, primary small cell carcin ...
,
Kaposi's sarcoma Kaposi's sarcoma (KS) is a type of cancer that can form masses in the skin, in lymph nodes, in the mouth, or in other organs. The skin lesions are usually painless, purple and may be flat or raised. Lesions can occur singly, multiply in a limit ...
,
keratoacanthoma Keratoacanthoma (KA) is a common low-grade (unlikely to metastasize or invade) rapidly-growing skin tumour that is believed to originate from the hair follicle (pilosebaceous unit) and can resemble squamous cell carcinoma. The defining characteris ...
, spindle cell tumors,
sebaceous carcinoma Sebaceous carcinoma, also known as sebaceous gland carcinoma (SGc), sebaceous cell carcinoma, and meibomian gland carcinoma is an uncommon malignant cutaneous tumor. Most are typically about 1.4 cm at presentation. SGc originates from sebaceous ...
s,
microcystic adnexal carcinoma Microcystic adnexal carcinoma (MAC) is a rare sweat gland cancer, which often appears as a yellow spot or bump in the skin. It usually occurs in the neck or head, although cases have been documented in other areas of the body. Most diagnosis occur ...
,
Paget's disease of the breast Paget's disease of the breast is a type of cancer that outwardly may have the appearance of eczema, with skin changes involving the nipple of the breast. The condition is an uncommon disease accounting for 1 to 4.3% of all breast cancers and was ...
, atypical fibroxanthoma,
leiomyosarcoma Leiomyosarcoma is a malignant (cancerous) smooth muscle tumor. A benign tumor originating from the same tissue is termed leiomyoma. While leiomyosarcomas are not thought to arise from leiomyomas, some leiomyoma variants' classification is evolv ...
, and
angiosarcoma Angiosarcoma is a rare and aggressive cancer that starts in the endothelial cells that line the walls of blood vessels or lymphatic vessels. Since they are made from vascular lining, they can appear anywhere and at any age, but older people are ...
, and porocarcinoma. BCC and SCC often carry a UV-signature mutation indicating that these cancers are caused by
UVB Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30  PHz) to 400 nm (750  THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...
radiation via direct DNA damage. However malignant melanoma is predominantly caused by UVA radiation via indirect DNA damage. The indirect DNA damage is caused by free radicals and reactive oxygen species. Research indicates that the absorption of three sunscreen ingredients into the skin, combined with a 60-minute exposure to UV, leads to an increase of free radicals in the skin, if applied in too little quantity and too infrequently. However, the researchers add that newer creams often do not contain these specific compounds, and that the combination of other ingredients tends to retain the compounds on the surface of the skin. They also add that frequent re-application reduces the risk of radical formation.


Signs and symptoms

There are a variety of different skin cancer symptoms. These include changes in the
skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
that do not heal, ulcering in the skin, discolored skin, and changes in existing
moles Moles can refer to: * Moles de Xert, a mountain range in the Baix Maestrat comarca, Valencian Community, Spain * The Moles (Australian band) *The Moles, alter ego of Scottish band Simon Dupree and the Big Sound People *Abraham Moles, French engin ...
, such as jagged edges to the mole, enlargement of the mole, changes in color, the way it feels or if it bleeds. Other common signs of skin cancer can be painful lesion that itches or burns and large brownish spot with darker speckles.


Basal-cell skin cancer

Basal-cell skin cancer (BCC) usually presents as a raised, smooth, pearly bump on the sun-exposed skin of the head, neck,
torso The torso or trunk is an anatomical term for the central part, or the core, of the body of many animals (including humans), from which the head, neck, limbs, tail and other appendages extend. The tetrapod torso — including that of a huma ...
or
shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder mak ...
s. Sometimes small
blood vessel The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away ...
s (called
telangiectasia Telangiectasias, also known as spider veins, are small dilated blood vessels that can occur near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. These dilated blood vessels can develop anywhere on ...
) can be seen within the tumor. Crusting and bleeding in the center of the tumor frequently develops. It is often mistaken for a sore that does not heal. This form of skin cancer is the least deadly, and with proper treatment can be eliminated, often without significant scarring.


Squamous-cell skin cancer

Squamous-cell skin cancer (SCC) is commonly a red, scaling, thickened patch on sun-exposed skin. Some are firm hard nodules and dome shaped like
keratoacanthoma Keratoacanthoma (KA) is a common low-grade (unlikely to metastasize or invade) rapidly-growing skin tumour that is believed to originate from the hair follicle (pilosebaceous unit) and can resemble squamous cell carcinoma. The defining characteris ...
s. Ulceration and bleeding may occur. When SCC is not treated, it may develop into a large mass. Squamous-cell is the second most common skin cancer. It is dangerous, but not nearly as dangerous as a melanoma.


Melanoma

Most melanoma consist of various colours from shades of brown to black. A small number of melanoma are pink, red or fleshy in colour; these are called amelanotic melanoma and tend to be more aggressive. Warning signs of malignant melanoma include change in the size, shape, color or elevation of a mole. Other signs are the appearance of a new mole during adulthood or pain, itching, ulceration, redness around the site, or bleeding at the site. An often-used mnemonic is "ABCDE", where A is for "asymmetrical", B for "borders" (irregular: "Coast of Maine sign"), C for "color" (variegated), D for "diameter" (larger than 6 mm – the size of a pencil eraser) and E for "evolving."


Other

Merkel cell Merkel cells, also known as Merkel-Ranvier cells or tactile epithelial cells, are oval-shaped mechanoreceptors essential for light touch sensation and found in the skin of vertebrates. They are abundant in highly sensitive skin like that of the f ...
carcinomas are most often rapidly growing, non-tender red, purple or skin colored bumps that are not painful or itchy. They may be mistaken for a cyst or another type of cancer.


Causes

Ultraviolet radiation from sun exposure is the primary environmental cause of skin cancer. This can occur in professions such as farming. Other risk factors that play a role include: * Light skin color * Age * Smoking
tobacco Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...
*
HPV Human papillomavirus infection (HPV infection) is caused by a DNA virus from the '' Papillomaviridae'' family. Many HPV infections cause no symptoms and 90% resolve spontaneously within two years. In some cases, an HPV infection persists and re ...
infections increase the risk of squamous-cell skin cancer. * Some genetic syndromes including
congenital melanocytic nevi syndrome The congenital melanocytic nevus is a type of melanocytic nevus (or mole) found in infants at birth. This type of birthmark occurs in an estimated 1% of infants worldwide; it is located in the area of the head and neck 15% of the time. Signs an ...
which is characterized by the presence of
nevi Nevus (plural nevi) is a nonspecific medical term for a visible, circumscribed, chronic lesion of the skin or mucosa. The term originates from ''nævus'', which is Latin for "birthmark"; however, a nevus can be either congenital (present at bir ...
(birthmarks or moles) of varying size which are either present at birth, or appear within 6 months of birth. Nevi larger than 20 mm (3/4") in size are at higher risk for becoming cancerous. * Chronic non-healing wounds. These are called Marjolin's ulcers based on their appearance, and can develop into squamous-cell skin cancer. *
Ionizing radiation Ionizing radiation (or ionising radiation), including nuclear radiation, consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. Some particles can travel ...
such as X-rays, environmental
carcinogens A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive subs ...
, and artificial UV radiation (e.g.
tanning beds Indoor tanning involves using a device that emits ultraviolet radiation to produce a cosmetic tan. Typically found in tanning salons, gyms, spas, hotels, and sporting facilities, and less often in private residences, the most common device is a ho ...
). It is believed that tanning beds are the cause of hundreds of thousands of basal and squamous-cell skin cancer. The World Health Organization now places people who use artificial tanning beds in its highest risk category for skin cancer. Alcohol consumption, specifically excessive drinking increase the risk of sunburns. * The use of many
immunosuppressive Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse reacti ...
medications increases the risk of skin cancer.
Cyclosporin A Ciclosporin, also spelled cyclosporine and cyclosporin, is a calcineurin inhibitor, used as an immunosuppressant medication. It is a natural product. It is taken orally or intravenously for rheumatoid arthritis, psoriasis, Crohn's disease ...
, a
calcineurin inhibitor Immunosuppressive drugs, also known as immunosuppressive agents, immunosuppressants and antirejection medications, are drugs that inhibit or prevent activity of the immune system. Classification Immunosuppressive drugs can be classified into ...
for example increases the risk approximately 200 times, and
azathioprine Azathioprine (AZA), sold under the brand name Imuran, among others, is an immunosuppressive medication. It is used in rheumatoid arthritis, granulomatosis with polyangiitis, Crohn's disease, ulcerative colitis, and systemic lupus erythematosus, ...
about 60 times. * Deliberate exposure of sensitive skin not normally exposed to sunlight during alternative wellness behaviors such as
perineum sunning The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), includin ...
.


Pathophysiology

A malignant epithelial tumor that primarily originates in the epidermis, in squamous mucosa or in areas of squamous metaplasia is referred to as a squamous-cell carcinoma. Macroscopically, the tumor is often elevated, fungating, or may be ulcerated with irregular borders. Microscopically, tumor cells destroy the basement membrane and form sheets or compact masses which invade the subjacent connective tissue (dermis). In well differentiated carcinomas, tumor cells are pleomorphic/atypical, but resembling normal keratinocytes from prickle layer (large, polygonal, with abundant
eosinophilic Eosinophilic (Greek suffix -phil-, meaning ''loves eosin'') is the staining of tissues, cells, or organelles after they have been washed with eosin, a dye. Eosin is an acidic dye for staining cell cytoplasm, collagen, and muscle fibers. ''E ...
(pink) cytoplasm and central nucleus). Their disposal tends to be similar to that of normal epidermis: immature/basal cells at the periphery, becoming more mature to the centre of the tumor masses. Tumor cells transform into
keratinized Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, h ...
squamous cells and form round nodules with concentric, laminated layers, called "cell nests" or "epithelial/keratinous pearls". The surrounding stroma is reduced and contains inflammatory infiltrate (lymphocytes). Poorly differentiated squamous carcinomas contain more pleomorphic cells and no
keratinization Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...
. A molecular factor involved in the disease process is mutation in gene
PTCH1 Protein patched homolog 1 is a protein that is the member of the patched family and in humans is encoded by the ''PTCH1'' gene. Function PTCH1 is a member of the patched gene family and is the receptor for sonic hedgehog, a secreted molecule ...
that plays an important role in the Sonic hedgehog signaling pathway.


Diagnosis

Diagnosis is 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 dise ...
and histopathological examination. Non-invasive skin cancer detection methods include photography, dermatoscopy, sonography,
confocal microscopy Confocal microscopy, most frequently confocal laser scanning microscopy (CLSM) or laser confocal scanning microscopy (LCSM), is an optical imaging technique for increasing optical resolution and contrast of a micrograph by means of using a s ...
, Raman spectroscopy, fluorescence spectroscopy, terahertz spectroscopy, optical coherence tomography, the multispectral imaging technique, thermography, electrical bio-impedance, tape stripping and computer-aided analysis. Dermatoscopy may be useful in diagnosing basal cell carcinoma in addition to skin inspection. There is insufficient evidence that optical coherence tomography (OCT) is useful in diagnosing melanoma or squamous cell carcinoma. OCT may have a role in diagnosing basal cell carcinoma but more data is needed to support this. Computer-assisted diagnosis devices have been developed that analyze images from a
dermatoscope Dermatoscopy also known as dermoscopy or epiluminescence microscopy, is the examination of skin lesions with a dermatoscope. It is a tool similar to a camera to allow for inspection of skin lesions unobstructed by skin surface reflections. The d ...
or spectroscopy and can be used by a diagnostician to aid in the detection of skin cancer. CAD systems have been found to be highly sensitive in the detection of melanoma, but have a high false-positive rate. There is not yet enough evidence to recommend CAD as compared to traditional diagnostic methods.
High-frequency ultrasound Preclinical imaging is the visualization of living animals for research purposes, such as drug development. Imaging modalities have long been crucial to the researcher in observing changes, either at the organ, tissue, cell, or molecular level, i ...
(HFUS) is of unclear usefulness in the diagnosis of skin cancer. There is insufficient evidence for reflectance confocal microscopy to diagnose basal cell or squamous cell carcinoma or any other skin cancers.


Prevention

Sunscreen is effective and thus recommended to prevent melanoma and squamous-cell carcinoma. There is little evidence that it is effective in preventing basal-cell carcinoma. Other advice to reduce rates of skin cancer includes avoiding sunburn, wearing protective clothing, sunglasses and hats, and attempting to avoid sun exposure or periods of peak exposure. The
U.S. Preventive Services Task Force The United States Preventive Services Task Force (USPSTF) is "an independent panel of experts in primary care and prevention that systematically reviews the evidence of effectiveness and develops recommendations for clinical preventive services". ...
recommends that people between 9 and 25 years of age be advised to avoid ultraviolet light. The risk of developing skin cancer can be reduced through a number of measures including decreasing
indoor tanning Indoor tanning involves using a device that emits ultraviolet radiation to produce a cosmetic tan. Typically found in tanning salons, gyms, spas, hotels, and sporting facilities, and less often in private residences, the most common device is a ...
and mid-day sun exposure, increasing the use of sunscreen, and avoiding the use of
tobacco products Tobacco is the agricultural product of the leaves of plants in the genus ''Nicotiana'', commonly termed ''tobacco plants''. All species of ''Nicotiana'' contain the addictive drug nicotine—a psychostimulant alkaloid found in all parts of the ...
. The reason it is important to limit sun exposure and to avoid tanning beds is because they both involve UV light. UV light is known to damage skin cells by mutating the DNA in it. The mutated DNA can cause tumors and other growths to form on the skin. Further, there are other risk factors beside just UV exposure. Fair skin, prolonged history of sunburns, moles, and family history of skin cancer are just a few. There is insufficient evidence either for or against screening for skin cancers.
Vitamin supplements A vitamin is an organic molecule (or a set of molecules closely related chemically, i.e. vitamers) that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism. Essential nutrie ...
and antioxidant supplements have not been found to have an effect in prevention. Evidence for reducing melanoma risk from dietary measures is tentative, with some supportive epidemiological evidence, but no clinical trials.
Zinc oxide Zinc oxide is an inorganic compound with the formula . It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cemen ...
and
titanium oxide Titanium oxide may refer to: * Titanium dioxide (titanium(IV) oxide), TiO2 * Titanium(II) oxide (titanium monoxide), TiO, a non-stoichiometric oxide * Titanium(III) oxide (dititanium trioxide), Ti2O3 * Ti3O * Ti2O * δ-TiOx (x= 0.68–0.75) * T ...
are often used in sunscreen to provide broad protection from UVA and UVB ranges. Eating certain foods may decrease the risk of sunburns but this is much less than the protection provided by sunscreen. A meta-analysis of skin cancer prevention in high risk individuals found evidence that topical application of T4N5 liposome lotion reduced the rate of appearance of basal cell carcinomas in people with
xeroderma pigmentosum Xeroderma pigmentosum (XP) is a genetic disorder in which there is a decreased ability to repair DNA damage such as that caused by ultraviolet (UV) light. Symptoms may include a severe sunburn after only a few minutes in the sun, freckling in su ...
, and that
acitretin Acitretin (trade names Soriatane and Neotigason) is a second-generation retinoid. It is taken orally, and is typically used for psoriasis. Acitretin is an oral retinoid used in the treatment of severe resistant psoriasis. Because of the potential ...
taken by mouth may have a skin protective benefit in people following
kidney transplant Kidney transplant or renal transplant is the organ transplant of a kidney into a patient with end-stage kidney disease (ESRD). Kidney transplant is typically classified as deceased-donor (formerly known as cadaveric) or living-donor transplantati ...
. A research published in January 2022 by the Oregon State University College of Pharmacy showed that a vaccine that stimulates the production of a protein critical to the skin's antioxidant network could reinforce people's defenses against skin cancer.


Treatment

Treatment is dependent on the specific type of cancer, location of the cancer, age of the person, and whether the cancer is primary or a recurrence. For a small
basal-cell cancer Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer. It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it. It may also present as a raise ...
in a young person, the treatment with the best cure rate (
Mohs surgery Mohs surgery, developed in 1938 by a general surgeon, Frederic E. Mohs, is microscopically controlled surgery used to treat both common and rare types of skin cancer. During the surgery, after each removal of tissue and while the patient waits, ...
or
CCPDMA Complete circumferential peripheral and deep margin assessment (CCPDMA) is the preferred method for the removal of certain cancers, especially skin cancers. There are two forms of CCPDMA surgery: Mohs surgery and surgical excision coupled with mar ...
) might be indicated. In the case of an elderly frail man with multiple complicating medical problems, a difficult to excise basal-cell cancer of the nose might warrant radiation therapy (slightly lower cure rate) or no treatment at all. Topical chemotherapy might be indicated for large superficial basal-cell carcinoma for good cosmetic outcome, whereas it might be inadequate for invasive nodular
basal-cell carcinoma Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer. It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it. It may also present as a raise ...
or invasive
squamous-cell carcinoma Squamous-cell carcinomas (SCCs), also known as epidermoid carcinomas, comprise a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on th ...
. In general, melanoma is poorly responsive to radiation or chemotherapy. For low-risk disease, radiation therapy (
external beam radiotherapy External beam radiotherapy (EBRT) is the most common form of radiotherapy (radiation therapy). The patient sits or lies on a couch and an external source of ionizing radiation is pointed at a particular part of the body. In contrast to brachyt ...
or
brachytherapy Brachytherapy is a form of radiation therapy where a sealed radiation source is placed inside or next to the area requiring treatment. ''Brachy'' is Greek for short. Brachytherapy is commonly used as an effective treatment for cervical, prost ...
), topical chemotherapy (
imiquimod Imiquimod, sold under the brand name Aldara among others, is a medication that acts as an immune response modifier that is used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis. Scientists at 3M's pharmaceuticals ...
or 5-fluorouracil) and cryotherapy (freezing the cancer off) can provide adequate control of the disease; all of them, however, may have lower overall cure rates than certain type of surgery. Other modalities of treatment such as photodynamic therapy,
epidermal radioisotope therapy The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...
, topical chemotherapy,
electrodesiccation and curettage Electrodesiccation and curettage (EDC, ED & C, or ED+C) is a medical procedure commonly performed by dermatologists, surgeons and general practitioners for the treatment of basal cell cancers and squamous cell cancers of the skin. It provides ...
can be found in the discussions of
basal-cell carcinoma Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer. It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it. It may also present as a raise ...
and
squamous-cell carcinoma Squamous-cell carcinomas (SCCs), also known as epidermoid carcinomas, comprise a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on th ...
. Mohs' micrographic surgery (
Mohs surgery Mohs surgery, developed in 1938 by a general surgeon, Frederic E. Mohs, is microscopically controlled surgery used to treat both common and rare types of skin cancer. During the surgery, after each removal of tissue and while the patient waits, ...
) is a technique used to remove the cancer with the least amount of surrounding tissue and the edges are checked immediately to see if tumor is found. This provides the opportunity to remove the least amount of tissue and provide the best cosmetically favorable results. This is especially important for areas where excess skin is limited, such as the face. Cure rates are equivalent to wide excision. Special training is required to perform this technique. An alternative method is
CCPDMA Complete circumferential peripheral and deep margin assessment (CCPDMA) is the preferred method for the removal of certain cancers, especially skin cancers. There are two forms of CCPDMA surgery: Mohs surgery and surgical excision coupled with mar ...
and can be performed by a pathologist not familiar with
Mohs surgery Mohs surgery, developed in 1938 by a general surgeon, Frederic E. Mohs, is microscopically controlled surgery used to treat both common and rare types of skin cancer. During the surgery, after each removal of tissue and while the patient waits, ...
. In the case of disease that has spread (metastasized), further surgical procedures or
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 ...
may be required. Treatments for metastatic melanoma include biologic immunotherapy agents
ipilimumab Ipilimumab, sold under the brand name Yervoy, is a monoclonal antibody medication that works to activate the immune system by targeting CTLA-4, a protein receptor that downregulates the immune system. Cytotoxic T lymphocytes (CTLs) can recogniz ...
,
pembrolizumab Pembrolizumab, sold under the brand name Keytruda, is a humanized antibody used in cancer immunotherapy that treats melanoma, lung cancer, head and neck cancer, Hodgkin lymphoma, stomach cancer, cervical cancer, and certain types of breast canc ...
,
nivolumab Nivolumab, sold under the brand name Opdivo, is a medication used to treat a number of types of cancer. This includes melanoma, lung cancer, malignant pleural mesothelioma, renal cell carcinoma, Hodgkin lymphoma, head and neck cancer, urotheli ...
, cemiplimab;
BRAF inhibitor BRAF is a human gene that encodes a protein called B-Raf. The gene is also referred to as proto-oncogene B-Raf and v-Raf murine sarcoma viral oncogene homolog B, while the protein is more formally known as serine/threonine-protein kinase B-Raf. T ...
s, such as
vemurafenib Vemurafenib ( INN, marketed as Zelboraf) is an inhibitor of the B-Raf enzyme developed by Plexxikon (now part of Daiichi-Sankyo) and Genentech for the treatment of late-stage melanoma.; The name "vemurafenib" comes from V600E mutated BRAF in ...
and
dabrafenib Dabrafenib, sold under the brand name Tafinlar & Rafinlar ( both by Novartis) among others, is a medication for the treatment of cancers associated with a mutated version of the gene BRAF. Dabrafenib acts as an inhibitor of the associated enzyme ...
; and a
MEK inhibitor A MEK inhibitor is a chemical or drug that inhibits the mitogen-activated protein kinase kinase enzymes MEK1 and/or MEK2. They can be used to affect the MAPK/ERK pathway which is often overactive in some cancers. (See MAPK/ERK pathway#Clinical sign ...
trametinib Trametinib, sold under the brand name Mekinist among others, is an anticancer medication used for the treatment of melanoma. It is a MEK inhibitor drug with anti-cancer activity. It inhibits MEK1 and MEK2. Trametinib had good results for metas ...
.


Reconstruction

Currently, surgical excision is the most common form of treatment for skin cancers. The goal of reconstructive surgery is the restoration of normal appearance and function. The choice of technique in reconstruction is dictated by the size and location of the defect. Excision and reconstruction of facial skin cancers are generally more challenging due to the presence of highly visible and functional anatomic structures in the face. When skin defects are small in size, most can be repaired with simple repair where skin edges are approximated and closed with sutures. This will result in a linear scar. If the repair is made along a natural skin fold or wrinkle line, the scar will be hardly visible. Larger defects may require repair with a skin graft, local skin flap, pedicled skin flap, or a microvascular free flap. Skin grafts and local skin flaps are by far more common than the other listed choices. Skin grafting is patching of a defect with skin that is removed from another site in the body. The skin graft is sutured to the edges of the defect, and a bolster dressing is placed atop the graft for seven to ten days, to immobilize the graft as it heals in place. There are two forms of skin grafting: split thickness and full thickness. In a split thickness skin graft, a shaver is used to shave a layer of skin from the abdomen or thigh. The donor site regenerates skin and heals over a period of two weeks. In a full thickness skin graft, a segment of skin is totally removed and the donor site needs to be sutured closed. Split thickness grafts can be used to repair larger defects, but the grafts are inferior in their cosmetic appearance. Full thickness skin grafts are more acceptable cosmetically. However, full thickness grafts can only be used for small or moderate sized defects. Local skin flaps are a method of closing defects with tissue that closely matches the defect in color and quality. Skin from the periphery of the defect site is mobilized and repositioned to fill the deficit. Various forms of local flaps can be designed to minimize disruption to surrounding tissues and maximize cosmetic outcome of the reconstruction. Pedicled skin flaps are a method of transferring skin with an intact blood supply from a nearby region of the body. An example of such reconstruction is a pedicled forehead flap for the repair of a large nasal skin defect. Once the flap develops a source of blood supply form its new bed, the vascular pedicle can be detached.


Prognosis

The mortality rate of basal-cell and squamous-cell carcinoma is around 0.3%, causing 2000 deaths per year in the US. In comparison, the mortality rate of melanoma is 15–20% and it causes 6500 deaths per year. Even though it is much less common, malignant melanoma is responsible for 75% of all skin cancer-related deaths. The survival rate for people with melanoma depends upon when they start treatment. The cure rate is very high when melanoma is detected in early stages, when it can easily be removed surgically. The prognosis is less favorable if the melanoma has spread to other parts of the
body Body may refer to: In science * Physical body, an object in physics that represents a large amount, has mass or takes up space * Body (biology), the physical material of an organism * Body plan, the physical features shared by a group of anima ...
. As of 2003 the overall five-year cure rate with Mohs' micrographic surgery was around 95 percent for recurrent basal cell carcinoma.
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
and
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
exhibit one of the highest rates of skin cancer incidence in the world, almost four times the rates registered in the United States, the UK and
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
. Around 434,000 people receive treatment for non-melanoma skin cancers and 10,300 are treated for melanoma. Melanoma is the most common type of cancer in people between 15 and 44 years in both countries. The incidence of skin cancer has been increasing. The incidence of melanoma among
Auckland Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The List of New Zealand urban areas by population, most populous urban area in the country and the List of cities in Oceania by po ...
residents of European descent in 1995 was 77.7 cases per 100,000 people per year, and was predicted to increase in the 21st century because of "the effect of local stratospheric ozone depletion and the time lag from sun exposure to melanoma development."


Epidemiology

Skin cancers result in 80,000 deaths a year as of 2010, 49,000 of which are due to melanoma and 31,000 of which are due to non-melanoma skin cancers. This is up from 51,000 in 1990. More than 3.5 million cases of skin cancer are diagnosed annually in the United States, which makes it the most common form of cancer in that country. One in five Americans will develop skin cancer at some point of their lives. The most common form of skin cancer is basal-cell carcinoma, followed by squamous cell carcinoma. Unlike for other cancers, there exists no basal and squamous cell skin cancers
registry Registry may refer to: Computing * Container registry, an operating-system-level virtualization registry * Domain name registry, a database of top-level internet domain names * Local Internet registry * Metadata registry, information system for re ...
in the United States.


Melanoma

In the US in 2008, 59,695 people were diagnosed with melanoma, and 8,623 people died from it.CDC – Skin Cancer Statistics
In Australia more than 12,500 new cases of melanoma are reported each year, out of which more than 1,500 die from the disease. Australia has the highest per capita incidence of melanoma in the world. Although the rates of many cancers in the United States is falling, the incidence of melanoma keeps growing, with approximately 68,729 melanomas diagnosed in 2004 according to reports of the
National Cancer Institute The National Cancer Institute (NCI) coordinates the United States National Cancer Program and is part of the National Institutes of Health (NIH), which is one of eleven agencies that are part of the U.S. Department of Health and Human Services. ...
. Melanoma is the fifth most common cancer in the UK (around 13,300 people were diagnosed with melanoma in 2011), and the disease accounts for 1% all cancer deaths (around 2,100 people died in 2012).


Non-melanoma

Approximately 2,000 people die from basal or squamous cell skin cancers (non-melanoma skin cancers) in the United States each year. The rate has dropped in recent years. Most of the deaths happen to people who are elderly and might not have seen a doctor until the cancer had spread; and people with immune system disorders.


References


External links

*
Skin cancer procedures: text, images and videos
{{DEFAULTSORT:Skin Cancer Integumentary neoplasia Sun tanning Wikipedia medicine articles ready to translate Medical mnemonics