What is skin cancer?
![There are three types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and melanoma.](https://images.medicinenet.com/images/article/main_image/skin-cancer-1.jpg?output-quality=75)
Most skin cancers are locally destructive cancerous (malignant) growth of the skin. They originate from the cells of the epidermis, the superficial layer of the skin. Unlike cutaneous malignant melanoma, the vast majority of these sorts of skin cancers rarely spread to other parts of the body (metastasize) and become life-threatening.
There are three major types of skin cancer:
- basal cell carcinoma (the most common),
- squamous cell carcinoma (the second most common), which originate from skin cells, and
- melanoma, which originates from the pigment-producing skin cells (melanocytes) but is less common, though more dangerous, than the first two varieties.
Other rare forms of skin cancer include lymphomas, Merkel cell cancers, and cancers of other tissue in the skin, including sarcomas as well as hair and sweat gland tumors. In this article, we will only be reviewing the most common forms of cancers, basal cell carcinoma, and squamous cell carcinoma.
What are the different types of skin cancer?
There are several different types of skin cancers:
- Basal cell carcinoma is the most common cancer in humans. Over 1 million new cases of basal cell carcinoma are diagnosed in the U.S. each year. There are several different types of basal cell carcinoma, including the superficial type, the least worrisome variety; the nodular type, the most common; and the morpheaform, the most challenging to treat because the tumors often grow into the surrounding tissue (infiltrate) without a well-defined border.
- Squamous cell carcinoma accounts for about 20% of all skin cancers but is more common in immunosuppressed people. In most instances, its biological behavior is much like basal cell carcinoma with a small but significant chance of distant spread.
Less common skin cancers include:
- Melanoma
- Merkel cell carcinoma
- Atypical fibroxanthoma
- Cutaneous lymphoma
- Dermatofibrosarcoma
What causes skin cancer?
Except in rare instances, most skin cancers arise from DNA mutations induced by ultraviolet light affecting cells of the epidermis. Many of these early cancers seem to be controlled by natural immune surveillance, which when compromised, may permit the development of masses of malignant cells that begin to grow into tumors.
Is skin cancer hereditary?
Since most skin cancers are caused by ultraviolet light exposure, skin cancers are generally not considered to be inherited. But the fact that skin cancer is much more common among poorly pigmented individuals and that skin color is inherited does support the proposition that genetics is very important.
Some very rare genetic syndromes result in an increased number of skin cancers in those affected.
What are the risk factors for skin cancer?
The most common risk factors for skin cancer are as follows.
- Ultraviolet light exposure, either from the sun or from tanning beds. Fair-skinned individuals, with hazel or blue eyes, and people with blond or red hair are particularly vulnerable. The problem is worse in areas of high elevation or near the equator where sunlight exposure is more intense.
- A chronically suppressed immune system (immunosuppression) from underlying diseases such as HIV/AIDS infection or cancer, or some medications such as prednisone or chemotherapy
- Exposure to ionizing radiation (X-rays) or chemicals known to predispose to cancer such as arsenic
- Certain types of sexually acquired wart virus infections
- People who have a history of one skin cancer have a 20% chance of developing second skin cancer in the next two years.
- Elderly patients have more skin cancers.
![](https://images.medicinenet.com/images/slideshow/summerskin_rm_collage_of_precancerous_skin_growths_s17.jpg)
IMAGES
Skin Cancer 0 See ImagesWhat are the signs and symptoms of skin cancer?
Most basal cell carcinomas have few if any symptoms. Squamous cell carcinomas may be painful. Both forms of skin cancer may appear as a sore that bleeds, oozes, crusts, or otherwise will not heal. They begin as a slowly growing bump on the skin that may bleed after minor trauma. Both kinds of skin cancers may have raised edges and central ulceration.
Signs and symptoms of basal cell carcinomas include:
- The appearance of a shiny pink, red, pearly, or translucent bump
- Pink skin growths or lesions with raised borders that are crusted in the center
- A raised reddish patch of skin that may crust or itch, but is usually not painful
- A white, yellow, or waxy area with a poorly defined border that may resemble a scar
Signs and symptoms of squamous cell carcinomas include:
- Persistent, scaly red patches with irregular borders that may bleed easily
- An open sore that does not go away for weeks
- A raised growth with a rough surface that is indented in the middle
- A wart-like growth
Actinic keratoses (AK), also called solar keratoses, are scaly, crusty lesions caused by damage from ultraviolet light, often in the facial area, scalp, and backs of the hands. These are considered precancers because if untreated, up to 10% of actinic keratoses may develop into squamous cell carcinomas.
When is a mole dangerous or high risk for becoming a skin cancer?
Moles are almost always harmless and only very rarely turn into skin cancer. If a mole becomes cancerous, it would be melanoma.
There is a precancerous stage, called a dysplastic nevus, which is somewhat more irregular than a normal mole.
An early sign of melanoma is noticing a difference in a mole:
- asymmetry,
- irregular border,
- color changes,
- increasing diameter, or
- other evolving changes may signify a mole is a melanoma.
Moles never become squamous cell carcinomas or basal cell carcinomas.
What are the most common sites where skin cancer develops?
Skin cancers typically arise in areas of the skin exposed to the sun repeatedly over many years such as on the face and nose, ears, back of the neck, and the bald area of the scalp.
Less commonly, these tumors may appear at sites with only limited sun exposure such as the back, chest, or extremities. However, skin cancer may occur anywhere on the skin.
Health News
- STD Specialists Warn of Shortage of Vital Syphilis Drug
- Immediate Body Contact With Parents Helps Preemie Newborns Thrive
- Identical Twins Study Shows Vegan Diets Helping the Heart
- Timing of Menopause Could Affect a Woman's Muscle Loss
- One Food Could Boost Health of Colon Cancer Survivors
More Health News »
What kinds of doctors treat skin cancer?
The main type of doctor who will treat skin cancer is a dermatologist. Your primary care physician or internist may first notice a sign of skin cancer but will refer you to a dermatologist for further testing and treatment.
You may also see an oncologist, which is a cancer specialist.
If you have surgical removal of a tumor, depending on how much skin is removed, you may see a plastic or reconstructive surgeon after the tumor removal to help restore the appearance of the skin, especially on the face.
How do physicians diagnose skin cancer?
A skin examination by a dermatologist is the way to get a definitive diagnosis of skin cancer. In many cases, appearance alone is sufficient to make the diagnosis.
A skin biopsy is usually used to confirm a suspicion of skin cancer. This is performed by numbing the area under the tumor with a local anesthetic such as lidocaine. A small portion of the tumor is sliced away and sent for examination by a pathologist, who looks at the tissue under a microscope and renders a diagnosis based on the characteristics of the tumor.
What is the staging for skin cancer?
There is no specific staging system for basal cell carcinoma.
- If the tumor is wider than 2 cm (about ¾ inch diameter), it is probably a more serious tumor.
- Basal cell carcinomas of the ears, nose, and eyelid may also be of more concern, regardless of the size.
There is a staging system for squamous cell carcinoma.
- Large tumors that are thicker than 2 mm, invade the nerve structures of the skin, occur on the ear, and have certain worrisome characteristics under the microscope are of more concern.
- If the tumor metastasizes to a site at some distance from the primary tumor, the cancer is likely to be a dangerous tumor.
What is the treatment for skin cancer?
There are several effective means of treating skin cancer. The choice of therapy depends on the location and size of the tumor, the microscopic characteristics of the cancer, and the general health of the patient.
- Topical medications: In the case of superficial basal cell carcinomas, some creams, gels, and solutions can be used, including imiquimod (Aldara), which works by stimulating the body's immune system causing it to produce interferon which attacks cancer, and fluorouracil (5-FU), a chemotherapy drug. Some patients do not experience any side effects from these topical treatments, but others may have redness, inflammation, and irritation. A drawback of topical medications is that there is no tissue available to examine to determine if a tumor is removed completely.
- Destruction by electrodesiccation and curettage (EDC): The tumor area is numbed with a local anesthetic and is repeatedly scraped with a sharp instrument (curette), and the edge is then cauterized with an electric needle. The advantage of this method is that it is fast, easy, and relatively inexpensive. The disadvantages are that the scar is often somewhat unsightly, and the recurrence rate is as high as 15%.
- Surgical excision: The area around the tumor is numbed with a local anesthetic. A football-shaped portion of tissue including the tumor is then removed and then the wound edges are closed with sutures. For very big tumors, skin grafts or flaps are needed to close the defect. The advantages of this form of treatment are that there is a greater than 90% cure rate, the surgical specimen can be examined to be sure that the whole tumor is successfully removed, and the scar produced is usually more cosmetically acceptable than that of the EDC procedure. It is a more complicated procedure and is more expensive than EDC.
- Mohs micrographic surgery: The site is locally anesthetized and the surgeon removes the visible tumor with a small margin of normal tissue. The tissue is immediately evaluated under a microscope and areas that demonstrate residual microscopic tumor involvement are re-excised and the margins are re-examined. This cycle continues until no further tumor is seen. This more complicated and expensive option is the treatment of choice for tumors where normal tissue preservation is vital, where the tumor margins are poorly defined, in tumors that have been previously treated and have recurred, and in certain high-risk tumors.
- Radiation therapy: Ten to fifteen treatment sessions deliver a high dose of radiation to the tumor and a small surrounding skin area. This form of treatment is useful for those who are not candidates for any surgical procedure. The advantage of radiation therapy is that there is no cutting involved. The disadvantages of this expensive alternative are that the treated area cannot be tested to be sure the whole tumor is gone and radiation scars look worse over time. It is, for this reason, it is usually reserved for elderly patients.
Other types of treatments for skin cancers include:
- Cryosurgery where tissue is destroyed by freezing
- Photodynamic therapy (PDT) in which medication and blue light are used to destroy the cancerous tissue
- Laser surgery to vaporize (ablate) the skin's top layer and destroy lesions
- Oral medications vismodegib (Erivedge) and sonidegib (Odomzo)
Subscribe to MedicineNet's Cancer Report Newsletter
By clicking "Submit," I agree to the MedicineNet Terms and Conditions and Privacy Policy. I also agree to receive emails from MedicineNet and I understand that I may opt out of MedicineNet subscriptions at any time.
What is the prognosis and survival rate for skin cancer?
The prognosis for nonmelanoma skin cancer is generally excellent.
- Both basal cell carcinoma and squamous cell carcinoma are highly curable.
- There are virtually no deaths from basal cell carcinoma and only rare deaths with squamous cell carcinoma skin cancers, mostly in immunosuppressed individuals.
- Depending on the method of treatment and the location and type of skin cancer, the likelihood of a recurrence of a previously treated skin cancer is as low as 1% to 2% for Mohs surgery and up to 10% to 15% for destruction by electrodesiccation and curettage.
Early detection of skin cancers can lead to better outcomes. Know your skin and if you have any moles or spots that are suspect, see a dermatologist for a skin cancer screening. Awareness is key in identifying and treating skin cancers early.
Is it possible to prevent skin cancer?
Many skin cancers can be prevented by avoiding triggers that cause tumors to develop.
Prevention strategies for skin cancer include:
- protection from the sun by the use of sunscreens,
- protective clothing, and
- avoidance of the sun during the peak hours of 9 a.m. to 3 p.m.
- Parents should ensure children are protected from the sun.
- Do not use tanning beds, which are a major cause of excess ultraviolet light exposure and a significant risk factor for skin cancer.
The American Academy of Dermatology (AAD) has noted a dramatic rise in the numbers and cost of skin cancer. Furthermore, there has been an increase in the total number of skin cancers, and breakthrough treatments for melanoma, although expensive, comprise only a small portion of the total cost of skin cancer treatment. Most skin cancers are treated cost-efficiently by dermatologists in an office setting.
Sunscreen use and vitamin D
A major source of vitamin D comes from sunlight exposure, which leads to the production of the vitamin in the skin. Some argue sunscreens block out so much of the sun's rays that inadequate vitamin D synthesis results. Very few people actually apply sunscreen to every inch of their exposed skin, so vitamin D synthesis does occur. There is no reason not to use sunscreens because of a fear of low vitamin D. If there is a concern, vitamin D can be obtained by eating leafy vegetables or taking an oral multivitamin supplement.
From ![WebMD Logo](https://images.medicinenet.com/images/promo/logo_webmd.gif)
Skin Protection Resources
Featured Centers
Health Solutions From Our Sponsors
Health Solutions From Our Sponsors
American Society of Clinical Oncology. "Skin Cancer (Non-Melanoma): Symptoms and Signs." June 2015.
Kauvar, Arielle N.B., et al. "Consensus for Nonmelanoma Skin Cancer Treatment: Basal Cell Carcinoma, Including a Cost Analysis of Treatment Methods." Dermatol Surg 41 (2015): 550-571.
Bichakjian, Christopher, et al. "Guidelines of Care for the Management of Basal Cell Carcinoma." J Am Acad Dermatol 2017: 1-19.
Rogers, Howard W., Martin A. Weinstock, Steven R. Feldman, and Brett M. ColdIron. "Incidence Estimate of Nonmelanoma Skin Cancer (Keratinocyte Carcinomas) in the US Population, 2012." JAMA Dermatol 151.10 (2015): 1081-1086.
Skin Cancer Foundation. "Actinic Keratoses (AK)." 2016.
Skin Cancer Foundation. "Basal Cell Carcinoma Treatment Options." 2016.
Skin Cancer Foundation. "Do You Know Your ABCDEs?" 2016.
Top Skin Cancer Overview Related Articles
Cancer
Cancer is a disease caused by an abnormal growth of cells, also called malignancy. It is a group of 100 different diseases, and is not contagious. Cancer can be treated through chemotherapy, a treatment of drugs that destroy cancer cells.Cancer 101 Slideshow
Learn the basics about cancer including types, causes, how it spreads, symptoms and signs, stages and treatment options. Read about the common type of cancers.Cancer Quiz
Take this quiz to learn the causes of cancer. Get the facts about the causes, symptoms, and treatments for the world's most common cancers.Cryotherapy
Cryotherapy, sometimes referred to as cryosurgery, is a pain treatment procedure that uses a method of localized freezing temperatures to deaden an irritated nerve. Cryotherapy can be used to treat nerve irritation between the ribs (intercostal neuralgia), cluneal nerve entrapment, ilioinguinal neuroma, hypogastric neuromas, lateral femoral cutaneous nerve entrapment, and interdigital neuromas, nerve entrapment (pinched nerves), and neuromas.Genital Warts (HPV) Infection in Women
Genital warts is a sexually transmitted infection (STI) caused by the human papillomavirus (HPV). Warts look like raised, flesh-colored lumps. Learn about symptoms, transmission, and treatment.Itching (Pruritus)
Itching can be a common problem. Itches can be localized or generalized. There are many causes of itching including infection (jock itch, vaginal itch), disease (hyperthyroidism, liver or kidney), reactions to drugs, and skin infestations (pubic or body lice). Treatment for itching varies depending on the cause of the itch.Mohs Surgery for Skin Cancer
Mohs micrographic surgery is a method of removing skin cancers with a local anesthetic. During the procedure, small layers of skin are removed and examined under a microscope until the skin samples indicate that all the cancer has been removed.Moles Picture
Moles are growths on the skin that are usually brown or black. See a picture of Moles and learn more about the health topic.Photodynamic Therapy
Photodynamic therapy (PDT) is a procedure that treats precancerous cells, in addition to other types of cancer cells. The medical treatment does this with the help of a photosensitizing drug and a light source that activates the applied drug, destroying cancer cells. PDT is approved to treat non-small cell lung cancer, esophageal cancer, and Barrett's esophagus. It treats actinic keratosis, as well as acne, rosacea, skin cancer, sun damage, oily skin, wrinkles, warts, psoriasis, and enlarged sebaceous glands.PUVA
PUVA is an acronym. The P stands for psoralen, the U for ultra, the V for violet and the A for that portion of the solar spectrum between 290 and 320 nanometers in wavelength. PUVA was originally developed to treat psoriasis.Radiation Therapy
Radiation therapy is a cancer-fighting technique. In radiation therapy, a radiation oncologist uses high-energy rays to kill cancer cells and stop them from growing and dividing. The two types of radiation therapy are external and internal. Potential side effects of radiation therapy include:- tiredness,
- rash,
- skin redness,
- permanent pigmentation,
- scarring,
- diarrhea, and
- a reduction in white blood cells.
Skin Cancer Quiz
What causes skin cancer? Take our Skin Cancer Quiz to learn about the risks, symptoms, causes, and treatments for this common skin condition that affects millions of people worldwide.Skin Problems: Rosacea, Acne, Shingles, Covid-19 Rashes
Learn to spot and treat skin conditions commonly found in adults such as acne, Covid-19 rashes, eczema, shingles, psoriasis, rosacea, hives, cold sores, razor bumps, athlete's foot, and more dermatology details.Skin Quiz
What's that all over you? Skin, of course! Test your knowledge of your most amazing organ with the Skin Quiz!Skin Conditions Below the Waist
Skin conditions like acne, eczema, psoriasis, and allergies may produce redness and other symptoms. See your dermatologist right away if you develop itchy skin, rashes, pimples, or other skin conditions. Dermatology experts are best if you suspect skin cancer or other serious skin disease.Skin Tag
A skin tag is a small benign growth of skin that projects from the surrounding skin. Skin tags can vary in appearance (smooth, irregular, flesh colored, dark pigment, raised). Skin tags generally do not cause symptoms unless repeatedly irritated. Treatment for skin tag varies depending on the location on the body.Vitamin D Deficiency
Vitamin D deficiency has been linked with rickets, cancer, cardiovascular disease, severe asthma in children and cognitive impairment in older adults. Causes include not ingesting enough of the vitamin over time, having limited exposure to sunlight, having dark skin, and obesity. Symptoms include bone pain and muscle weakness. Treatment for vitamin D deficiency involves obtaining more vitamin D through supplements, diet, or exposure to sunlight.Signs of Cancer in Women: Symptoms You Can't Ignore
Colon and stomach cancer symptoms can surprise women but can be treated if detected early. Learn about breast cancer signs and symptoms, mammograms, tests for gynecological cancers, and other cancers, including skin cancer, lung cancer, throat cancer, and bladder cancer.