Melanoma is a type of skin cancer that forms in skin cells called melanocytes (cells that make melanin, the pigment that gives skin its color). It sometimes develops from a nevus or mole that is already present but isn’t cancerous. Cutaneous melanomas, the most common type, can occur anywhere along the skin but are most commonly found on the chest or back in men and on the legs in women. Melanomas can also develop in mucous membranes (lining the mouth, gastrointestinal tract, or other areas of the body) or in the retina of the eye.
The average person in the United States has a lifetime risk for melanoma that is 2%. Most cases of melanoma are diagnosed at older ages, but melanoma is one of the most common cancers diagnosed in people under the age of 30.Some hereditary cancer syndromes cause an increased risk for melanoma.
General Risk Factors
- A family history of melanoma
- Moles – most moles will not develop into melanoma, but people with many moles, especially dysplastic nevi (moles with irregular color and shape), have a higher risk for melanoma
- Fair skin, freckling, and light hair-individuals who burn easily are at increased risk
- Personal history of a previous skin cancer
- A history of one or more blistering sunburns
- A weakened immune system (this could be due to taking medications following an organ transplant surgery)
- Ultraviolet (UV) light exposure – sunlight is a main source of UV rays but tanning beds may also cause significant UV light exposure
- Living closer to the equator or at higher elevations
As with the vast majority of cancers, there is no confirmed way to completely prevent the development of melanoma. Avoiding or limiting sun exposure, avoiding tanning beds, wearing sun-protective clothing (hat, clothes made of UV-protected fabric, sunglasses), wearing a broad spectrum sunscreen (with a sun protective factor (SPF) of at least 30 and reapplying as directions indicate), and regular skin checks can all help reduce the risk for melanoma.
Symptoms and Screening Methods
When evaluating moles for warning signs of melanoma, it can be helpful to use the “ABCDE” rule. Check for asymmetry (the shape of half of a mole does not match the other half), border (ragged, notched, uneven, or blurred border), color, and diameter. The “E” stands for evolving. Look for changes in any of the previously mentioned features of a mole. Also look for changes in texture, or the way a mole feels. These symptoms can appear in an existing mole or may be present in a new abnormal-looking mole.
Skin self-exams and skin exams by health care professionals can help detect melanoma. Self-exams are best performed in a well-lit room with access to a full-length mirror. A hand-held mirror or a family member can help with the viewing of hard to see areas of the body. Self-exams can be performed as much as once a month so that you can notice any new moles or changes to existing moles. Any suspicious moles should be evaluated by your doctor and/or a dermatologist (a doctor specializing in skin problems). Regular skin exams performed by a health care professional are important for people considered to be at a higher risk for melanoma due to any of the risk factors above, including a hereditary cancer syndrome. Biopsies (tissue samples) of moles can be taken by a doctor if a mole needs to be further evaluated.
If melanoma is diagnosed following a biopsy, treatment will depend on the stage of the cancer (how far the cancer has grown or spread). Treatment can include some combination of surgery, chemotherapy and radiation therapy or could also include biologic therapy (a treatment that uses a patient’s immune system to fight cancer) or targeted therapy (a treatment that uses drugs or other agents to attack cancer cells).