Skin cancer is the most common form of cancer in the United States, occurring in over 3.5 million people each year. Three of the most common types of skin cancer are squamous cell carcinoma, basal cell carcinoma, and melanoma. Of these, the least common, but most serious is melanoma.
What is melanoma?—Melanoma is a cancer of the pigment producing cells (melanocytes) of the skin. The great majority of melanomas can be attributed to exposure to ultraviolet (UV) radiation from the sun. Melanoma begins on the surface of the skin but over time can extend deeper and in some cases, even spread throughout the body.
Who gets melanoma?—The factors that increase your risk of developing melanoma include:
- Fair skin
- Severe or multiple sunburns
- A close relative, e.g. parent, child or sibling, who has had a melanoma
- Unusual (atypical) moles
- More than 50 moles
- Weakened immune system, e.g. HIV/AIDS or organ transplant
The National Cancer Institute has developed a Melanoma Risk Assessment Tool to assess your personal risk of developing melanoma.
Recognizing melanoma—Signs indicating that a skin lesion is melanoma include a new pigmented area on the skin, or a change in size, shape or color of an existing mole. The ABCDE rule is another way to recognize melanomas:
- Asymmetry: A mole that has an irregular shape, or the shape of one half does not match the other half.
- Border: The edges are irregular, blurred, rough, or notched in outline.
- Color: Most moles are evenly colored, e.g. brown, black, or tan. Changes in the shade or distribution of color throughout the mole can signal melanoma.
- Diameter: Moles larger than ¼ inch (6 mm, the size of a pencil eraser) across are suspicious.
- Evolving: The mole has changed over the past few weeks or months
Treatment of Melanoma—Melanoma is the most serious type of skin cancer. Early recognition and treatment leads to better outcomes. Treatment in almost all cases begins with surgical excision, typically including a margin of apparently normal skin to insure that the lesion is removed entirely. Beyond surgical excision, treatment depends on the “stage” or extent of involvement of the cancer. In the more advanced stages, the tumor can invade deeply, spread to lymph nodes, or even metastasize to other areas of the body. For the least serious type of melanoma skin cancers (Stage 1), wide surgical excision may be all the treatment that is necessary. The outcome of treatment in these cases may be enhanced by using the Mohs technique. For higher stages, treatment may include chemotherapy, radiation therapy, immunotherapy, and targeted therapy. An example of targeted therapy involves the use of a drug, e.g. vemurafenib (Zelboraf) that attacks certain proteins in the tumor, leading to its destruction. While most Stage 1 melanoma patients can be cured, the 5-year survival rate for a Stage 4 melanoma patient is only about 15% to 20%.
Reducing the risk of developing melanoma—The development of most types of skin cancer is directly related to damage from exposure to ultraviolet (UV) radiation from the sun. Here are some suggestions for minimizing exposure to these harmful rays:
- Limit your exposure to ultraviolet (UV) rays. Avoid being in the sun during the peak hours for UV exposure between 10 AM and 4PM. Don’t forget that snow and water can concentrate the sun’s rays and increase the risk of burning.
- If sun exposure is unavoidable, use a broad spectrum sunscreen that is effective against UVA and UVB radiation with a SPF of 30 or higher. This may be required year round, not just in the summer.
- For extra protection wear long sleeves and long pants and a wide-brimmed hat. Wraparound sunglasses help to protect the skin around the eyes.
- Avoid tanning beds or lights. Despite claims of tanning bed companies and booths, the radiation (predominantly UVA) used in tanning lights increases the risk of developing skin cancer. Exposure to tanning lights has been linked with an increased risk of melanoma, especially if it is started before a person is 30.
- Pay attention to your own skin. Any suspicious lesion should be brought to the attention of your primary care doctor or a dermatologist. Melanomas can develop even in areas of the skin not exposed to the sun.
Regular examination of the skin, by a physician or by self-examination, is the key to identifying skin cancers in their earliest stages. With summer approaching and many people spending more time in the outdoors, particular attention to should be given to avoiding sun exposure in order to reduce the risk of developing melanoma or other skin cancers.