What is Melanoma?
Melanoma is a cancer that begins in the melanocytes, a certain type of skin cell. Because most melanoma cells still make melanin, melanoma tumors are often brown or black in color. Some melanomas do not make melanin and can appear pink, tan or even white.
Melanoma can occur anywhere on the skin, but they are more likely to start in certain locations. The trunk (chest and back) is the most common site in men. The legs are the most common site in women.The neck and face are other common sites.
Having a darker skin tone lowers your risk of melanoma at these more common sites, but anyone can develop melanoma on the palms of the hands, soles of the feet, and under the nails. Melanomas in these areas account for more than half of the cases in African Americans but fewer than 1 in 10 melanomas in Caucasians.
Melanomas can also form in other parts of your body including the eyes, mouth, genitals and anal area but these are much less common than melanoma of the skin.
Melanoma is much less common than basal cell and squamous cell carcinomas, but it is far more dangerous. Like basal cell and squamous cell cancers, melanoma is almost always curable in its early stages. But it is much more likely than basal or squamous cell cancer to spread to other parts of the body if not diagnosed and treated early.
Main types of melanoma
Superficial spreading melanoma accounts for 70% of melanomas. Typically asymptomatic, it occurs most often on women’s legs and men’s torsos. These lesions are usually irregular and raised with tan or brown areas. They sometimes have red, white, black, and blue spots or small blue-black nodules. Small indentations in the margins may be visible along with color change.
Nodular melanoma accounts for 15 to 30% of melanomas. Nodular melanoma may occur anywhere on the body as a dark, bulging papule that varies from pearl to gray or black. Some lesions contain little if any pigment or may look like a vascular tumor. They are typically firm and may grow rapidly. Unless it ulcerates, nodular melanoma is often asymptomatic.
Lentigo maligna melanoma accounts for 5% of melanomas. It usually occurs on the face or other areas of chronic sun exposure. Typically, Lentigo Melanoma is a flat, tan or brown, irregularly shaped patch. It may have darker brown or black spots scattered irregularly on its surface.
Acral-lentiginous melanoma accounts for only 2 to 10% of melanomas. Although Acral-lentiginous melanoma is rare in people with lighter skin types, it is the most common type of melanoma in people with darker skin. Acral-lentiginous melanoma is observed on the palms of the hands, soles of the feet, under the nails and in the oral mucosa. It occurs on non hair-bearing surfaces of the body which may or may not be exposed to sunlight. It is also found on mucous membranes. It may appear as a longitudinal tan, black, or brown streak on the nail of a finger or toe.
Melanoma Statistics in the United States
- It is estimated that more than 137,000 cases of melanoma will be diagnosed this year.
- Melanoma is on the rise more than any other cancer.
- One person dies nearly every hour from melanoma.
- Melanoma affects people of every age and every race.
- Melanoma is the most common cancer in young adults ages 25-29 and the second most common cancer in people ages 15-29.
- The incidence rate for children 18 and under increased 84 percent from 1975 to 2005.
- Government funding for medical research, including melanoma research, has been reduced, making the work of nonprofit organizations like Outrun the Sun, Inc. essential.
For more information about clinical trials for melanoma please visit the National Cancer Institute.
For information about a clinical trial through Harvard University click here.
Other Skin Cancers
Skin cancers that are not melanomas are sometimes grouped as non-melanoma skin cancers because they develop from skin cells other than melanocytes. They tend to behave very differently from melanomas and are often treated in different ways.
Most non-melanoma skin cancers are basal cell or squamous cell cancers. They are by far the most common skin cancers, and actually are more common than any other form of cancer. Because they rarely spread (metastasize) to other parts of the body, basal cell and squamous cell skin cancers are usually less concerning and are treated differently than melanoma.
Skin Cancer Statistics in the United States
- More than 3.5 million cases of non-melanoma are diagnosed in the United States each year.
- It is estimated that one in five Americans will develop skin cancer in their life time.
- The annual cost of treating skin cancers in the U.S. is estimated at $8.1 billion. This includes $4.8 for non-melanoma skin cancers and $3.3 billion for melanoma.
American Cancer Society
World Health Organization