Incidence and Mortality

Skin cancer is the most common cancer in the United States, affecting more than 1,000,000 Americans every year. It accounts for more than 10,000 deaths annually,[1] which represents approximately 4% of all cancer deaths.[2]

Skin cancers are easily detected clinically and are often cured by excisional biopsy alone. This does not mean that they are unimportant or can be neglected without adverse consequences. When neglected, they can be disfiguring and/or cause death.

There are three major types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and cutaneous melanoma. Basal cell carcinoma has the highest incidence and melanoma has the lowest. Basal and squamous cell carcinomas have an excellent prognosis, but persons diagnosed with these nonmelanomatous skin cancers are at higher risk for developing additional skin cancers.[3] Melanoma, which is the focus of this summary, accounts for approximately three-fourths of all skin cancer deaths.

Mortality from melanoma increased after the 1970s, especially in white males.[4,5] In the 1990s, melanoma mortality rates stabilized. In 2007, it is estimated that 59,940 individuals are expected to develop melanoma, and about 8,110 are expected to die of this disease.[1] In the United States, observed incidence increased 126% between 1973 and 1995, at a rate of approximately 6% per year,[6] though incidence rates appear also to have stabilized in the 1990s.[5] A study of skin biopsy rates in relation to melanoma incidence rates obtained from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute indicated that much of the observed increase in incidence between 1986 and 2001 was confined to local disease and was most likely caused by overdiagnosis as a result of increased skin biopsy rates during this period.[7]

Risk Factors

The incidence of melanoma rises rapidly in Caucasians after age 20 years. Fair-skinned individuals exposed to the sun are at higher risk. The best defense against skin cancer is protection from the sun and ultraviolet light, though the effectiveness of sunscreens in preventing melanoma has been challenged.[8] (Refer to the PDQ summary on Prevention of Skin Cancer for more information.) Individuals with certain types of pigmented lesions (dysplastic or atypical nevi), with several large nondysplastic nevi, with many small nevi, or with moderate freckling have a twofold to threefold increased risk of developing melanoma.[9] Individuals with familial dysplastic nevus syndrome or with several dysplastic or atypical nevi are at high (>fivefold) risk of developing melanoma.[9]

References:

1. American Cancer Society.: Cancer Facts and Figures 2007. Atlanta, Ga: American Cancer Society, 2007. Also available online. Last accessed December 20, 2007.
2. American Cancer Society.: Cancer Facts and Figures 2006. Atlanta, Ga: American Cancer Society, 2006. Also available online. Last accessed January 18, 2008.
3. Karagas MR, Greenberg ER, Mott LA, et al.: Occurrence of other cancers among patients with prior basal cell and squamous cell skin cancer. Cancer Epidemiol Biomarkers Prev 7 (2): 157-61, 1998.
4. Wingo PA, Ries LA, Rosenberg HM, et al.: Cancer incidence and mortality, 1973-1995: a report card for the U.S. Cancer 82 (6): 1197-207, 1998.
5. Hall HI, Miller DR, Rogers JD, et al.: Update on the incidence and mortality from melanoma in the United States. J Am Acad Dermatol 40 (1): 35-42, 1999.
6. Ries LA, Kosary CL, Hankey BF, et al., eds.: SEER Cancer Statistics Review 1973-1995. Bethesda, Md: National Cancer Institute, 1998.
7. Welch HG, Woloshin S, Schwartz LM: Skin biopsy rates and incidence of melanoma: population based ecological study. BMJ 331 (7515): 481, 2005.
8. Dennis LK, Beane Freeman LE, VanBeek MJ: Sunscreen use and the risk for melanoma: a quantitative review. Ann Intern Med 139 (12): 966-78, 2003.
9. Gandini S, Sera F, Cattaruzza MS, et al.: Meta-analysis of risk factors for cutaneous melanoma: I. Common and atypical naevi. Eur J Cancer 41 (1): 28-44, 2005.