Rates of both basal cell carcinoma and squamous cell carcinoma have increased over time among people under the age of 40, according to a study published in the Journal of the American Medical Association (JAMA).
Skin cancer is the most common type of cancer. It is generally divided into two categories: melanoma and non-melanoma. Non-melanoma skin cancer is much more common than melanoma, but also more curable. The most common types of non-melanoma skin cancer are basal cell carcinoma and squamous cell carcinoma. Basal cell carcinomas account for a majority of skin cancers in both men and women. Basal cell carcinomas are slow growing and most commonly appear on sun-exposed areas of the skin. Squamous cell carcinomas are less common than basal cell carcinomas, and tend to be more aggressive. Like basal cell carcinomas, squamous cell carcinomas tend to appear on sun-exposed skin.
The frequency of non-melanoma skin cancer is known to be increasing in older adults, but there is less information available about skin cancer trends in younger adults. To assess trends in the frequency of non-melanoma skin cancer in younger adults, researchers conducted a study among residents under the age of 40 in Olmsted County, Minnesota. Information was collected about non-melanoma skin cancers diagnosed between 1976 and 2003. They identified a total of 451 basal cell carcinomas and 70 squamous cell carcinomas.
Between 1976 and 2003, rates of basal cell carcinoma increased significantly among women but not among men. Among women, the rate of basal cell carcinoma increased from 13 cases per 100,000 members of the population during the years 1976-1979 to 32 cases per 100,000 during 2000-2003. By comparison, the rates of basal cell carcinoma in men were 23 cases per 100,000 during 1976-1979 and 27 cases per 100,000 during 2000-2003.
Rates of squamous cell carcinoma also increased between 1976 and 2003, and the increase affected both men and women. Among men and women combined, the rate of squamous cell carcinoma increased from roughly one case per 100,000 members of the population in 1976-1979 to roughly four cases per 100,000 in 2000-2003.
In light of the increasing frequency of non-melanoma skin cancer in younger adults, the researchers emphasize the importance of skin-cancer prevention messages. Risk of non-melanoma skin cancer can be decreased by avoiding sun exposure, wearing sun-protective clothing and hats, and using sunscreen.
Reference: Christenson LJ, Borrowman TA, Vachon CM. Incidence of basal cell and squamous cell carcinomas in a population younger than 40 years. JAMA. 2005;294:681-690.