History of nonmelanoma skin cancer is associated with increased risk for subsequent malignancies

Individuals with a history of nonmelanoma skin cancer (NMSC) are at increased risk for other cancers, according to a study published in the August 26 online issue of the Journal of the National Cancer Institute. Previous studies have documented that people who have had nonmelanoma skin cancer were at increased risk for developing melanoma, but it is less well-established whether they were also at risk for cancers that do not involve the skin.

In the current study, Anthony Alberg, Ph.D., of the Medical University of South Carolina and colleagues analyzed data from a prospective cohort study called CLUE II, which was established in Washington County, Md., in 1989. Alberg's team compared the risk of malignancies in 769 individuals who had been diagnosed with nonmelanoma skin cancer and 18,405 individuals with no history of the disease during a 16-year follow-up period.

The overall incidence of cancers was 293.5 cases per 10,000 person-years in the participants with a history of nonmelanoma skin cancer and 77.8 per 10,000 in those individuals without a history of skin cancer. After adjusting for other known variables associated with cancer risk, including age, sex, body mass index, smoking status, and education level, the researchers found that individuals with a history of nonmelanoma skin cancer had a two-fold increase in the risk of subsequent cancers compared with individuals with no skin cancer history.

The increased risk remained statistically significant when the researchers removed melanoma from the list of subsequent cancers, indicating that the elevated risk was not restricted to melanoma. The association was observed for both types of nonmelanoma skin cancer, basal cell and squamous cell carcinoma.

The strongest association between a history of skin cancer and subsequent malignancies was seen in the youngest study participants, aged 25 to 44 years. "This pattern of associations, with earlier age of [nonmelanoma skin cancer] diagnosis being linked more strongly to the risk of developing subsequent malignancies, is consistent with the pattern that one would expect for a marker of inherited predisposition to cancer," the authors write.

Source: Journal of the National Cancer Institute