Researchers observe an increased risk of cancer in people with history of non-melanoma skin cancer

The researchers found that people with a history of non-melanoma skin cancer had a modestly increased risk of getting cancer in the future, specifically breast and lung cancer in women and melanoma in both men and women. Non-melanoma skin cancer, which includes basal cell and squamous cell carcinoma, is the most common form of cancer in the United States.

The study will be published on April 23, 2013 in PLOS Medicine.

The researchers analyzed data from two large United States cohort studies -- the Health Professionals Follow-up Study and the Nurses' Health Study. The researchers followed 46,237 men from June 1986 to June 2008 in the Health Professionals Follow-up Study, and 107,339 women from June 1984 to June 2008 in the Nurses' Health Study. The researchers identified 36,102 new cases of non-melanoma skin cancer and 29,447 new cases of other primary cancers.

A history of non-melanoma skin cancer was significantly associated with a 15 percent higher risk of other primary cancers in men, and a 26 percent higher risk of other primary cancers in women. When melanoma was excluded from this analysis, the rates changed slightly, with a history of non-melanoma skin cancer associated with an 11 percent higher risk of other primary cancers in men, and a 20 percent higher risk of other primary cancers in women.

After using statistical models to correct for multiple comparisons, looking at individual cancer sites, the researchers found that a history of non-melanoma skin cancer was significantly linked to an increased risk of breast and lung cancer in women, and an increased risk of melanoma in both men and women.

According to the researchers, these findings should be interpreted cautiously.

"Because our study was observational, these results should be interpreted cautiously and are insufficient evidence to alter current clinical recommendations," said Jiali Han, PhD, Channing Division of Network Medicine, BWH Department of Medicine and BWH Department of Dermatology. "Nevertheless, these data support a need for continued investigation of the potential mechanisms underlying this relationship."