The analysis, led by Dr. Jiali Han, an Associate Professor from Brigham and Women's Hospital, Harvard Medical School in the US, found that men and women with a history of non-melanoma skin cancers—the most common form of cancer in the United States and includes basal cell and squamous cell carcinoma—had a 15% and 26% increased risk, respectively, of developing another form of cancer compared with those who had no such history.
The researchers (also the authors of the published paper), reached these conclusions by analysing information from two large US cohorts (group) studies followed till 2008—the Health Professionals Follow-up Study (which enrolled 51,529 male health professionals in 1986) and the Nurses' Health Study (which enrolled 121,700 female nurses in 1976).
The authors identified 36,102 new cases of non-melanoma skin cancer and 29,447 new cases of other cancers in white participants. When excluding melanoma, the authors found that a history of non-melanoma skin cancer was linked to an 11% higher risk of other cancers in men and a 20% higher risk of other cancers in women. After correction for multiple comparisons, the authors found that a history of non-melanoma skin cancer was significantly linked to an increased risk of breast and lung cancer in women and of melanoma in both men and women.
The authors say: "This prospective study found a modestly increased risk of subsequent malignancies among individuals with a history of non-melanoma skin cancer, specifically breast and lung cancer in women and melanoma in both men and women."
They continue: "Because our study was observational, these results should be interpreted cautiously and are insufficient evidence to alter current clinical recommendations."
The authors add: "Nevertheless, these data support a need for continued investigation of the potential mechanisms underlying this relationship."