Invasive cutaneous squamous cell carcinoma incidence in US health care workers.

Little data on cutaneous squamous cell carcinoma (SCC) epidemiology within the United States are currently available. Prior studies have focused on populations outside of the United States or been limited to regions within the US. In this study, prospective data were collected via biennial questionnaires from a total of 261,609 participants, which included women in the Nurses' Health Study (NHS, 1976-2008) and Nurses' Health Study II (NHS II, 1989-2009), and men in the Health Professionals Follow-Up Study (HPFS, 1986-2008). History of physician-diagnosed invasive SCC was confirmed by pathology record review. Over the entire follow-up period for each cohort, there were 1,265 invasive SCC cases per 100,000 persons in the NHS cohort, 389 cases per 100,000 persons in NHS II, and 2,154 cases per 100,000 persons in HPFS. An 18-year follow-up of participants in these cohorts revealed increasing invasive SCC incidence rates over time, with rates for men being consistently higher than those for women. In women, a larger proportion of invasive SCC lesions occurred on the lower extremities as compared to men (21 % in NHS vs. 6 % in HPFS, p < 0.0001; 14 % in NHS II vs. 6 % in HPFS, p < 0.0001), while in men, a larger proportion occurred on the head/neck (43 % in NHS vs. 60 % in HPFS, p < 0.0001; 48 % in NHS II vs. 60 % in HPFS, p < 0.0001). In summary, invasive SCC incidence rates among US men have been greater than those for women with distinct sites of common occurrence between men and women.