Sunbed Use Increases Cutaneous Squamous Cell Carcinoma Risk in Women: A Large-scale, Prospective Study in Sweden.

The incidence of cutaneous squamous cell carcinoma has increased rapidly in Sweden in the past decades. Here, we present a prospective study of the Melanoma in Southern Sweden (MISS)-cohort, with 29,460 participating women in southern Sweden that investigates the risk factors for cutaneous squamous cell carcinoma. Data on the host and skin cancer risk factors were collected through questionnaires and then matched with the National Cancer Registry. Statistical analyses were based on uni- and multivariable Cox proportional hazards models, using age as the time-scale. We found that sunbed use (hazard ratio (HR) 1.2, 95% CI: 1.1-1.4), red and light blond hair (HR 1.6, 95% CI: 1.1-2.3), freckles (HR 1.4, 95% CI: 1.1-1.8) and immunosuppressive medications (HR 2.1, 95% CI: 1.3-4.5) were independent risk factors. Furthermore, we observed a dose-dependent relationship between sunbed use and the development of cutaneous squamous cell carcinoma. Our findings support the idea of integrating dermatological follow-up examinations for immunosuppressed patients and banning the use of sunbeds in order to prevent cutaneous squamous cell carcinoma.