Prolonged Prevention of Squamous Cell Carcinoma of the Skin by Regular Sunscreen Use

TLDR

Half of all cancers in the United States are skin cancers. The study followed participants for an additional 8 years after the trial to assess long‑term prevention of basal and squamous cell carcinomas. Extended follow‑up showed sunscreen use reduced squamous cell carcinoma incidence by about 40 % but did not significantly lower basal cell carcinoma rates. Published in Cancer Epidemiology, Biomarkers & Prevention 2006;15(12):2546–8.

Abstract

Abstract Half of all cancers in the United States are skin cancers. We have previously shown in a 4.5-year randomized controlled trial in an Australian community that squamous cell carcinomas (SCC) but not basal cell carcinomas (BCC) can be prevented by regular sunscreen application to the head, neck, hands, and forearms. Since cessation of the trial, we have followed participants for a further 8 years to evaluate possible latency of preventive effect on BCCs and SCCs. After prolonged follow-up, BCC tumor rates tended to decrease but not significantly in people formerly randomized to daily sunscreen use compared with those not applying sunscreen daily. By contrast, corresponding SCC tumor rates were significantly decreased by almost 40% during the entire follow-up period (rate ratio, 0.62; 95% confidence interval, 0.38-0.99). Regular application of sunscreen has prolonged preventive effects on SCC but with no clear benefit in reducing BCC. (Cancer Epidemiol Biomarkers Prev 2006;15(12):2546–8)