Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: Our study investigated trends over time in nonmelanoma skin cancer, consisting of basal cell carcinoma and squamous cell carcinoma. It showed that the incidence is rising in persons younger than 40 years in Olmsted County, Minnesota. Our study was not designed to address the etiology of these trends, but we do discuss potential causes, with increased sun exposure being an obvious concern and increased surveillance a consideration.
In response to Dr Neely, unlike melanoma, which has a multifactorial etiology, we know that the most likely cause of nonmelanoma skin cancer is UV-B exposure.1 Sunscreen is highly effective in blocking UV-B rays. Therefore, a hypothetical increased risk of nonmelanoma skin cancer associated with sunscreen may be less than that debated for melanoma.2
Christenson LJ, Borrowman TA, Vachon CM, Tollefson MM, Otley CC, Weaver AL, Roenigk RK. Basal Cell and Squamous Cell Carcinoma in Persons Younger Than 40 Years—Reply. JAMA. 2006;295(3):278-281. doi:10.1001/jama.295.3.279-b