Letters Section Editor: Robert M. Golub, MD, Senior Editor.
To the Editor: In their study on the rising incidence of basal cell and squamous cell carcinomas in people younger than 40 years, Dr Christenson and colleagues1 cite increased exposure to UV light as a possible cause. Sunscreen itself may play a causal role in the increased exposure to UV light. Whether sunscreen is protective against melanoma has been questioned.2,3 It is difficult to study the relationship between sun exposure as a child and skin cancer 20 to 40 years later. Although it seems that the skin cancer risk resulting from 1 hour in the sun with sunscreen is lower than that from 1 hour in the sun without sunscreen, the use of sunscreen appears to have been increasing in the past 10 to 20 years, and nonmelanoma and melanoma skin cancer rates are also increasing.1,4 It is possible that because of sunscreen use, the aggregate sun exposure time per person has also increased over this time.
Neely D. Basal Cell and Squamous Cell Carcinoma in Persons Younger Than 40 Years. JAMA. 2006;295(3):278-281. doi:10.1001/jama.295.3.278-a