The study aimed to provide a synopsis of recent research advances in the epidemiology of keratinocyte carcinoma (KC), with a focus on indoor tanning and known risk factors for other forms of cancer such as cigarette smoking and alcohol drinking.

The evidence is strong enough to infer that use of ultraviolet radiation (UVR)-emitting indoor tanning devices causes KC. Epidemiologic studies of cigarette smoking, alcohol drinking, and menopausal hormone therapy tend to show some suggestion for increased risk of KC but the evidence is not yet strong enough to determine if there is a true etiologic role. Body mass index is clearly inversely associated with KC risk, but this is more likely to be due to lower UVR exposure in overweight and obese individuals than it is due to a true etiologic role.

The epidemic of KC continues unabated, and the causal role of indoor tanning is contributing to this unfavorable trend in KC incidence rates. Advances in understanding the etiology of KC should not divert attention away from the fact that the primary public health strategy to prevent KC is known: minimize population exposure to UVR from the sun and from UVR-emitting indoor tanning devices, particularly among those with sun-sensitive phenotypes.