Canadian Study of Non-Melanoma Skin Cancer and Ultraviolet Radiation
Posted: Friday, March 19, 2021
For White people in Canada in 2015, an estimated 46% of basal cell carcinomas and 17% of squamous cell carcinomas were associated with sunburn, sunbathing, and indoor tanning behaviors, according to a recent study. Will D. King, PhD, of Queen’s University in Kingston, Ontario, Canada, and colleagues published their results in Cancer Causes & Control.
“Basal cell carcinoma [was] strongly associated with sunburn and sunbathing,” the authors wrote, “while evidence suggests that squamous cell carcinoma is only moderately associated with sunburn and is not related to sunbathing at all.”
The authors estimated the burden of basal cell carcinoma and squamous cell carcinoma associated with ultraviolet radiation by comparing 2015 overall incidence rates with rates on the trunk and lower limbs, which are less exposed to ultraviolet radiation. The comparison was adjusted for estimated surface areas. The researchers assessed the burden of carcinomas associated with ultraviolet radiation–related behaviors (sunburn, sunbathing, and indoor tanning) using estimates for Caucasians from the Second National Sun Survey and meta-analyses of other studies to generate relative-risk data.
The researchers estimated that 46% of basal cell carcinomas and 17% of squamous cell carcinomas in Canada in 2015 were associated with adult sunburn, sunbathing, and indoor tanning combined. The authors estimated that 19% of basal cell carcinomas were associated with adult sunburn, compared with only 10% of squamous cell carcinomas. “Cutaneous squamous cell carcinomas are primarily a product of general exposure to the sun,” the authors wrote.
Its reliance on self-reported exposure limits the study. The authors noted that they likely underestimated the percentage of non-melanoma skin cancers associated with ultraviolet radiation because the “less-exposed” areas in the analysis, the trunk and lower limbs, are still exposed to some ultraviolet radiation.
Disclosure: The study authors reported no conflicts of interest.