Skin microtopography as a measure of photoaging and risk of squamous cell carcinoma of the skin in a US population

BackgroundSkin microtopography as a measure of photoaging is a noninvasive approach to measuring chronic ultraviolet radiation exposure and reflects the degree of dermal elastosis in populations of European descent in the subtropics. Less is known about the utility of this approach in populations at different latitudes, and whether it relates to skin cancer risk. MethodsA population-based case-control study of 342 squamous cell carcinoma (SCC) cases and 331 age- and gender-matched controls were evaluated for histologic evidence of solar damage and severity of photoaging based on microtopography on a six-grade scale. Odds ratios (OR) for SCC associated with degree of photoaging were estimated using logistic regression analysis adjusted for potentially confounding factors. ResultsAfter adjustment for known risk factors, SCC was associated with increasing photoaging grade (OR=1.7, 95% CI=0.9-3.0 for severe photoaging; OR=2.8, 95% CI=1.6-5.0 for very severe photoaging). Associations remained among those with actinic keratosis (OR=3.4, 95% CI=0.9-12.4 for severe photoaging, OR=5.7, 95% CI=1.7-19.6 for very severe photoaging). LimitationsThere was limited statistical power, particularly for subgroup analyses. ConclusionOur findings provide further evidence of microtopography as an independent, objective indicator of risk of SCC.