Melanoma risk in relation to use of sunscreen or other sun protection methods

Abstract

Background: Epidemiologic evidence supporting sunscreen for melanoma prevention is limited to one small trial; case-control studies report conflicting results. Sunscreen usage patterns or alternative sun protection methods have rarely been studied in relation to melanoma.

Methods: In a population-based case-control study, participants (1,167 cases; 1,101 controls) reported for each decade year of age outdoor activity-related sunscreen use, sunscreen patterns (SPF15+, amount, skin coverage, reapplication, routine use), and use of other sun protection methods (like hats, long-sleeved shirts, staying in the shade). Scores were averaged across activities and/or decades; scores in the most recent two decades were used to classify individuals as non-, inconsistent- or optimal users. Adjusted mean score differences between cases and controls, and ORs and 95% CIs for melanoma among optimal-, inconsistent- versus nonusers were calculated.

Results: Mean scores for sunscreen, sunscreen patterns or other sun protection methods were low, but higher among controls than cases for SPF15+ sunscreen (P = 0.03) and other sun protection methods (P = 0.006). Adjusted ORs for optimal use of sunscreen and most sunscreen patterns were null or relatively weak, except for routine sunscreen (adjusted OR = 0.44, 95% CI: 0.23-0.86). Optimal use of other sun protection methods was inversely associated with melanoma (adjusted OR = 0.59, 95% CI: 0.44-0.78).

Conclusions: Optimal use of routine sunscreen or other sun protection methods were most strongly associated with decreased melanoma risk; results are limited by the small number of subjects who used sunscreen routinely and lack of specificity regarding other sun protection methods.

Impact: Both improving sunscreen practices and encouraging sun avoidance strategies may be important for melanoma prevention.

Figure 1

Mean sunscreen use (0 = never to 5 = almost always) among controls by decade age and reference age at time of interview.