A randomized trial showed no significant difference in the rate of invasive melanoma between patients taking daily aspirin and those taking a placebo. There were slightly fewer melanoma events in the aspirin group than in the placebo group — 177 and 189, respectively — but the difference between the groups was not statistically significant (hazard ratio [HR], 0.94; 95% CI, 0.77-1.16; P =.58). Similarly, there were slightly fewer invasive melanoma events in the aspirin group than in the placebo group — 76 and 94, respectively — but the between-group difference was not significant (HR, 0.81; 95% CI, 0.60-1.10; P =.18).