Gender differences in melanoma prognostic factors

Background: Although previous studies identify gender differences in melanoma, limited research on the phenomenon exists. Methods: In this retrospective chart review, 1,156 adults diagnosed with melanoma, between 2006-2016, at the University of Colorado were included. Breslow depth, mitotic rate, ulceration status, and location were extracted from charts between March and August 2016. Cochran-Armitage trend tests and cumulative logistic regression were used to examine the association between gender and Breslow depth, univariately and after adjusting for potential confounders. Results: In univariate analysis, males were significantly more likely to present with lesions with higher Breslow depths (p for trend=0.005). In models adjusted for age, melanoma subtype, and location, males were marginally more likely to present with lesions with higher Breslow depths (cumulative OR: 1.261, 95% CI: 0.988-1.611, p=0.060). Males were also marginally more likely to present with lesions with higher mitotic rates, after further adjustments for all other prognostic factors (cumulative OR: 1.244, 95% CI: 0.979-1.580, p=0.074). Limitations: This was a retrospective single-institution study. Conclusion: Differences in mitotic rates among melanomas in males versus females, even after adjustments for all other prognostic factors, suggests that biological differences may contribute to the female prognosis advantage.