Sex differences in melanoma survival-a GEM study.

Area of Science:

• Oncology
• Dermatology
• Epidemiology

Background:

• Sex differences in melanoma incidence and outcomes are well-documented.
• Females exhibit a significant survival advantage in melanoma compared to males.
• The underlying reasons for this female survival advantage remain largely unexplained.

Purpose of the Study:

• To investigate the relationship between sex, clinicopathologic variables, and melanoma-specific survival.
• To determine the extent to which clinicopathologic features mediate the observed sex differences in survival.

Main Methods:

• Analysis of 1753 single primary melanomas from the Genes, Environment, and Melanoma (GEM) study.
• Utilized Cox proportional hazard models and formal mediation analysis.
• Examined the influence of age at diagnosis, Breslow thickness, ulceration, mitoses, and tumor site.

Main Results:

• Clinicopathologic features at diagnosis largely explain the effect of sex on melanoma survival.
• 86.5% of the sex effect on survival is mediated by differences in age, thickness, ulceration, mitoses, and site (HR = 1.85, P < .001).
• The direct effect of sex on survival was not significant (HR = 1.19, P = .42).

Conclusions:

• The female survival advantage in melanoma is predominantly an indirect effect.
• This advantage is mediated by favorable differences in tumor characteristics observed at diagnosis in females.
• Clinical management and research should consider these sex-mediated differences in tumor biology and presentation.