Improved survival in women versus men with merkel cell carcinoma

Studies have observed that women have better outcomes than men in melanoma, but less is known about the influence of sex differences on outcomes for other aggressive cutaneous malignancies.

To investigate whether women and men have disparate outcomes in Merkel cell carcinoma (MCC).

Patients with nonmetastatic MCC undergoing surgery and lymph node evaluation were identified from the National Cancer Database (NCDB) and the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier analysis and Cox proportional hazards regression models were used for overall survival, and competing-risks analysis and Fine-Gray models were used for cause-specific and other-cause mortality.

The NCDB cohort (n = 4178) included 1516 (36%) women. Women had a consistent survival advantage compared with men in propensity score-matched analysis (66.0% vs 56.8% at 5 years, P < .001) and multivariable Cox regression (hazard ratio, 0.68; 95% confidence interval, 0.61-0.75; P < .001). Similarly, women had a survival advantage in the SEER validation cohort (n = 1202) with 457 (38.0%) women, which was entirely due to differences in MCC-specific mortality (5-year cumulative incidence: 16.4% vs 26.7%, P = .002), with no difference in other-cause mortality (16.8% vs 17.8%, P = .43) observed in propensity score-matched patients.

Potential selection bias from a retrospective data set.

In MCC, women have improved survival compared with men, driven by MCC-related mortality.