Sex differences in survival of cutaneous melanoma are age dependent

Abstract

This study identified sex differences in clinical presentation and survival for primary cutaneous melanoma without clinical evidence of metastasis at diagnosis from 1976 to 2008 in southern Germany. Melanoma-specific survival curves and estimated survival probabilities were generated using the Kaplan-Meier method. Multivariate survival analyses were carried out using the Cox modeling. Male patients had significantly thicker and more frequently ulcerated tumors and a lower 10-year disease-specific survival (DSS) and recurrence-free survival probability compared with females among patients of 43 years old or younger (DSS: 86.1 vs. 93.2%, P<0.001) and 44-60 years old (DSS: 83.5 vs. 90.1%, P<0.001). The survival advantage of female patients in terms of 10-year DSS and 10-year recurrence-free survival was not observed after an age of 60 years (P=0.21 and 0.51, respectively). Sex was of prognostic importance for DSS and survival after recurrence [hazards ratio (HR): 1.3; 95% confidence interval (CI): 1.1-1.6; P=0.002 and HR: 1.2; 95% CI: 1.0-1.5; P=0.018, respectively]. Stratified by age groups, sex remained of prognostic importance for DSS only in patients of 43 years or younger, and 44-60 years old (HR: 1.5; 95% CI: 1.0-2.1; P=0.03 and HR: 1.4; 95% CI: 1.1-2.0; P=0.02, respectively). Sex is an independent prognostic factor in surviving melanoma. The sex difference in survival with a better outcome for women is confined to melanoma patients of 60 years and younger. In addition, in younger age groups, male patients present with prognostically unfavorable features of primary melanoma. A female survival advantage is also known for other solid tumors such as colon and lung cancer; however, age dependency has not been studied.