Melanoma survival is superior in females across all tumour stages but is influenced by age

Kiarash Khosrotehrani, Paramita Dasgupta, Lisa Byrom, Danny R. Youlden, Peter D. Baade, Adele C. Green

Among patients with invasive melanoma, females are known to have higher survival than males globally. However, this survival advantage has not been explored in thin melanomas, the most common form of the disease. In addition, it is unclear if this advantage is true across all age groups. We aimed to compare melanoma survival between males and females by clinical stage and within age groups. Melanomas from 1995 to 2008 were extracted from the Queensland Cancer Registry and the Surveillance, Epidemiology, and End Results (SEER) Program, and melanoma-specific deaths were ascertained up to 2011. Flexible parametric survival models compared survival between groups. The Queensland cohort of 28,979 patients experienced 1712 melanoma deaths and the SEER cohort of 57,402 patients included 6929 melanoma deaths. Survival rates were in favour of females across nearly all tumour stages, including thin invasive tumours in both cohorts after adjusting for demographic and clinical factors [odds ratio (OR) death female:male for stage I melanoma = 0.64 in Queensland; and OR = 0.79 in the US, both P < 0.001]. The sex influence on survival interacted with age categories. In particular, the survival advantage was inconsistent in females with stage I melanoma aged under 60. Females with melanoma have a survival advantage over males including in stage I melanomas. However, this advantage is dependent on age at diagnosis, suggesting an underlying biological mechanism influenced by age that exists from the very early stages of the disease.