Effect of biology on the outcome of female melanoma patients.

The aim of the present study was to investigate plausible explanations for the favorable outcome of female melanoma patients and determine the effect of biology on this outcome. Data from 1,169 cutaneous melanoma patients were retrospectively analyzed. Cox proportional hazards models were used and the confounding factors on the survival difference were analyzed by a forward step multivariate modification method. The majority of the factors contributing to poor prognosis were significantly more pronounced in male melanoma patients. After the survival advantage of female patients (P=0.0001 on univariate analysis) was confounded (P=0.708 on multivariate analysis) following adjustment for the prognostic factors, two factors (neurotropism and vertical growth phase) were identified as the confounders, and this effect was attributed to the small number of patients in the groups of these two variables. The already known female advantage in melanoma survival was not affected by other prognostic factors, and female sex remained an independent predictor of good survival in melanoma. This sex-related independent survival advantage was attributed to a biological characteristic that has not yet been fully elucidated, but may be more closely associated with host-related rather than melanoma-related factors.