Role of Age and Sex in the Diagnosis of Early-stage Malignant Melanoma: A Cross-sectional Study

Age and sex have been identified as predictors of outcome in malignant melanoma (MM). The aim of this multicentre, cross-sectional study was to analyse the role of age and sex as explanatory variables for the diagnosis of thin MM. A total of 2,430 patients with MM were recruited. Cases of in situ (Tis) and T1 MM were more frequent than T2-T4 MM (56.26% vs. 43.74%). Breslow thickness increased throughout decades of life (analysis of variance (ANOVA) p<0.001), with a weak correlation between Breslow thickness and patient's age (r=0.202, p<0.001). Breslow thickness was significantly less in women (1.79 vs. 2.38 mm, p=0.0001). Binary logistic regression showed a significant (p<0.001) odds ratio for age 0-29 years (1.18), and 30-59 years (1.16), and for women (1.09). Age and sex explained 3.64% of the variation observed in Tis-T1 frequency (R-2=0.0364). Age and sex appear to explain a low percentage of the variation in the early detection of MM.