Vulvar and vaginal melanomas: A retrospective study spanning 19 years from a tertiary center

Introduction Mucosal melanomas (MM) of the female genital tract are rare a. We aimed to study the prognostic factors of vulvar and vaginal locations of MM. Material and method A multicenter, retrospective cohort study conducted between 01/01/2000 and 01/06/2019. Result Of the 33 patients included 25 (75.8 %) had vulvar (VuM) and eight (24.2 %) vaginal melanomas (VaM). VaMs were deeper: median Breslow index: 17.5 mm [3.5−22] versus 4.3 mm [0.35−18] (p = 0.013). Average follow-up was 24.0 ± 59.8 months. Twenty-six patients (78.8 %) experienced recurrence. Disease-free survival was 52.9 % at 1 year (64.7 % for VuM and 14.3 % for VaM) and 8.4 % at 3 years (11 % for VuM and 0% for VaM) (p = 0.002). Median time to the first recurrence was 9.01 months [CI95 %: 2.07–56.71]. VaM recurred earlier than VuM (3.12 months [CI95 %: 2.07–12.49] versus 17.72 [CI95 %: 3.58–56.71], p = 0.011). VaM had a higher risk of recurrence (HR = 5.64 [CI95 %: 2.01–15.82], p = 0.001) in multivariate analysis. Overall survival was 88.5 % at 1 year (100 % for VuM and 50 % for VaM), and 59.4 % at 3 years (69.3 % for VuM and 25 % for VaM). Women with VaM died earlier: median specific death occurrence of 8.76 months [CI95 %: 6.54–24.72] versus 39.61 [CI95 %: 21.89–209.21], p = 0.013 (HR = 5.08 [CI95 %: 1.39–18.60], p = 0.014). A lesion size ≥3 cm was associated with an increased risk of mortality (HR = 8.45 [CI95 %: 1.60–44.52], p = 0.012). In multivariate analysis, vaginal location remained an independent and predictive variable of a higher risk of specific death (HR = 8.56 [CI95 %: 1.95–37.64], p = 0.005). Conclusion A vaginal location of MM is associated with a poorer prognosis than a vulvar location.