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

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.

A multicenter, retrospective cohort study conducted between 01/01/2000 and 01/06/2019.

Of the 33 patients included 25 (75.8 %) had vulvar (VuM) and eight (24.2 %) vaginal melanomas (VaM). VaMs were deeper: median Breslow index: 17.5mm [3.5-22] versus 4.3mm [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 1year (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 1year (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 ≥3cm 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).

A vaginal location of MM is associated with a poorer prognosis than a vulvar location.