Different clinico-pathological and prognostic features of vulvar, vaginal, and cervical melanomas

Female genital tract melanoma (FGTM) is a rare and aggressive melanocytic malignancy, and its clinico-pathological and prognostic features at different anatomic sites have not yet been fully described. We retrospectively analyzed and compared the clinico-pathological data and survival outcomes of patients with primary lower genital tract melanoma enrolled between January 2005 and December 2020. We identified 95 patients with FGTM, of whom 46 had vulvar melanomas (VuM), 43 had vaginal melanomas (VaM), and six had cervical melanomas (CM). The clinical characteristics of all 95 cases, including symptoms, single or multiple primary lesions, clinical stage, surgery, and histopathological characteristics of 62 primary untreated cases, including pigmentation, predominant cytology, histological pattern, mitotic figures, and tumor-infiltrating lymphocytes of VuM, VaM, and CM, differed significantly. In comparison, only trend differences in molecular alternations were evident (p = 0.077). Disease-specific survival (DSS) was 30.7% at 5 years (46.5%, 25.6%, and 44.4% for VuM, VaM and CM, respectively). Seventy-one (85.5%) patients experienced FGTM recurrence. The median time to the first recurrence was 11 months, and VaM recurred earlier than VM and CM (16, 6, and 10 months for VuM, VaM, and CM, respectively, p = 0.038). A univariate analysis of 50 cases revealed the negative factors of disease-specific survival (DSS), including the location of the vagina and the presence of ulceration, and the negative factors of recurrence-free survival (RFS), including multiple lesions, the presence of ulceration, and the presence of lymphovascular invasion. Multiple lesions showed a borderline correlation with DSS. A multivariate Cox regression analyses of 50 cases revealed that the presence of ulceration was associated with shorter DSS and RFS (yes vs. no, Hazard Ratio = 2.400 and 2.716, respectively). Vaginal location showed a significant correlation with DSS (Hazard Ratio = 2.750, p = 0.024). In conclusion, vulval, vaginal, and cervical melanomas may differ in terms of their clinico-pathological features and associations with DSS and RFS. Ulceration and vaginal location were significantly associated with shorter DSS, and ulceration was associated with an increased risk of FGTM recurrence.