Gynecologic tract melanoma in the contemporary therapeutic era: High rates of local and distant disease progression

Background: Gynecologic tract melanoma (GTM) is a rare malignancy with historically poor outcomes. The current study examines patterns of care and oncologic outcomes in a large single-institution cohort from the contemporary therapeutic era. Methods: Patterns of care and predictors of outcomes were evaluated for all GTM patients without metastatic disease at diagnosis who were treated at our institution between 2009 and 2020 with >6 months of follow-up. Results: Of the 124 patients included, anatomic subsites were vulvar (n = 82, 66%), vaginal (n = 34, 27%), or cervical (n = 8, 6%). Primary tumor was resected for 85% (n = 106) with surgical nodal evaluation for 60% (n = 75). Systemic therapy, most commonly immune checkpoint inhibitors (ICI, 58% systemic therapy), was used to treat all except one unresectable patient (17/18) and 33% (35/106) of resectable patients. Seven patients received neoadjuvant ICI. Fourteen patients received adjuvant radiation therapy to the pelvis (RT, 13% of those undergoing resection). With a median follow-up of 45 months, 100 patients (81%) recurred. Four-year actuarial outcomes were: 46% local control, 53% nodal control, 36% distant metastasis-free survival, 17% disease-free survival, 49% melanoma-specific survival and 48% overall survival. Mitotic rate > 10/mm², nodal involvement and non-vulvar anatomic subsite were associated with poor outcomes. Patients treated after 2016 did not have significantly better outcomes than those treated earlier. Conclusions: Patients with GTM continue to have poor outcomes in the contemporary therapeutic era with particularly notable poor local disease control relative to other mucosal melanoma subtypes. More effective oncologic therapy is needed.