Survival outcomes in gynecologic melanomas: A population based analysis.

e17656 Background: Gynecologic melanomas are rare and aggressive malignancies arising in the vulva, vagina, cervix, uterus, and ovary. Unlike cutaneous melanomas, these cancers are not strongly associated with ultraviolet (UV) radiation exposure. Their etiology remains largely unclear, with genetic and hormonal factors as suspected contributors. Gynecologic melanomas account for 1% to 3% of all melanomas in women and are associated with a markedly poor prognoses. This study describes the clinical and demographic characteristics of gynecologic melanoma patients to identify key predictors of survival. Methods: Data for gynecologic melanoma cases diagnosed between 2000 and 2021 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Survival outcomes were evaluated through Kaplan-Meier survival analysis and Cox proportional hazards models. Results: A total of 1,623 patients were diagnosed with gynecologic melanoma between 2000 and 2021. Complete records were analyzed in 1,269 cases: 1,187 vulvar, 390 vaginal, 36 cervical, 5 ovarian, and 5 uterine melanomas. Survival outcomes varied significantly by anatomical location. Vulvar, ovarian and uterine melanoma had the most favorable prognoses. Vulvar melanoma had a 5-year survival of 55.0% (95% CI: 51.9%–58.3%) and overall survival of 40% (95% CI: 35.3%–44.1%), with a median survival of 81 months. Ovarian melanoma had with a 5-year survival of 60% (95% CI: 29.3%–100.0%) and overall survival of 40% (95% CI: 13.7%–100.0%), with a median survival of 70 months. Uterine melanoma demonstrated excellent outcomes, with 100% survival at 5 years among five cases. Although there were a low number of cases, cervical and vaginal melanomas showed the poorest outcomes, with cervical melanoma having a 5-year survival of 17% (95% CI: 6.5%–42.1%), overall survival of 8% (95% CI: 1.6%–43.9%), and a median survival of 16 months. Vaginal melanoma had a 5-year survival of 20% (95% CI: 16.0%–25.5%) and an overall survival of 15% (95% CI: 11.2%–21.0%), with a median survival of 18.0 months. Survival analysis revealed that age, stage at diagnosis, and surgical treatment significantly influenced outcomes for vulvar and vaginal melanoma. For vulvar melanoma, race, radiation therapy, and chemotherapy also impacted survival. Vulvar melanoma patients diagnosed in nonmetropolitan counties were more likely to die compared to patients in metropolitan counties with over 1 million population (HR=1.49, 95% CI: 1.02–2.20, p=0.04). Likely due to low numbers, no significant prognostic factors were identified for cervical, ovarian or uterine melanoma. Conclusions: Survival outcomes for gynecologic melanomas were significantly influenced by age, stage at diagnosis, surgical treatment, radiation therapy, and chemotherapy. Further research is necessary to refine diagnostic and therapeutic strategies for this rare form of gynecologic melanoma.