Investigating the role of immunotherapy in advanced/recurrent female genital tract melanoma: a preliminary experience.

Objective: immunotherapy with immune checkpoint inhibitors has become one of the standard therapeutic modalities for patients with advanced melanoma. Melanoma of the female lower genital tract is a rare and aggressive disease, with poor long-term clinical outcomes. To date, no study evaluated the role of immunotherapy in metastatic melanoma of the lower genital tract.

Methods: Data of women with metastatic melanoma of the lower genital tract were prospectively collected. Survival outcomes over time was assessed using Kaplan-Meier model.

Results: Seven cases of metastatic melanoma of the lower genital tract (vulva [n=2], vagina [n=4], and uterine cervix [n=1]) treated with immune checkpoint inhibitors are reviewed. Two patients had metastatic disease at diagnosis, while 5 patients developed metastatic disease at a mean (standard deviation) time of 9.9 (±3.0) months from primary diagnosis. Four patients received an anti-cytotoxic T lymphocyte-associated antigen 4 (CTLA4) (ipilimumab) and 3 received an anti-programmed cell death 1 (PD-1) (pembrolizumab [n=2], nivolumab [n=1]) therapy. The response rate to immunotherapy was 28.5%. Patients receiving an anti-PD-1 experienced a better progression-free survival than patients treated with anti-CTLA4 (p=0.01, log-rank test). Although not reaching statistical significance, overall survival was better in patients having an anti-PD-1 therapy in comparison to anti-CTLA4 (p=0.15, log-rank test).

Conclusion: Results from our series confirm the poor prognosis of women with metastatic melanoma of the lower genital tract, thus supporting the need of exploring new treatment modalities. Further studies are warranted to improve knowledge on the role of immunotherapy in metastatic melanoma of the lower genital tract.