Immunotherapy toxicities in metastatic vulvar and vaginal melanomas: a retrospective cohort study

This retrospective cohort study examined the factors for patients with metastatic vulvar and vaginal melanomas on immune checkpoint inhibitors. The study included all patients over the age of 18 who received either anti-cytotoxic T-lymphocyte-4 (anti-CTLA-4) therapy or anti-programmed cell death protein-1 (anti-PD-1) therapy at the Sunnybrook Hospital from June 2012 to December 2018. There were 11 patients with vulvar or vaginal melanoma on immune checkpoint inhibitor therapy. The main sites of metastasis included the lungs, lymph nodes, soft tissues, and liver. The majority of patients received prior radiation therapy (7/11) and prior surgical therapy (9/11). There were no differences in overall survival for vulvar or vaginal melanomas on anti-PD-1 vs. anti-CTLA-4 therapy (p > 0.05). There were no significant differences in overall survival for vulvar and vaginal vs. cutaneous melanoma (p > 0.5). There were no significant differences in overall survival in patients with vulvar and vaginal melanoma in the presence vs. absence of immune-related adverse events (p > 0.05), yet there was a significant difference in patients with cutaneous melanoma in the presence vs. absence of immune-related adverse events (p < 0.05). Knowledge of the presentation and outcome of vulvar and vaginal melanomas is important for clinical practice in gynecology.