Role of immunotherapy in the management of primary melanoma of the vagina: A national analysis of a rare aggressive malignancy

Background and objectives

Primary melanoma of the vagina (PMV) is a rare, aggressive gynecological malignancy that presents significant challenges to women’s health. Despite advancements in immunotherapy (IO), the impact of IO on PMV remains unknown. This study aims to investigate prognostic factors associated with long-term survival in patients with PMV.

Methods

The National Cancer Database was queried from 2004 to 2019 to identify patients with PMV. Demographics, tumor characteristics, and treatment type were evaluated. The Kaplan Meier method was used to estimate overall survival (OS). Multivariate Cox regression analysis was performed to determine predictors of survival.

Results

Our cohort included 884 women with PMV; 16.0 % were treated with IO. There were no differences in 5-year overall survival based on pathological characteristics or receipt of IO. Surgical resection was associated with improved 5-year OS (24.4 % vs. 8.6 %, p < 0.001). Five-year OS was higher in patients who underwent lymphadenectomy (31.0 % vs. 19.4 %, p = 0.003) and who had negative surgical margins (28.0 % vs. 21.0 %, p = 0.04). Among patients who did not undergo surgery, those who received IO had nearly 2-fold higher 5-year OS, but this did not reach significance (13.7 % vs. 7.7 %, p = 0.066). On multivariable analysis, older age, nodal metastasis, and higher comorbidity were independent predictors of poor OS, while receipt of IO was not. Surgical resection was the strongest independent predictor of improved OS.

Conclusions

Surgical intervention with lymphadenectomy and negative margins was associated with prolonged survival in patients with PMV, while IO was not. Further investigation is needed to identify optimal treatment strategies for PMV.

Synopsis

In this retrospective study of patients diagnosed with primary melanoma of the vagina, immunotherapy offered limited survival benefit, regardless of curative-intent surgery. Surgical intervention with lymphadenectomy and negative margins remained the most robust predictors of improved overall survival.