Assessing Rates of Positive Surgical Margins After Standard Excision of Vulvar Melanomas

Abstract

BACKGROUND Vulvar melanoma is a rare malignancy with frequent recurrence and poor prognosis. National guidelines recommend wide local excision of these tumors with allowances for narrower margins for anatomic and functional limitations, which are common on specialty sites. There is presently a lack of data of margin positivity after standard excision of vulvar melanomas. OBJECTIVE We aim to evaluate the rate of positive margins after standard excision of vulvar melanomas. MATERIALS AND METHODS Retrospective cohort study of surgically excised vulvar melanomas from the NCDB diagnosed from 2004 to 2019. RESULTS We identified a total of 2,226 cases. Across surgical approaches and tumor stages, 17.2% (Standard Error [SE]: 0.8%) of cases had positive surgical margins. Among tumor stages, T4 tumors were most commonly excised with positive margins (22.9%, SE: 1.5%). On multivariable survival analysis, excision with positive margins was associated with significantly poorer survival (Hazard Ratio 1.299, p = .015). CONCLUSION We find that positive margin rates after standard excision of vulvar malignancies are higher than for other specialty site melanomas. Our data suggest that use of surgical approaches with complete margin assessment may improve local control and functional outcomes for patients with vulvar melanoma as they have for patients with other specialty site melanomas.