Factors associated with positive surgical margins and overall survival in localized invasive vulvar squamous cell carcinoma: insights from the National Cancer Database (2004-2023).

We evaluated the prevalence, predictors, and survival impact of positive margins in localized invasive vulvar squamous cell carcinoma. Patients with localized invasive (pT1-T4, N0, M0) vulvar squamous cell carcinoma undergoing surgical excision were identified from the National Cancer Database (2004-2023). Margin status reflects the final pathologic assessment recorded as positive (microscopic or macroscopic residual tumor) or negative. Multivariable logistic regression was used to identify factors associated with positive margins. Overall survival was estimated using Kaplan-Meier and multivariable Cox models. Among 32,341 patients, 4,249 (13.1%) had positive margins. Factors independently associated with margin positivity included older age, later year of diagnosis, Black race, higher comorbidity burden, larger tumor size, higher grade, advanced T stage, treatment at non-academic centers, organ-sparing surgery. Positive margins were associated with worse overall survival (5-year: 59.6% vs 72.5%) and remained associated with increased mortality after adjustment for demographic, tumor, treatment, facility-related factors (aHR 1.30, 95% CI 1.23-1.37). Positive margins remain common in localized vulvar squamous cell carcinoma and are associated with worse overall survival, underscoring the need to optimize margin clearance, particularly in organ-sparing surgical approaches, while also considering other important factors such as tumor location, multifocality, re-excision, adjuvant therapy, and surgical expertise.