Vulvar cancer is a rare gynecologic cancer with limited guideline consensus, particularly for locally advanced disease. This study aimed to explore prognostic factors and optimize treatment strategies for vulvar cancer.

We performed a multicenter, cross-ethnic retrospective study including pathologically confirmed vulvar cancer cases from the Chinese multicenter registry (2003−2023) and the SEER database(2004–2021). Patients younger than 20 or lost to follow-up were excluded. Kaplan-Meier analysis was used to compare survival, and prognostic factors were assessed using multivariate Cox regression. Baseline characteristics were balanced using inverse probability of treatment weighting (IPTW). Overall survival (OS) was the primary endpoint.

A total of 19,682 patients were analyzed (604 Chinese, 19,078 SEER). Surgery was independently associated with improved OS in both cohorts (Chinese: HR = 0.46, 95 %CI: 0.33–0.64; SEER: HR = 0.43, 95 %CI: 0.41–0.46; both p < 0.001). Among patients with locally advanced disease, surgery remained protective (Chinese: HR = 0.43, 95 %CI: 0.27–0.69; SEER: HR = 0.52, 95 %CI: 0.47–0.57; both p < 0.001), and this effect persisted after IPTW adjustment (Chinese: HR = 0.38; SEER: HR = 0.50; both p < 0.001).

Our large multicenter analysis demonstrated that surgery significantly improves survival in vulvar cancer, including locally advanced cases, providing important evidence for treatment optimization.