Significance of definitive concurrent chemoradiotherapy for vulvar cancer: a Japanese Gynecologic Oncology Group nationwide survey study

Objective: This study aimed to show the results of radical radiation therapy (RT) and concurrent chemoradiotherapy (CCRT) for vulvar cancer (VC) based on data from a Japanese nationwide survey.

Materials and methods: We collected data from 108 institutions on cases of VC diagnosed between January 2001 and December 2010. Patients with histologically proven squamous cell carcinoma and adenocarcinoma with curative intent were selected, and 172 patients with VC were included in this study. The collected data were analyzed for overall survival (OS) using the Kaplan-Meier method. Univariate and multivariate analyses were performed to examine the prognostic factors for patients with VC.

Results: The median follow-up period was 16.8 (range; 3.2-154.8) months. Fifty-five patients received CCRT, and 117 patients received RT alone. The 2-year OS rates (95% confidence interval [CI]) for stages I, II, III, and IV were 77.9% (55.8-100.0), 71.9% (53.8-89.9), 55.4% (42.5-68.3), and 41.5% (27.3-55.7) respectively. Univariate analyses showed that the FIGO stage (p = 0.001), tumor diameter (p = 0.005), and lymph node (LN) status (p = 0.001) were associated with OS. The concurrent use of chemotherapy resulted in a significantly longer OS in Stage III (p = 0.013). Multivariate analysis showed that the hazard ratios (95% CI) for tumor diameter, positivity for LN metastasis, and RT alone (no concurrent chemotherapy) were 1.502 (1.116-2.021), 1.801 (1.287-2.521), and 1.936 (1.187-3.159), respectively.

Conclusions: Our analysis revealed that CCRT should be recommended, especially for Stage III VC patients. Further studies are warranted to determine who benefits from CCRT, considering primary tumor size and LN status. The study was registered at the University Hospital Medical Information Network (protocol number: UMIN000017080) on April 8th, 2015.