Investigation of the clinicopathological features of vulva cancer: A retrospective survey of the JGOG Net Work study.

e17029 Background: Vulvar cancer is a rare malignancy in women. During the past 30 years, large surveys of vulva cancer have not been performed in Japan. We therefore conducted a multicenter study to clarify the clinicopathological features of vulva cancer in Japan. Methods: In this multicenter retrospective cohort study, the clinical data of patients with vulva cancer were surveyed. The medical records of patients with vulvar cancer patients treated between 2001 and 2010 were retrospectively reviewed after obtaining approval from the Institutional Review Board of each institution. Survival analysis was performed using Kaplan-Meier curves. The effects of the clinical factors on overall survival were investigated using a Cox regression model. Results: A total of 1082 patients treated in 108 centers were studied. The median age was 72 years (range, 20 to 96). The disease stage was stage I in 415 patients (38.3%), stage II in 249 (23%), stage III in 255 (23.6%), and stage IV in 163 (15.1%) (FIGO 2009). The diagnosis was squamous cell carcinoma in 779 patients (72%), Paget’s disease in 158 (14.6%), adenocarcinoma in 63 (5.8%), and others in 82 (7.6%). Positive lymph nodes were found in 237 patients (21.9%). The median tumor diameter was 35 mm (range, 1 to 180). The 5-year overall survival was 86% in stage I, 74.7% in stage II, 48.2% in stage III, and 39.3% in stage IV (P < 0.001), and that according to histology was 63.9% in squamous cell carcinoma, 57.1% in adenocarcinoma, 79.7% in Paget’s disease, and 85.4% in others. The hazard ratio was 0.51 in patients with a histology of Paget’s disease or others (vs. squamous cell carcinoma or adenocarcinoma; P = 0.001; 95% CI, 0.35-0.75), 2.14 in patients with a the number of positive lymph nodes 2 or more (vs. 0 or 1; P < 0.001; 95% CI, 1.50-3.05), 2.10 in patients with a tumor diameter of ≥35mm (vs. < 35mm; P = 0.001; 95% CI, 1.36-3.25). Conclusions: Treatment outcomes in Japanese patients with vulvar cancer were similar to those reported previously. However, squamous-cell carcinoma, adenocarcinoma, positive lymph nodes, and bulky tumors were associated with poor outcomes. Multidisciplinary treatment might be required in patients with these characteristics. Clinical trial information: UMIN000017080.