Investigation of clinicopathological features of vulvar cancer in 1068 patients: A Japanese Gynecologic Oncology Group (JGOG) nationwide survey study.

Abstract Objective Vulvar cancer is a rare malignancy in the aging population, and optimizing treatment strategies requires large-scale investigation of the clinicopathological features of this disease. In Japan, no such surveys have been conducted in the past 30 years. This large-scale retrospective multi-center study aimed to examine the clinicopathological features of vulvar cancer in Japan. Methods Upon obtaining ethical approval by the participating institutions' review boards, the medical records of patients with vulvar cancer, who were treated between 2001 and 2010 were reviewed. The impact of clinicopathological factors on overall survival (OS) was investigated using a multivariate Cox regression model. Results After applying the inclusion and exclusion criteria, 1068 patients treated in 108 centers were included. The median age was 72 years. The disease was in stage I in 402 patients (37.6%), stage II in 249 patients (23.3%), stage III in 252 patients (23.6%), and stage IV in 165 patients (15.4%). Squamous cell carcinoma, Paget's disease, adenocarcinoma, and other diseases were diagnosed in 773 (72.4%), 154 (14.4%), 59 (5.5%), and 82 (7.7%) patients, respectively. Positive inguino-femoral lymph nodes were found in 265 (24.8%) patients. The 5-year OS rate for stage I, II, III, and IV vulvar cancer were 85.6%, 75.1%, 48.8%, and 40.0%, respectively. Conclusion Our study shows that advanced age, disease stage, histological diagnosis, tumor diameter, and lymph node metastases significantly affect the OS of patients with vulvar cancer in Japan.