A 34-year clinical study of oral squamous cell carcinoma in female patients in our department − Survey on trends in radical surgical cases in a single institution −

: The number of patients with oral cancer is tending to increase in Japan. It has been reported that oral cancer is most highly prevalent in men 60 years or older. However, the numbers of affected females and young patients have tended to increase in recent years. Between 1982 and 2016, a retrospective study was conducted on 936 primary cases of oral squamous cell carcinoma treated by curative surgery in Tokyo Dental College Chiba Hospital, and a clinical study on the trends of female patients was conducted. Female patients during the same period accounted for 388 cases （41.5% of the total）. The ratio of female patients with oral squamous cell carcinoma increased significantly during the 34 years. The male-female ratio was 1.41:1. The mean age of female patients was 67.3 years. The tongue was the most frequency encountered primary site among female patients, accounting for 46.9% of cases. Well-differentiated type was most common, accounting for 75.8% on histopathological differentiation typing. The incidences of stages I, II, III and IV oral squamous cell carcinoma according to the TNM staging system were 27.1%, 30.7%, 22.9%, and 19.3%, respectively. As for life history, 36.3% of the female patients had drinking habits, and the sake index was 22.8. The ratio of smoking habits was 28.1%, and the Brinkman index was 141.4. The 5-year disease-free survival rate was 77.7%, and the 5-year overall survival rate was 86.4%. Although the survival rate of female patients did not differ significantly from that of male patients, outcomes were slightly more favorable among female patients than male patients.