Abstract
The incidence of oral cancer has been increasing in Japan and it is reported to have the highest prevalence in men aged 60 years or older. However, the prevalence in young patients has increased in recent years.
This retrospective study examined 36 patients who were less than 40 years of age （young patients） and who had tongue squamous cell carcinoma that was treated primarily at Tokyo Dental College from 1997 to 2016. Among a total of 369 patients with tongue squamous cell carcinoma treated in our department during this period, young patients comprised 9.8%. The proportion of young patients increased over the 20 years, and the male-female ratio of young patients was 1.25：1. On histopathologic examination, the most common type was the well-differentiated type, which accounted for 75.0%. The incidence of TNM stage Ⅰ, Ⅱ, Ⅲ, and Ⅳ was 41.7%, 19.4%, 22.2%, and 16.7%, respectively. As risk factors for oral cancer, drinking habit, smoking habit, and mechanical irritation were reported by 38.9%, 41.7%, and 91.7% of the young patients, respectively. The 5-year overall and disease-free survival rates were 88.2% and 82.6%, respectively. Although the survival rate of young patients did not differ significantly from that of older patients, the outcomes were slightly more favorable in young patients than in older patients.
