Background and Objectives: To investigate clinicopathological characteristics and survival outcomes of patients with buccal
cancer in Japan. Materials and Methods: This study was conducted using a database of 1055 patients with
oral cancers treated between 2010 and 2017 at 12 institutions in Japan. Ninety-two patients (8.7%) with primary buccal
cancer were extracted and clinicopathological characteristics and survival outcomes were compared between patients with buccal
cancers and patients with other
oral cancers. Results: Ages were significantly higher in the patients with buccal
cancer (73 years old vs. 69 years old). Buccal
cancer had less advanced cT stage and cN stage than other
oral cancers. Overall 5-year survival (OS) was 80.6%, and recurrence-free 5-year survival (RFS) of buccal
cancers was 67.8%, and there were no significant differences in survival compared with other
oral cancers in terms OS or RFS (5y-OS: 82.5%, 5y-RFS: 74.4%). However, patients with stage IV buccal
cancer showed poorer prognosis in terms of OS and RFS compared with the same stage patients with other
oral cancer. Advanced T stage was the only factor independently associated with both OS and RFS of patients with buccal
cancer in this study. Conclusions: Postoperative
radiotherapy or
chemoradiotherapy should be considered to improve survival outcome of buccal
cancer patients, especially for the patients with advanced primary site disease or a higher
cancer stage.