We investigated the treatment outcomes of 371 patients with oropharyngeal squamous cell carcinoma who had received radical treatment at our institution between 1989 and 2018. The analyses were conducted by dividing the cases into three treatment periods: Period A: 1989–1999; Period B: 2000–2010 (when induction chemotherapy and chemoradiotherapy (CRT) were actively introduced); and Period C: 2011–2018 (when the human papillomavirus (HPV) status was actively investigated). The 5-year overall survival (OS) rates were 42.8% in Period A, 62.4% in Period B, and 72.4% in Period C (P < 0.0001). The 5-year OS by the HPV status was 85.4% in patients with HPV-positive cancer and 52.1% in patients with HPV-negative cancer (P = 0.0003). These treatment outcomes were comparable to those reported previously. With the increase in the number of cases of HPV-positive cancer and advancements in treatment techniques, the number of patients needing treatment by extended resection has decreased, and treatments such as CRT and minimally invasive surgery for preserving function are the mainstays of the currently used treatments.
