Effect of multimodal-treatment for oropharyngeal squamous cell carcinoma with or without human papilloma virus infection―Report from Japan cooperative study group for basic research in head and neck cancer

The recent increase in the incidence of oropharyngeal cancer in the USA and northern Europe has been attributed to human papillomavirus (HPV) infection. Because the carcinogenic mechanism of HPV related oropharyngeal cancer (OPC) is different from that of other OPC, biological malignancy and treatment effects are considered to be different between the two groups. We performed a prospective study in the Japanese cooperative study group for basic research in head and neck cancer (JCSG-BRHNC) to compare the effects of first-line treatment between HPV positive or negative stage III and IV OPC. From May 2014 to March 2016, 92 patients were enrolled by 18 institutions in the whole country. Sixty-five patients (71%) were HPV-positive in the PCR. We examined the effects of primary treatment in a prognosis investigation conducted one year after registration. The results showed that 60 of the 65 HPV-positive cases successfully achieved complete response(CR), and the primary treatment success ratio was 92.3% as the ratio of CR cases without recurrence or metastasis within one year. In comparison, 15 cases (57.7 %) of 26 HPV negative patients successfully achieved CR. The effect of chemoradiotherapy was high, and even cetuximab combination radiotherapy(BRT) showed enough effects for HPV-positive cases. Also, induction chemotherapy (IC) was successful and all cases achieved CR in RT singularity cases. These results will provide a useful reference when examining clinical trials that lower the intensity of treatment for HPV-positive cases.