351P - Stage I/II oropharyngeal carcinoma treated with surgery or RT at the Japan National Cancer Center Hospital East

Abstract

Background: According to the National Comprehensive Cancer Network guideline (ver. 1.2016), stage I/II oropharyngeal carcinoma (OPC) should be treated with surgery or definitive radiotherapy (RT). However, the appropriatetherapeutic strategy for OPC has not been elucidated yet. In addition, the optimal long-term therapeutic strategyshould be identified because head and neck cancers, including OPC, often have multiple primary cancers (simultaneous or metachronous) at high frequency. Methods: We retrospectively analyzed 81 cases of stage I/II OPC (limited to squamous cell carcinoma) treated with surgery or RT between January 2000 and December 2011 at the Japan National Cancer Center Hospital East. Results: The patients included 68 men and 13 women, whose median age was 68 years (range, 35–92 years). The median follow-up time was 1825 days. The cancer was stage I in 28 patients and stage II in 53 patients. The tumorinvolved the lateral wall in 43 patients, the anterior wall in 12, the superior wall in 19, and the posterior wall in 7. Surgery was performed for 62 patients; and RT, for 19 patients. Of the patients who underwent surgery, 44 underwent transoral surgery and 18 underwent open resection. Nine of the 18 patients who underwent open resection received a free flap. Only 1 of the patients treated with RT received proton beam therapy. The 5-year overall survival rates were 74.0% and 47.7%(p = 0.0199); the 5-year disease-specific survival rates,83.4% and 61.7% (p = 0.1158); and the 5-year local control rates, 70.7% and 57.4% (p = 0.1170) for the surgery and RT groups, respectively. Of the 81 cases, 43 (53.1%) were multiple primary cancers, of which 22 (27.2%) were in the head and neck region and all were metachronous. Conclusions: Initial surgery for stage I/II OPC is a useful therapeutic strategy considering the high incidence of multiple primary cancers. Legal entity responsible for the study: Japan National Cancer Center Hospital East. Funding: None Disclosure: All authors have declared no conflicts of interest.