Presurgical chemotherapy for HPV positive oropharyngeal squamous cancers.

e18022 Background: Human Papilloma Virus (HPV) related tumors of the oropharynx have been associated with an increase in survival for patients. Induction chemotherapy followed by surgery can maintain survival in select oropharyngeal squamous cancers (OPSCC) while avoiding radiotherapy, reducing overall treatment morbidity and deescalating treatment. In this study, all patients underwent planned induction chemotherapy and surgery with selective use of adjuvant, postoperative chemoradiotherapy (CRT). Methods: From 2008 to 2019, sixty-one patients with HPV positive oropharyngeal cancers were treated with induction chemotherapy followed by selective neck dissection and transoral resection of their primary disease. All patients were without distant metastasis at presentation. There were 56 men and 5 women with a mean age of 61 years. All patients were HPV+ via direct HPV immunohistochemistry (ISH). 44 patients were either never or long-term former smokers. 56 patients had primary disease in the tonsil, 4 in the base of tongue, 1 in the soft palate. 57/61 patients had nodal metastasis on presentation. All patients received induction chemotherapy inclusive of Cisplatin and Docetaxel (TP) of 2-4 cycles. 12 patients received either 5-FU or Cetuximab as well. Adjuvant chemoradiotherapy was deferred if patients had complete response (CR) to induction chemotherapy at the primary and neck, or with CR in the neck and partial response (PR) at the primary with negative surgical margins. Mean follow-up time was 3.2 years. Results: A CR to induction chemotherapy was achieved in 35/61 (57%) of patients. There were no treatment deaths or chemotherapy-related hospital admissions. 13/61 (21%) underwent adjuvant chemoradiotherapy. 14/61 (23%) patients with PR deferred chemoradiotherapy. 5 patients deferred chemoradiotherapy due to CR in the neck, 9 patients refused recommended chemoradiotherapy. 9/61 (15%) patients suffered recurrence of disease. Of these, 6 (67%) are currently free of disease (NED) as of most recent follow-up. Overall survival in this cohort was 95% (58/61), disease-free survival in this cohort was 85% (52/61). Smoking status (active vs former/non) was predictive of overall survival (p = .019). In total, 47/61 (77%) of patients were NED without undergoing chemoradiotherapy. Conclusions: This is a select series of patients with limited follow-up. However radiotherapy was avoided in most patients without sacrificing survival in this group with good overall prognosis. Appropriate use of induction chemotherapy and surgical management of oropharyngeal cancers is dependent upon the resectability of the primary on initial presentation (lack of significant local invasion). This study shows, for select HPV positive oropharyngeal cancers, induction chemotherapy followed by selective, trans-oral surgery allows for improved survival while avoiding the additional morbidity of (chemo)radiotherapy.