Phase II study: Induction chemotherapy & transoral surgery as definitive treatment (Tx) for locally advanced oropharyngeal squamous cell carcinoma (OPSCC): An update and retrospective review of non-study patients.

Abstract

e18549 Background: The standard of care for OPSCC includes chemoradiation (CRT) or surgery with adjuvant radiation (RT). However, RT is associated with significant life long morbidity. We assessed the efficacy of a two-drug induction regimen, followed by transoral robotic assisted surgery (TORS) & neck dissection for locally advanced OPSCC. Methods: This is an IRB approved single-arm phase II study for untreated stage III or IVA (AJCC 7th edition) OPSCC patients (pts) with an ECOG < 2 and GFR > 50 cc. Induction cisplatin 75 mg/m2 and docetaxel 75 mg/m2 was administered every 21 days for 3 cycles. Patients then underwent TORS and neck dissection(s). At post-op visits, flexible laryngoscopy, blood tests, and imaging with PET/CT and/or MRI were done. Short and long term toxicity, progression-free survival, overall survival, and quality of life (QOL) were evaluated in all pts. Results: Twenty oropharyngeal pts were treated, 19 were male, 17 were Caucasian, and 19 were HPV+. Median age at dx was 57. Three pts were stage III, and 17 were stage IVA. Pathologic CR at the primary site occurred in 15 pts and CR among LN neck dissections occurred in 13 pts. Four pts were given dose-reduced chemo and 1 pt was changed to carboplatin per protocol because of renal dysfunction. Pre vs post tx QOL scores did not change. At a mean follow-up of 40.7 months (range 13 to 55), 18 pts are alive and NED. Three pts recurred a mean of 2.2 mos after surgery, and were treated with salvage CRT. Two pts died of metastatic disease, the third is alive and well. All 3 pts had positive LN (9 LN, 3 LN and 1 LN) at surgery. A fourth pt had 12 pos LN and received radiation. He has not recurred. A retrospective review of an additional 20 twenty pts treated in the same way, were also reviewed for efficacy. Mean age was 61.5. Two pts died of metastatic disease. Twenty pts have been followed for > 13 mos (17 are alive and well, 2 died, and 1 LFU), and their mean follow-up is 43.5 mos. Conclusions: Cisplatin + docetaxel followed by TORS & neck dissection(s) appears to be an effective model for the definitive treatment for OPSCC, while avoiding the adverse effects of RT. Clinical trial information: NCT02760667.