Definitive chemoradiation for oropharyngeal squamous carcinomas: Outcomes with intensity-modulated radiation therapy using simultaneous integrated boost, in a majorly p16 negative cohort.

Abstract

The literature on modern-era outcomes of oropharyngeal squamous carcinoma (OPSCC) in India is limited. We analyzed records of consecutive patients with OPSCC treated using a curative SIB IMRT regimen of 66 Gy/30#/6 weeks. One hundred fifteen patients from July 2011 to December 2018 were analyzed. Twenty of 69 patients tested positive for p16. In p16 positive patients, the K-M probability of being disease free and alive at 2 years, with at least one follow-up 3 months after treatment, was 83% (median not reached) compared with 48% if p16 was unknown/negative. Patients staged as IVB p16 negative had a 2-year DFS of 25%. Patients unfit for cisplatin and consequently received other agents had 2-year DFS estimated at 20%. Intensity-modulated radiation therapy (IMRT) with simultaneous integrated boost (SIB) and concurrent chemotherapy was feasible, with toxicity and disease control comparable to available literature. AJCC Stage IVB p16 negative disease had notably poor outcome.