Clinical Outcome of Inoperable Locally Advanced Carcinoma of Oral Cavity Treated With Definitive Concurrent Chemoradiotherapy: A Retrospective Analysis From Tertiary Cancer Center

Abstract

The treatment of inoperable locally advanced oral cavity squamous cell carcinoma (OC-SCC) is challenging. In suitable patients, we prefer to treat them by definitive concurrent chemoradiotherapy (CTRT) with or without induction chemotherapy (IC). We intended to retrospectively evaluate the outcome of our cohort of inoperable OC-SCC treated with definitive CTRT.Data of 71 patients (Jan 2017-Jan 2020) of histopathologically proven inoperable OC-SCC treated with definitive CTRT with weekly cisplatin 40 mg/m2 with or without IC were retrieved from departmental archives. Radiotherapy (RT) was delivered with 3-dimensional conformal plan (70 Gray at 2 Gray per fractions delivered 5 days a week in two phases). Toxicities were evaluated using acute morbidity scoring criteria of RTOG. Response was evaluated as per WHO criteria. Loco-regional failure (LRF) and Progression free survival (PFS) were estimated from date of registration using Kaplan Meier method.Patient characteristics are summarized in Table 1. 48 patients (67.6%) received IC (Platinum+5 FU ± Taxane) q 3 weekly, median number of cycles was 3 (2-4). 64 (90%) patients received concurrent chemotherapy with median number of 5 cycles (4-6). Median RT dose was 70 Gray (50-70 Gray). Grade ≥ 3 skin toxicity, oral mucositis, dysphasia was noted in 7(9.9%), 11(15.5%) and 13 (18.3%) patients respectively. Median follow up duration was 15 months (3-52 months). Clinical response rate (CRR) at 1 month after completion of RT was 80%. Overall complete response, partial response, progressive disease and death at the time of last follow up were 37(52.1%), 21(29.6%), 11(15.5%), 2(2.8%) respectively. Age < 50 years was associated with poor outcome (odds ratio, 1.1; 95% CI 0.42-2.86). 3-month LRF rate was 32.4%. Median PFS was 11.4 months (5.3-32.4 months).Inoperable patients of OC-SCC with good performance status treated with definitive CTRT with or without IC yielded complete response in approximately half of patients with acceptable toxicity profile. Loco-regional failure remains the predominant mode of failure. Future research including studies on biomarkers for better patient selection and treatment personalization is warranted.