2705 - Outcomes of Patients with Unresectable Oral Cavity Cancers Treated with Definitive Concurrent Chemoradiotherapy: A 15-Years Single Institution Experience

10:45am - 12:00pm PT

Hall F

Screen: 24

POSTER

Presenter(s)

Rawan Alqahtani, MBBS - King Faisal Specialist Hospital and Research Centre, Riyadh, Riyadh

R. Alqahtani II¹, M. Aldehaim², N. M. Alrajhi¹, M. S. Anwar¹, and K. Shehzad¹; ¹King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia, ²King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia

Purpose/Objective(s): The optimal management of inoperable oral cavity squamous cell carcinoma (OC-SCC) remains largely unknown. Especially where surgical management is not a feasible option, either due tumor-related factors (such as unresectable extensive disease) or due to patient-related factors (such as patient preference, poor performance status or medical comorbidities). It is reasonable to consider whether nonsurgical modalities such as definitive concurrent chemoradiotherapy (CCRT) could be of value in such cases as an appropriate curative option or not. The aim of this study to review our 15-year experience at our institution in treating unresectable oral cavity cancer patients with definitive CCRT with or without induction chemotherapy.

Materials/Methods: It is a retrospective cohort study, where the Head and Neck cancer database at our institution was reviewed to identify all patients with primary OC-SCC at any stage or any subsite who treated with definitive CCRT between January 2009 and December 2023. The local control (LC), regional control (RC), distant control (DC) and overall survival (OS) were calculated by the Kaplan-Meier method. Multivariable analysis using Cox proportional hazards regression used to identify predictors of survival outcomes. All reported p-value < 0.05 considered statistically significant.

Results: 31 patients with locally-advanced OC-SCC were treated with definitive CCRT. The reason for non-operative management was due to: surgical unresectability (61.3%), patient declined surgery (32.3%) and medical inoperability (6.5%). The majority were in advanced T4a stage (67.7%) and N2c stage (48.4%). The predominant disease stage was IVA (77.4%). The most common primary sites were oral tongue (64.5%). Induction chemotherapy was administered to (77.4%) of them, primarily with Docetaxel, Cisplatin and 5-fluorouracil regimen (TPF) (50%). Post-induction chemotherapy response evaluation revealed a partial response in (81%) while progressive disease in (19%). Regarding the CCRT regimen, the majority received Cisplatin as the concurrent chemotherapy agent (60.7%) and the radiotherapy was delivered at mean total radiation dose of 67Gy (60-70 Gy). The median follow up was 25 months (9-90 months), while the median survival time was approximately 25.6 months. The 2-year (LC), (RC), (DC) and (OS) were (19%), (50%), (66%), and (50%) respectively. Performance status, T4b staging, IVB stage, local and regional failure were significantly impacted survival outcomes (p < 0.01). Feeding tube placement was required in (38.7%) of patients, and only (9.7%) underwent salvage surgery.

Conclusion: This study highlights poor survival outcomes and high failure rates in patients with unresectable OC-SCC treated with definitive CCRT, emphasizing the aggressive nature of the disease and the challenges in achieving durable local control with non-surgical approaches.