ESTRO 2024 - Abstract Book

S1293

Clinical - Head & neck

ESTRO 2024

Centre, Medical Oncology, London, Canada. 12 University of Ottawa, Otolaryngology – Head and Neck Surgery, Ottawa, Canada. 13 London Health Sciences Centre, Audiology, London, Canada. 14 Western University, Pathology, London, Canada. 15 London Health Sciences Centre, Otolaryngology – Head and Neck Surgery, London, Canada

Purpose/Objective:

Radiation therapy (RT) and transoral robotic surgery (TORS) are both curative-intent treatment options for early T stage oropharyngeal squamous cell carcinoma (OPSCC), but there are very few randomized studies comparing these approaches. In the setting of good-prognosis human papillomavirus (HPV)-related cancers, long-term outcomes are important to assess for late recurrences and late effects of treatment. Herein we report the final outcomes of the ORATOR trial, 5 years after completion of enrollment.

Material/Methods:

We randomly assigned 68 patients with T1-2, N0-2 (nodes up to 4 cm) OPSCC to RT (with chemotherapy if node positive) vs. TORS plus neck dissection (± adjuvant RT/chemoradiation based on pathology). The primary endpoint was swallowing quality of life (QOL) at 1-year, assessed with the MD Anderson Dysphagia Inventory (MDADI). Secondary endpoints included overall and progression-free survival (OS, PFS), adverse events (AEs), and other QOL metrics.

Results:

Sixty-eight patients were randomized (n=34 per arm) between August 2012 and June 2017. Median age was 59 years, 88% were male, and primary sites were 74% tonsillar vs. 26% base of tongue (BOT). The arms were well balanced for baseline factors. Median follow-up was 5.1 years. MDADI total scores were initially higher in the RT arm but converged by 5-years and were not significantly different across the whole time period (Figure 1; p=0.11). Five year total mean MDADI score was 85.3 in the RT arm vs. 84.6 in the TORS arm. EORTC QLQ C30 and H&N35 scores demonstrated differing QOL profiles, including worse dry-mouth in the RT arm (p=0.032) and worse pain scores in the TORS arm (p=0.002). There were no significant differences in neck functioning (measured by the Neck Dissection Impairment Index) or voice (measured by the Voice Handicap Index). Grade 2-5 toxicity rates were similar between arms (91% vs. 97%, respectively for the RT and TORS+ND arms, p=0.61), although constipation, neutropenia, hearing loss, and tinnitus were more common in the RT arm, and cough, trismus, and subjective weakness were more common in the TORS arm (all p<0.05). There were no differences in 5-year functional oral intake scores, with 95% in both arms on a total oral diet with no restrictions. Only 1 patient (TORS arm) had a feeding tube beyond 3 years, required due to a second primary head-and-neck cancer. There were no differences in OS or PFS by treatment arm in the whole population (5-year OS 84% vs. 85%, p=0.92, figure 2; 5-year PFS 84% vs. 82%, p=0.83, respectively for the RT and TORS+ND arms). In the p16+ subgroup, 5-year OS was 93% vs. 93%; p=0.98 and 5-year PFS 93% vs. 90%; p=0.66, respectively for the RT and TORS+ND arms).