Benefit From Postoperative Radiotherapy Improves With Increasing Tumor Size Among Patients with Oral Cavity Squamous Cell Carcinoma

Postoperative radiotherapy was associated with improved overall survival among patients with pT4aN0 oral cavity squamous cell carcinoma, and the relative survival benefit improved with increasing tumor size, according to a retrospective analysis.

Any oral cavity squamous cell carcinoma tumor with mandibular involvement “are upstaged to pT4a regardless of their size,” Randall J. Harley, MD, University of Pennsylvania, Philadelphia, and coauthors wrote. Additionally, “small tumors with boney invasion, which would otherwise be classified as pT1-2, are recommended for the locally advanced treatment pathway to receive administration of postoperative radiotherapy.” This analysis was conducted to determine whether the therapeutic benefit of postoperative radiotherapy changes with respect to tumor size for patients with pT4aN0 oral cavity squamous cell carcinoma.

This analysis included patients who underwent mandibulectomy for treatment-naïve pT4aN0 oral cavity squamous cell carcinoma with negative surgical margins from the US National Cancer Database between January 1, 2004, and December 31, 2019. Of the 3268 patients included, 1851 received postoperative radiotherapy and 1417 did not. Multivariate analysis adjusted for age, insurance status, Charlson Comorbidity Index score, tumor site, tumor grade, tumor size, and postoperative radiotherapy.

According to the analysis, postoperative radiotherapy was associated with improved overall survival, which trended upward as the tumor size increased. As Dr Harley et al wrote, “The larger the tumor, the greater the survival advantage associated with the use of [postoperative radiotherapy].” For those patients with tumors >4 cm (n = 1068), the adjusted hazard ratio (aHR) in favor of postoperative radiotherapy was 0.63. For patients with tumors >2cm but ≤4cm (n = 1774), the aHR was 0.76. For patients with tumors <2cm (n = 426), the aHR was 0.81.

Dr Harley et al concluded, “These findings suggest that tumor size should be considered in guidelines for [postoperative radiotherapy] administration in this patient population.”

Source:

Harley RJ, Iheagwara UK, Faraji F, et al. Postoperative radiotherapy and survival in oral cavity squamous cell carcinoma with mandibulectomy. JAMA Otolaryngol Head Neck Surg. Published February 1, 2024. doi:10.1001/jamaoto.2023.4444