Omission of Radiotherapy after surgery may reduce survival in advanced Oral Cancer: JAMA

The 2015 participant user file from the National Cancer Database (NCDB) was analyzed. Patients with standard keratinizing OSCC who underwent up-front definitive surgery were included. To obtain a homogenous cohort with unambiguous pathological indications for PORT, patients with pathological stage III or IV OSCC were included. Patients with pathological T1-2N1 disease were excluded.

A total of 89,402 patients diagnosed with OSCC were identified, of whom 7084 patients met inclusion criteria. All patients had American Joint Committee on Cancer (AJCC) pathological stage III (n = 820, 12%) or stage IV (n = 6264, 88%) disease.

A total of 2140 patients (30%) did not undergo any PORT. Reasons for omission included: 1614 (76%) for whom PORT was listed as not part of the first course of treatment, 346 (16%) who refused recommended PORT, 103 (5%) for whom PORT was contraindicated owing to patient risk factors, and 68 (3%) for whom radiation was recommended and not given without documented reason.

For analysis, 56 Gy or lower was considered incomplete total PORT dosing. Receipt of PORT higher than 56 Gy as compared with no PORT was significantly associated with improved overall survival in every age category when adjusting for relevant covariates. Despite this, PORT omission increased for each decade from 60 to 90 years. Age younger than 65 years and distance less than 25 miles from the treatment facility were the most significant sociodemographic factors associated with receipt of PORT.

Nearly one-third of patients included in this study, and more than 40% of patients older than 70 years, did not receive PORT despite clear National Comprehensive Cancer Network recommendations. Importantly, this omission was associated with decreased survival in every age category. While the addition of PORT adds treatment-related morbidity and requires an individualized informed risk and benefit assessment, there appears to be substantial, and possibly preventable, mortality related to PORT omission.

While PORT omission was associated with decreased survival, it is important to recognize that its usage may be a surrogate for differences in access to care. Omission of PORT in the present study was associated with older age and distance from the treatment facility. Omission may therefore be related to the extended duration of current PORT regimens (6-7 weeks) combined with long travel distances and physical challenges related to advancing age. These factors could serve as targets for further investigation with potential interventions focusing on education, accessibility, and care coordination.

This study suggested that PORT is inappropriately omitted in a large portion of patients with advanced-stage OSCC, and this omission is associated with reduced patient survival and requires further investigation.

Source: doi:10.1001/jamaoto.2021.1744