Elective neck irradiation does not improve regional control or survival in pT3-T4N0 oral cavity SCC after high-yield neck dissection: A retrospective multicenter analysis.

OBJECTIVES

In pT3-T4 oral cavity squamous cell carcinoma (OCSCC), standard management includes surgical resection with elective neck dissection (END), frequently followed by postoperative radiotherapy (PORT). While PORT is commonly administered for advanced primary tumors, the benefit of elective neck irradiation (ENI) in patients with a pathologically node-negative (pN0) neck after adequate high-yield END remains uncertain. This study evaluated whether ENI improves regional control or overall survival (OS) in this setting.

METHODS

We conducted a retrospective multicenter cohort study of adults with pT3-T4N0 OCSCC treated between 2004 and 2024 at two tertiary referral centers. All patients underwent high-yield END (≥ 18 lymph nodes). Patients were stratified by PORT field: no PORT, PORT to the primary site only, or PORT to the primary site plus ENI. The primary outcome was regional recurrence-free survival (RFS); secondary outcomes included OS. Survival was analyzed using Kaplan-Meier methods and Cox proportional hazards modeling.

RESULTS

A total of 156 patients were included. Over a median follow-up of 91 months, regional recurrence occurred in 6.4% of patients. There was no significant difference in RFS between patients who received ENI and those who did not (log-rank p = 0.16), nor in OS (log-rank p = 0.30). Stratification by radiotherapy field revealed no differences in RFS (log-rank p = 0.33) or OS (log-rank p = 0.51). In multivariable analysis, ENI was not independently associated with regional recurrence. Tumor stage (pT3 vs pT4a) did not influence regional control or survival.

CONCLUSIONS

In patients with pT3-T4N0 OCSCC who undergo high-yield END, ENI is not associated with improved regional control or OS. These findings support a selective, risk-adapted PORT strategy that omits routine neck irradiation in appropriately staged patients, potentially reducing treatment-related morbidity without compromising oncologic outcomes. Prospective multicenter studies are warranted to confirm these results.