Comparison of postoperative radiotherapy and definitive radiotherapy for non-metastatic adenoid cystic carcinoma of the head and neck, a propensity score matching based on the SEER database.

Background: Treating patients with head and neck adenoid cystic carcinoma (HNACC) presents surgical problems in various scenarios. Limited studies explore definitive radiation's impact on patient survival, with inadequate data correlating it to postoperative radiotherapy. Using the Surveillance, Epidemiology, and End Results (SEER) program, we conducted an objective analysis to evaluate the impact of definitive radiation on the survival of HNACC patients without distant metastases, aiming to uncover its nuanced pros and cons.

Methods: This study conducted a comprehensive analysis of individuals diagnosed with HNACC within the SEER database from 2000 to 2023. Disease-specific survival (DSS) and overall survival (OS) were evaluated using diverse statistical methods. Propensity score matching (PSM) reduced covariate variations and selection biases, allowing for comparisons of postoperative and definitive radiotherapy groups.

Results: A total of 2,072 patients were encompassed within this study. The postoperative radiotherapy group yielded significant advantages in OS and DSS (P<0.001). In matched cohorts, the 5-year prognostic OS stood at 55% and 37%, respectively, while DSS figures were 65% and 46%, correspondingly. In advanced T4 cases, DSS differences lacked significance (P=0.42). Additionally, the outcomes of OS and DSS were notably influenced by variables such as T-stage, N-stage, tumor stage, and chemotherapy.

Conclusions: Surgical intervention remains a pivotal component of comprehensive treatment for patients diagnosed with operable HNACC. Definitive radiation is appropriate for less treatable situations, particularly in local advanced HNACC. Systemic treatment may assist HNACC patients at risk of distant metastases.