Postoperative adjuvant chemoradiotherapy versus postoperative adjuvant radiotherapy for head and neck squamous cell carcinoma with adverse pathology: a systematic review and meta-analysis

Objectives: Postoperative chemoradiotherapy has arisen as an adjuvant option for head and neck cancers, but its superiority to radiotherapy alone in patients with adverse pathologic factors is not yet well defined. We aimed to perform an updated meta-analysis comparing outcomes in head and neck cancer patients with adverse pathologic factors who underwent postoperative chemoradiotherapy and radiotherapy alone.

Methods: We systematically searched PubMed, Scopus and the Cochrane Central Register of Controlled Trials for Randomised Controlled Trials (RCTs) in patients submitted to postoperative adjuvant therapy with radiotherapy alone or chemoradiotherapy.

Results: We included 8 studies with a total of 2376 patients, of whom 1183 (49.8%) underwent postoperative chemoradiotherapy. In pooled analysis, overall survival (HR=0.86; 95% CI 0.76‒0.98; p=0.64; I²=0%) and disease-free survival (HR=0.85; 95% CI 0.75‒0.96; p=0.64; I²=0%) were shown to be superior in patients undergoing combined therapy. Chemoradiotherapy was also associated with significantly lower locoregional recurrence. However, there was no significant difference in distant metastasis occurrence between both groups. In an analysis of the extracapsular extension subgroup, the overall survival (OR=3.12; 95% CI 1.76-5.51; p=0.78; I²=0%), disease-free survival (OR=3.44; 95% CI 2.00‒5.91; p=0.68; I²=0%), and locoregional control (OR=1.86; 95% CI 1.16‒2.99; p=0.98; I²=0%) were better in the postoperative adjuvant chemoradiotherapy branch over radiotherapy alone.

Conclusion: The results of our meta-analysis suggest that postoperative adjuvant chemoradiotherapy in patients with head and neck cancer with adverse pathologic factors favors a superior survival and a better locoregional control compared to postoperative radiotherapy alone, despite not affecting the ocurrence of distant metastasis.