Prognostic impact of bridge or neoadjuvant induction chemotherapy in patients with resected oral cavity cancer: A nationwide cohort study

Background: While surgery remains the primary treatment for oral squamous cell carcinoma (OCSCC), induction chemotherapy (IC) can be used as a bridging or neoadjuvant therapy. This nationwide study in Taiwan examines the survival outcomes of OCSCC patients who received IC before surgery. Methods: We analyzed data from 29,891 patients with OCSCC. Of these, 29,058 initially underwent surgery (OP group), whereas 833 received IC before surgery (IC + OP group). A propensity score (PS)-matched analysis (4, 1 ratio, 3260 vs. 815 patients) was performed considering tumor subsite, sex, age, Charlson comorbidity index, clinical T1-T4b tumors, clinical N0-3 disease, and clinical stage I-IV. Results: In the PS-matched cohort, the 5-year disease-specific survival (DSS) and overall survival (OS) rates were 65% and 57%, respectively. When comparing the OP and IC + OP groups, the 5-year DSS rates were 66% and 62%, respectively (p = 0.1162). Additionally, the 5-year OS rates were 57% and 56%, respectively (p = 0.9917). No significant intergroup differences in survival were observed for specific subgroups with cT4a tumors, cT4b tumors, cN3 disease, pT4b tumors, and pN3 disease. However, for patients with pT4a tumors, the OP group demonstrated superior 5-year outcomes compared to the IC + OP group, with a DSS of 62% versus 52% (p = 0.0006) and an OS of 53% versus 44% (p = 0.0060). Notably, patients with cT2-3, cN1, and c-Stage II disease in the IC + OP group were significantly more likely to achieve pT0-1 status (p < 0.05). Conclusions: Following PS matching, the IC + OP group generally exhibited similar prognosis to the OP group. However, for pT4a tumors, the OP group showed superior 5-year outcomes. While IC may not universally improve survival, it could be advantageous for patients who respond positively to the treatment.