Induction chemotherapy and sequential concomitant chemo-radiation in locally advanced head and neck cancers: How induction-phase intensity and treatment breaks may impact on clinical outcomes

Aim: The purpose of the study was to assess outcomes of locally advanced head and neck (LAHNC) treated with induction chemotherapy (ICT) and subsequent concurrent chemo-radiation. Patients and Methods: A total of 71 LAHNC patients were treated with 2-3 cycles of docetaxel, cisplatin and 5-fluorouracil as induction chemotherapy and subsequent concurrent chemoradiation with weekly cisplatin or carboplatin. Definitive radiotherapy was delivered with intensity-modulated radiation and a simultaneous integrated boost approach up to a total dose of 70 Gy in 35 fractions to the macroscopic primary and nodal disease. Results: Actuarial 2-year OS, CSS, DFS, MFS, LC were 55.3% (95%CI=39.3-68.6), 58.6% (95%CI=41.9-72), 60.5% (95%CI=47.3-71.4), 87.3% (95%CI=76.2-93.5) and 74.7% (95%CI=61.5-83.9), respectively. On multivariate analysis undergoing to 3 vs. 2 cycles of TPF (HR=22.31; 95%CI=2.68-185.66; p=0.004) and radiotherapy treatment break >4 days (HR=1.28; 95%CI=1.06-1.55; p=0.01) negatively affected cancer-specific survival (CSS) with statistical significance. Achieving complete remission after ICT had a statistically significant impact on CSS (HR=0.9; 95%CI=0.01-0.54; p=0.009). Patients undergoing ICT with 3 cycles had more frequently treatment breaks compared to those submitted to 2 cycles (HR=1.36; 95%CI=1.06-1.73; p=0.01), and had statistically significant longer treatment break time (5.9+1.8 vs. 3+0.36; p=0.02). Conclusion: A shorter ICT phase may be a better option enhancing patients' tolerance during concurrent chemoradiation and affecting clinical outcomes.