Chemotherapy alternated with radiotherapy in the treatment of advanced head and neck carcinoma: Predictive factors of outcome

Purpose: To investigate the impact of pretreatment and treatment- related factors on local-regional control and overall survival rates in advanced (III) and IV stage) head and neck cancer patients treated with alternating chemoradiotherapy, a selected group of 115 patients who had PS ≤ 1 and received a total dose of radiotherapy (RT) within ± 5% of that planned, was analyzed. Methods and Materials: Patients were planned to receive 4 cycles of chemotherapy (cisplatin and 5-fluorouracil) alternated with radiotherapy (60 Gy/30 fractions). However, mainly due to systemic toxicity, about 30% of the patients received less than 90% of the planned combined chemotherapy total dose (CCTD). Based on differences in treatment planning and delivery, patients were divided into two groups. For living patients, median follow-up is 34 months (range: 24-111 months). Results: At multivariate analysis, RT technique (p = 0.008), N stage (p = 0.010) and CCTD (p = 0.027) were independent predictors of LRC. Compared to each favorable subset (RR = 1), the relative risks of LRC failure were 2.18 (95% CI: 1.21- 3.91), 2.23 (95% CI: 1.11-4.50) and 2.23 (95% CI: 1.15-4.31) for patients without improved dose distribution and treatment delivery, with bilateral nodes or nodes greater than 6 cm, and with a CCTD lower than 90%, respectively. Regarding overall survival, only RT treatment was found to be an independent predictor (p = 0.037), with an RR of 1.61 (95% CI: 1.02-2.53) for patients without improved dose distribution and treatment delivery. Conclusion: Optimal delivery of RT dose is crucial in patients with advanced head and neck tumors, even if they receive chemotherapy as part of their treatment. This study also suggests that chemotherapy total dose may play a role in patient outcome, but this must be confirmed prospectively.