Toxicity and efficacy of cetuximab associated with several modalities of IMRT for locally advanced head and neck cancer.

Purpose: Intensity-modulated radiation therapy (IMRT) has shown its interest for head and neck cancer treatment. In parallel, cetuximab has demonstrated its superiority against exclusive radiotherapy. The objective of this study was to assess the acute toxicity, local control and overall survival of cetuximab associated with different IMRT modalities compared to platinum-based chemotherapy and IMRT in the ARTORL study (NCT02024035).

Patients And Method: This prospective, multicenter study included patients with epidermoid or undifferentiated nasopharyngeal carcinoma, epidermoid carcinoma of oropharynx and oral cavity (T1-T4, M0, N0-N3). Acute toxicity, local control and overall survival were compared between groups (patients receiving cetuximab or not). Propensity score analysis at the ratio 1:1 was undertaken in an effort to adjust for potential bias between groups due to non-randomization.

Results: From the 180 patients included in the ARTORL study, 29 patients receiving cetuximab and 29 patients treated without cetuximab were matched for the analysis. Ten patients (34.5%) reported acute dermal toxicity of grade 3 in the cetuximab group versus three (10.3%) in the non-cetuximab group obtained after matching (P=0.0275). Cetuximab was not significantly associated with more grade 3 mucositis (P=0.2563). There were no significant differences in cutaneous or oral toxicity for patients treated with cetuximab between the different IMRT modalities (P=1.000 and P=0.5731, respectively). There was no significant difference in local relapse-free survival (P=0.0920) or overall survival (P=0.4575) between patients treated with or without cetuximab.

Conclusion: Patients treated with cetuximab had more cutaneous toxicities, but oral toxicity was similar between groups. The different IMRT modalities did not induce different toxicity profiles.