Association of HPV and p16 Status with Cetuximab plus Radiotherapy in Locally Advanced Head and Neck Cancer
The randomized phase 3 IMCL-9815 trial demonstrated that the addition of cetuximab to radiotherapy improved locoregional control (LRC) and overall survival (OS) in patients with locoregionally advanced squamous-cell carcinoma (SCC) of the head and neck (Bonner J, et al. ESMO 2014: Abstract 993PD).
In this retrospective analysis of the IMCL-9815 trial, treatment outcomes were analyzed by human papillomavirus (HPV) infection and p16 status; a secondary objective was to determine the impact of adding cetuximab to radiotherapy on radiotherapy-related mucositis and dysphagia in patients with p16-positive and p16-negative oropharyngeal cancer.
For this analysis, 311 of the 424 patients in the intent-to-treat population were evaluable for p16 status, of which 75 cases were found to be p16-positive oropharyngeal cancer. Overall, 63 patients were evaluable for HPV status, of which 49 were HPV positive and 14 were HPV negative. In terms of the effect of cetuximab on tolerability, the addition of cetuximab to radiotherapy did not alter the time to onset or the duration of resolution of mucositis and dysphagia compared with radiotherapy alone in patients with oropharyngeal cancer, irrespective of p16 status. With regard to treatment effect on clinical outcomes, the addition of cetuximab to radiotherapy improved LRC and OS compared with radiotherapy alone in the HPV-positive and HPV-negative subgroups.
These results indicate that p16 tumor status is a strong prognostic factor in locally advanced SCC of the head and neck. Bonner and colleagues concluded that patients with p16-positive oropharyngeal cancer have a favorable prognosis, regardless of HPV status; the addition of cetuximab to radiotherapy did not alter the time to onset or the duration of resolution of mucositis or dysphagia in patients with oropharyngeal cancer, regardless of their p16 status.