Phase II study of postperative radiotherapy (RT), cisplatin (Ci), and cetuximab (Ce) in resected bad prognostic head and neck squamous cell carcinoma (HNSCC): Toxicity analysis.

Abstract

e16051 Background: Despite toxic multimodal about 60% of resected HNSCC relapse. The addition of both Ce or Ci to RT improved overall survival of patients with HNSCC. Consequently, we designed a prospective phase II study, to evaluate the feasibility and efficacy of concomitant RT-Ci and Ce in bad prognostic resected HNSCC. Methods: Patients have resected HNSCC of the oral cavity , oropharynx, larynx or hypopharynx, and at least one of the following adverse prognostic factors: microscopically incomplete resection, >2 metastatic lymph nodes and/or >1 lymph node with extracapsular spread, vascular and/or lymphatic emboli, >2 perineural invasion, positive margins and pT4. All patients received: RT 70-72Gy in 7 weeks concurrent with Ce 250mg/m² weekly (6-7 weeks), after a loading dose of 400mg/m², and Ci 75mg/m² every 3 weeks x3 cycles. The primary endpoint is the 2 years disease-free survival. Results: 45 patients (35 Male) were enrolled, and 44 were evaluable for toxicity. Median age was 56 years (27-70). The tumor site was oral cavity (21), oropharynx (17), hypopharynx (3) and larynx (4). 39% of the patients had stage T2, 14% stage T3 and 27% stage T4. The nodal status was 0-2b in 80% of cases. The main adverse prognostic factors were the nodal involvement and microscopical positive resection (80% of patients). The RT-Ce-Ci regimen was discontinued in 11 cases including 7 due to toxicity. Among the 352 cycles (ie Ce+/-Ci) initially planned, 301 were delivered. Cutaneous and mucosal toxicity were the most common grade 3/4 side effects, accounting for 35% and 33%, respectively, and remained manageable. Grade 3 lymphopenia has been noted in 25% of cases. No treatment-related death was recorded. Conclusions: The triple association of RT-Ce-Ci appears to be safe and feasible in patients with bad prognostic resected HNSCC. The toxicity profile is comparable to that reported for RT-Ci or RT-Ce alone. Longer follow-up is required to evaluate the impact of addition of Ce to RT-Ci on survival.