Efficacy and tolerance of carboplatin-cetuximab in patients with metastatic or recurrent head and neck squamous cell carcinoma unfit for extreme regimen.

Abstract

6539 Background: Head and neck squamous cell carcinoma (HNSCC) is the fourth cause of death by cancer in France. For metastatic patients, the standard first line treatment is the EXTREME regimen. However, a lot of these patients have a poor performance status (PS) and/or several comorbidities making them unfit for this regimen. We have treated them with carboplatin and cetuximab (simplified EXTREME regimen) since 2007. The aim of this study is to assess the efficacy and tolerance of this regimen in this frail population. Methods: We retrospectively reviewed the medical charts of all patients treated with simplified EXTREME regimen for recurrent or metastatic HNSCC in three French academic hospitals between 2007 and 2017. The primary endpoint was overall survival (OS) and secondary endpoints were progression free survival (PFS), overall response rate (ORR), identification of prognostic factors, and toxicity. Results: 103 patients were included with a median age of 63 y.o., 60% had a PS 0-1 and 40% a PS 2-3. With a median follow-up of 30.2 months, median OS was 7.2 months and median PFS 3.7 months. ORR was 39% and 24% of patients had disease stabilization. On univariate analysis, a PS of 2 or more was significantly associated with a worse OS (median OS 10.1 months if PS 0-1 versus 4.6 months if PS 2-3; HR = 1.68; 95%CI = 1.11-2.57; p = 0.01). Acute grade 3-4 hematologic and non-hematologic toxicity rates were 25.2% and 27.2%, respectively, with 11.8% of thrombopenia, 9.7% of neutropenia, 10% of skin toxicity, and 12.6% of asthenia. Patients with grade 1 or more skin toxicity had a higher ORR (HR = 3.44; 95%CI = 1.16-10.23; p = 0.03) and a prolonged OS (HR = 0.37; 95%CI = 0.23-0.58; p < 0.0001) and PFS (HR0.29; 95%CI = 0.19-0.47; p < 0.0001). During treatment, 29% of patients had a pain decrease, 13.5% a gain of weight, and 17.2% an improvement in PS. Conclusions: This is the largest cohort of patients treated with simplified EXTREME for HNSCC. Simplified EXTREME was well tolerated in this frail population with a high ORR. Patients with a good PS had prolonged survival. Interestingly, skin toxicity of any grade was significantly correlated with treatment efficacy.