Real world efficacy of cetuximab plus chemotherapy as first-line treatment of recurrent and/or metastatic head and neck squamous cell carcinoma.

Abstract

e18032 Background: Head and neck squamous cell carcinoma (HNSCC) represent a major therapeutic challenge due to its biological heterogeneity and variable prognosis. The use of cetuximab combinations plus chemotherapy has been shown to improve survival outcomes. This study aimed to evaluate the clinical characteristics and the impact of cetuximab-based therapy on overall survival (OS) and progression-free survival (PFS) in patients with recurrent and/or metastatic (R/M) HNSCC. Methods: A retrospective study was conducted including patients diagnosed with R/M HNSCC and treated at the Instituto Nacional de Enfermedades Neoplásicas (INEN) between 2020 and 2024. Clinical variables, response rates, OS, and PFS were analyzed. Survival outcomes were estimated using Kaplan–Meier curves. For survival analysis, patients should receive at least three cycles of cetuximab in combination with chemotherapy. Results: Fifty patients were included, with a median age of 56 years (34% aged >60 years), 54% male, 39% with primary tumors in the oral cavity, and 32% in the oropharynx (19.6% IHC p16-positive). Moderately differentiated carcinoma was the most frequent histology (83.3%). Most patients (80%) had ECOG performance status 1; 34% had a BMI <18, and 78% presented a prognostic nutritional index (PNI) >45. At the start of cetuximab therapy, 38% had systemic disease (14% with concomitant locoregional recurrence), with the lung being the most common metastatic site (94.7%). 80% of patients had received prior treatment: 32.5% radiotherapy alone, 22.5% surgery plus adjuvant radiotherapy, 17.5% surgery plus adjuvant chemoradiotherapy, 17.5% induction chemotherapy followed by radiotherapy alone, 5% induction chemotherapy followed by concurrent chemoradiotherapy, and 5% definitive concurrent chemoradiotherapy. For R/M disease, the most common regimen was cetuximab plus carboplatin and taxanes (60%), followed by the TEPEx regimen (22%). 74% of patients received at least three cycles of chemotherapy. The objective response rate (ORR) was 32.4% (CR = 5.4%, PR = 27%), and the clinical benefit rate (CR + PR + SD) was 70.2%. Maintenance therapy was administered to 51.4% of patients. The median PFS was 6.87 months (5.99-7.74), median OS since initiation of cetuximab was 9.87 months (5.62-14.12), and median OS since initial diagnosis was 22.1 months (19.17-25.03). Conclusions: Cetuximab-based chemotherapy provided meaningful clinical benefit in patients with recurrent and/or metastatic HNSCC, with survival outcomes comparable to those reported in real-world settings. These findings support the continued use of cetuximab in combination regimens as an effective therapeutic option.