Treatment Outcomes of Cetuximab-containing Regimen in Locoregional Recurrent and Distant Metastatic Head and Neck Squamous Cell Carcinoma

Background: Recurrent/ metastatic squamous cell carcinoma of head and neck (R/M SCCNH) is still a difficult-to-treat disease with poor clinical outcomes and limited treatment choices. In view of locoregional recurrent versus distant metastatic SCCHN, the therapeutic efficacy of cetuximab-containing regimen and relevant prognostic factors for these two groups may be different. Thus, the aim of this study was to explore the treatment outcomes of cetuximab-containing regimen in locoregional recurrent and distant metastatic SCCHN groups, and to identify clinical factors correlated with better survival outcomes.

Methods: From 2016 to 2020, patients with R/M SCCHN who received cetuximab-containing regimen in our institute were enrolled in this study. Clinical outcomes including overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and disease control rate (DCR) were evaluated in both locoregional recurrence and distant metastasis groups. Exploratory analysis were conducted to investigate major clinical features associated with better outcomes.

Results: A total of 107 patients with locoregional recurrent SCCHN (N = 66) and distant metastatic SCCNH (N = 41) who received cetuximab-containing regimen were enrolled in this retrospective study. Patients with oral cavity cancer and patients with disease recurrence within 6 months after radiation therapy were significantly increased in locoregional recurrence group. The median OS (15.6 vs. 9.7 months, P = 0.004) and PFS (5.8 months vs. 4.2 months, P = 0.008) were longer in locoregional recurrence group than in distant metastasis group. In multivariate analysis of clinical features, locoregional recurrence was still an important risk factor associated with better OS (Hazzard ratio (HR) 0.64, p = 0.06) and PFS (HR 0.67, p = 0.075). In addition, a trend of favorable disease control rate (DCR; 62.5% vs. 45.0%, p = 0.056) was noted in locoregional recurrence group. In locoregional recurrence group, prior salvage surgery was associated with longer OS (HR = 0.24, P = 0.008) and PFS (HR = 0.30, P = 0.005).

Conclusion: SCCHN with locoregional recurrence is associated with better disease control and survival outcomes comparing to distant metastatic SCCHN when treated with cetuximab-containing regimen. Salvage surgery for locoregional recurrence may further improves clinical outcome.