Pathologic Response to Neoadjuvant Cetuximab, Platinum, and Taxane in Locally Advanced HNSCC

OBJECTIVE: Taxane, platinum, and cetuximab (TPC) is effective as neoadjuvant therapy for advanced head and neck squamous cell carcinoma (HNSCC) and induces pathologic responses that influences clinical outcomes. STUDY DESIGN: Retrospective cohort study conducted from 1990 to 2023. SETTING: Memorial Sloan Kettering Cancer Center. METHODS: Patients with HNSCC who received TPC/TPF before definitive therapy were retrospectively reviewed. Patients were assessed for radiographic and pathologic response, disease-free survival (DFS), and overall survival (OS). Radiographic response was defined as any tumor shrinkage assessed by a radiologist. Pathologic response on the primary (tumor) and lymph nodes was categorized as complete (pCR), near complete (pNCR), partial (pPR), and no response (pNR), corresponding to treatment effects of 100%, 90%-99%, 11%-89%, and <10%, respectively. Pathologic objective response rate (pORR) = pCR + pNCR + pPR. RESULTS: Fifty-six patients received TPC; pORR was 71% for the primary tumor and 61% overall (primary + lymph nodes), while the pCR + pNCR rate for primary tumors was 29% and 20% for overall. Radiographic response before definitive surgical treatment was 88%. pORR in the primary tumor was associated with improved DFS (P = .001) and OS (P = .040). Overall pORR showed improved DFS (P = .024) and trend towards improved OS compared to pNR (P = .145). CONCLUSION: TPC appears to be effective for HNSCC before surgery, and pathologic responses may inform clinical outcomes. Pathologic response criteria defined in this study can establish a standardized and uniform approach for assessment after neoadjuvant treatment for HNSCC.