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.