The efficacy and safety of the addition of programmed cell death protein 1 inhibitor to preoperative chemotherapy in locoregionally advanced oropharyngeal carcinoma.

Background: Immune checkpoint inhibitors have shown promise in improving the survival rates for recurrent and/or metastatic head and neck cancers. However, their impact on curative outcomes in head and neck cancers remains undefined, especially for those with locoregionally advanced oropharyngeal carcinoma (LAOPC), a subtype of head-and-neck malignancy closely associated with human papillomavirus infection. This study aimed to clarify the efficacy and safety of the addition of programmed cell death protein 1 (PD-1) inhibitor into preoperative chemotherapy in LAOPC. Methods: We retrospectively included patients with LAOPC who underwent preoperative immunochemotherapy between 2021 and 2024. Statistical analyses were conducted using chi-square tests. The efficacy was assessed using Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1). Safety was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE) 5.0. Results: A total of 23 patients were identified, and 11 (47.8%) had P16-positive tumors. There were 22 patients (95.7%) who completed two cycles of preoperative treatment. Among the 23 patients, the response to primary tumors and neck metastatic lymph nodes could be assessed in 21 and 22 patients, respectively. Additionally, 13 (61.9%) patients had a major pathologic response to the primary tumor, including 12 patients (57.1%) who achieved a pathologic complete response (PCR). In addition, 11 (50.0%) patients had a PCR in the metastatic cervical lymph nodes, while 11 (50.0%) patients still had residual tumors in the lymph nodes. The combined positive score and P16 status were not significantly associated with PCR to the primary tumor or neck metastatic lymph nodes. Moreover, 19 (82.6%) patients experienced treatment-related adverse effects, with the majority being grade 1-2 toxicities, and only 2 (8.7%) patients had grade 3 or higher toxicities. No treatment-related deaths occurred. Conclusions: The incorporation of a PD-1 inhibitor into preoperative chemotherapy may be an effective approach for treating LAOPC and involve acceptable toxicity.