Head and Neck Squamous Cell Carcinoma (HNSCC) is a cancer that originates in the mucosal surfaces of the head and neck, including the mouth, throat, and larynx. Immunotherapy has emerged as a promising treatment for HNSCC, especially for patients whose cancers are resistant to traditional therapies such as surgery, radiation, and chemotherapy. In this minireview article, we summarized the role of immunotherapy in HNSCC. Checkpoint inhibitors are a class of immunotherapy that work by blocking certain proteins that suppress the immune system’s ability to attack cancer cells. In HNSCC, the most studied checkpoint inhibitors are PD-1/PD-L1 Inhibitors. These include drugs like Pembrolizumab (Keytruda) and Nivolumab (Opdivo). PD-1 is a protein on immune cells that, when engaged by its ligands (PD-L1 on cancer cells), dampens the immune response. Blocking PD-1 helps reactivate the immune system to recognize and destroy cancer cells. Drugs like Atezolizumab (Tecentriq) target the PD-L1 protein, which is often upregulated in cancer cells to escape immune surveillance. By blocking PD-L1, these drugs prevent cancer cells from evading the immune system. These checkpoint inhibitors have shown efficacy in advanced or recurrent HNSCC, particularly in patients whose tumors express PD-L1. Combination strategies that combine immunotherapy with other treatments, such as chemotherapy, radiation therapy, or targeted therapy, are also being explored to enhance the effectiveness of immunotherapy in HNSCC. These combinations can help overcome resistance mechanisms and potentially improve outcomes. Chemotherapy may induce immune-stimulatory effects, making the tumor more sensitive to immunotherapy. Radiation can induce "immunogenic cell death," releasing tumor antigens that can enhance the immune system’s response to the cancer when combined with checkpoint inhibitors. While immunotherapy has shown promising results in treating HNSCC, several challenges remain. For example, not all tumors respond equally to immunotherapy, and some cancers develop resistance over time. Tumors can create a microenvironment that suppresses immune activity, making it difficult for immunotherapies to work effectively. Immune-related side effects, such as inflammation or autoimmunity, can occur with checkpoint inhibitors. Research continues into refining biomarkers for patient selection, optimizing combination therapies, and finding ways to overcome resistance. In conclusion, immunotherapy represents a major advancement in the treatment of HNSCC, offering new hope for patients with advanced or recurrent disease. Ongoing research is focusing on improving the efficacy, safety, and applicability of these therapies, with the goal of enhancing patient outcomes and expanding their use across different subtypes of HNSCC.
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