Immunotherapy for Head and Neck Squamous Cell Carcinoma

Abstract

Purpose of review: Discussion of current strategies targeting the immune system related to solid tumors with emphasis on head and neck squamous cell carcinoma (HNSCC).This review will outline the current challenges with immunotherapy and future goals for treatment using these agents.

Recent findings: Agents targeting immune checkpoint receptors (IR) such as program death 1 (PD1) have been used in the clinical realm for melanoma and non-small cell lung cancer (NSCLC), and the use of these agents for these malignancies has provided crucial information about how and why patients respond or not to inhibitory checkpoint receptor blockade therapy (ICR). The anti PD1 agent, nivolumab, was recently approved by the FDA as a standard of care regimen for patients with platinum refractory recurrent/metastatic (R/M) HNSCC. Molecular pathways leading to resistance are starting to be identified, and work is underway to understand the most optimal treatment regimen with incorporation of immunotherapy. ICR has renewed interest in the immunology of cancer, but resistance is not uncommon, and thus understanding of these mechanisms will allow the clinician to appropriately select patients that will benefit from this therapy.

Keywords: CTLA4; Checkpoint receptor; Immune checkpoint receptor blockade; Immuno-oncology; PD1; Tumor infiltrating lymphocyte.

Fig. 1

Mechanisms of immune escape. Processed tumor antigen is presented to T cells by antigen presenting cells such as dendritic cells. T cells and natural killer cells (NK) targeting tumor cells are thwarted by tumor “immunoediting” via downregulation of antigen processing machinery (APM). Intrinsic suppressive signals on tumor antigen specific T cells (checkpoint receptors such as PD1) as well as extrinsic suppressive signals from regulatory T cells (Treg) contribute to tumor immune escape