The Role of Immune Checkpoint Inhibitors in the Treatment of Less Common Head and Neck Cancers

Abstract

The role of immune checkpoint inhibitors in less common head and neck cancers, including non-squamous cell carcinoma, is less known. This chapter will focus on the currently available data about the use of immunotherapy for salivary gland carcinoma (SGC) and paranasal sinus carcinomas (PNC). Among SGCs, some high-grade non-adenoid cystic carcinomas (non-ACCs) may benefit from immunotherapy due to their immune-activated microenvironment. In contrast, ACCs have an immune-desert-like microenvironment and thus lack clinical benefit with immunotherapy. Theoretically, the association of immune checkpoint inhibitors with other targeted therapies (such as androgen deprivation therapy for androgen receptor-positive salivary duct carcinomas) might increase the clinical activity, but further studies are needed. Similar to the more prevalent HNSCC, PNCs are usually of squamous cell cancer histological type and may respond to immune checkpoint inhibitors. Sinonasal undifferentiated carcinoma (SNUC) may benefit from immunotherapy and clinical studies on induction chemotherapy for locally advanced disease should be designed. Intestinal-type adenocarcinoma (ITAC) has an immune-desert-like microenvironment and may lack clinical benefit from immunotherapeutic agents. For SGC and PNS, immunotherapy is not standard of care. Therefore, it should not be administered outside clinical trials.