The Role of Tumor Hypoxia in Head and Neck Cancer Radiotherapy

Abstract

Tumor hypoxia, or the condition of low tumor oxygenation, has been a focus of considerable debate in radiation therapy for almost 50 yr since the pioneering work of Gray and colleagues (1) demonstrating an oxygen dependency in the radiosensitivity of cells and tissues. During this period, interest among researchers has waxed and waned as promising new directions emerged from the laboratory, only to fail in clinical trials. However, with the emergence of new concepts and the development of new tools, the prospect of targeting tumor hypoxia and identifying patients who would most benefit from this approach appears more tangible clinically. This chapter discusses the significance of tumor hypoxia in head and neck squamous cell carcinomas (HNSCC) as well as past, present, and future strategies for targeting this microenvironmental factor.