Chapter 19 - Aerodigestive Tract Chemoprevention Trials and Prevention of Second Primary Tumors

Abstract

This chapter focuses on the development of new treatment strategies and intermediate markers for head and neck cancer. The major cancer sites discussed include the oral cavity, pharynx, and larynx. Chemoprevention trials are based on the hypothesis that an interruption of the biological processes involved in carcinogenesis will inhibit this process and, in turn, reduce cancer incidence. This hypothesis provides a framework for the design and evaluation of chemoprevention trials, including the rationale for the selection of agents that are likely to inhibit biological processes and the development of intermediate markers associated with carcinogenesis. Various chemopreventive agents have been studied in over 40 randomized trials since 1990. Some clinical activity has been demonstrated in these studies, proving the potential utility of this method of cancer prevention. Still, large randomized trials are needed before chemoprevention agents can be fully integrated into standard oncologic practice. Chemopreventive agents have demonstrated efficacy thus far and may have a future role in treating and, more importantly, preventing head and neck cancers in high-risk individuals. Second primary tumors (SPTs) have emerged as an increasingly important problem, despite curative local therapy, underscoring the principle of field cancerization. Chemopreventive agents have impacted this arena as well and as further studies are performed, their role in preventing (SPTs) will be further defined. Small molecule compounds that target specific receptors or mutations may play a significant role as their side-effect profiles are tolerable.