Chemoprevention – prophylaxis and adjuvant therapy of head and neck cancers

After a quarter of a century of rapid advances in cancer research, the focus of oncological drug development has shifted from cytotoxic chemotherapy to rationally designed agents that target specific molecules associated with malignant cells or their environment. Carcinogenic process is driven by mutation, but there are many epigenetic variables which could be the targets of early intervention before invasion and metastasis occur. Chemoprevention is the inhibition, retardation or reversal of carcinogenic processes by pharmacological or natural agents targeting these pathways in high-risk individuals. This approach was developed more than 30 years ago and its credibility was enhanced by the positive results of clinical trials involving subjects with the risk of head and neck second primary tumors. So far however not many clinical trials provided satisfying results not only because of the lack of efficacy or side toxic effects of chemopreventive agents but also the lack of precise biomarkers monitoring their effects. Despite the problems which have to be solved before their application chemopreventive agents are considered as the drugs of 21. century.
This article reviews the conceptual basis of chemoprevention and perspectives of its application in head and neck cancers.