Tobacco-related carcinogenesis in head and neck cancer.

Head and neck cancer (head and neck squamous cell carcinoma (HNSCC)) is a devastating disease. Patients require intensive treatment that is often disfiguring and debilitating. Those who survive are often left with poor speech articulation, difficulties in chewing and swallowing, and cosmetic disfigurement, as well as loss of taste. Furthermore, given that HNSCC survivors are frequently disabled and unable to return to work, the economic and societal costs associated with HNSCC are massive. HNSCC is one of many cancers that are strongly associated with tobacco use. The risk for HNSCC in smokers is approximately ten times higher than that of never smokers, and 70-80% of new HNSCC diagnoses are associated with tobacco and alcohol use. Tobacco products have been used for centuries; however, it is just within the last 60-70 years that we have developed an understanding of their damaging effects. This relatively recent understanding has created a pathway towards educational and regulatory efforts aimed at reducing tobacco use. Understanding the carcinogenic components of tobacco products and how they lead to HNSCC is critical to regulatory and harm reduction measures. To date, nitrosamines and other carcinogenic agents present in tobacco products have been associated with cancer development. The disruption of DNA structure through DNA adduct formation is felt to be a common mutagenic pathway of many carcinogens. Intense work pertaining to tobacco product constituents, tobacco use, and tobacco regulation has resulted in decreased use in some parts of the world. Still, much work remains as tobacco continues to impart significant harm and contribute to HNSCC development worldwide.