Head and neck cancer is the sixth most common form of cancer worldwide. In 2016, it is estimated that 61,760 patients were diagnosed with head and neck cancer in the United States. Worldwide, 550,000 people are diagnosed with, and about 380,000 people die from, head and neck cancer each year. Tobacco products are implicated in the generation of multiple cancer types including lung, esophageal, bladder, and pancreatic cancer as well as many cardiovascular and respiratory diseases [ Tobacco use is also strongly associated with head and neck squamous cell carcinoma (HNSCC). Specifically, this includes tumors of the oral cavity, nasopharynx, oropharynx, hypopharynx, and larynx. The last several years have witnessed steadily increasing understanding of the carcinogenic constituents contained in tobacco products as well as their roles in generating specific tumors.
Over the long history of tobacco production, many different forms have been developed. These include both combustible and smokeless products. Combustible tobacco products include cigarettes, cigars, bidis, chutta, and kretek. Tobacco products can also be smoked using pipes or a variety of water pipes.
Cigarette - Any roll of tobacco wrapped in paper or other non-tobacco material; filter-tipped or untipped; approximately 8 mm in diameter, 70–120 mm in length.
Any roll of tobacco wrapped in leaf tobacco or in any other substance containing tobacco.
Cigar - Types: little cigars, small cigars (‘cigarillos’), regular cigars, premium cigars.
Some little cigars are filter tipped and are shaped like cigarettes.
Regular cigars are up to 17 mm in diameter, 110–150 mm in length.
Bidi - Hand-rolled Indian cigarette; sun-dried temburni leaf rolled into a conical shape together with flaked tobacco and secured with a thread.
Chutta - Hand-rolled cigarette used for reverse smoking primarily by women in India.
Kretek - Small cigar containing tobacco (approximately 60%), cloves and cocoa. The burning blend gives a characteristic flavor and ‘honey’ taste to the smoke.
In India, the use of smokeless tobacco products is associated with many social activities. In addition, misconceptions are very common in regards to these products. For example, many smokeless products are thought to be useful as mouth fresheners and, as a result, are applied to the gingiva and teeth regularly which results in an increased risk for oral cancer. A well-known example of this phenomenon is gutkha, an Indian product that was previously espoused as a mouth freshener and is now banned in many Indian states. Still, additional smokeless products are widely available in India and are inexpensive. These two factors create a situation where everyday use by average citizens becomes widespread [20]. The cost may be so low that even school children can afford them [20]. In addition, marketing strategies aim to make these products more palatable and attractive. For example, the use of colorful packaging and various scents, sweeteners, and spices are used to attract buyers [20]. The use of appealing product names or names with religious significance, is also used to appeal to different social groups [20]. Due to the widespread use of smokeless tobacco products, 74% of the global burden of HNSCC occurs in India [21]. Indians develop HNSCC (oral cavity, lip, pharynx) at the highest rate in the world at 20 cases per 100,000 people.
Since the Surgeon General’s report in 1964, there has been tremendous effort to study the carcinogenic effects of tobacco products. These research efforts have led to significant advances in understanding the constituents of tobacco products. To date, over 70 known carcinogens have been described in cigarette
In addition to the carcinogenic effects of tobacco, numerous studies have demonstrated negative effects on a variety of treatment-related outcomes among smokers with HNSCC. These include radiation efficacy, surgical outcomes, and wound complications.
In addition to impacting disease outcomes, tobacco use can also affect wound healing and more acute surgical outcomes. Hatcher et al investigated the risk of tobacco use on post-operative surgical outcomes. On the day of surgery, recent tobacco use was assessed by urinary cotinine. Patients undergoing surgical treatment for HNSCC who were current or former smokers were 6 times more likely to have a complication (vascular, pulmonary, renal, acute blood loss anaemia, ethanol withdrawal, wound complications, and other complications such as urinary tract infection or delirium) and a longer length of stay than never smokers.
Smoking has been demonstrated to impair wound healing and end organ oxygen delivery [49]. Researchers believe that smoking impairs endothelial migration at surgical anastomosis and can lead to luminal thrombosis after free tissue transfer. Nicotine also has direct vasoconstrictive effects on the microvascular circulation. Eighty-nine patients undergoing 101 free flap reconstructions were enrolled in a prospective epidemiologic study of HNSCC (oral cavity, oropharynx, larynx, hypopharynx).
Worldwide, head and neck cancer is a significant problem. Tobacco products, both smokeless and combustible, play a large role in the development of HNSCC in addition to leading to poorer treatment outcomes.
Head and neck cancer (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, 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 10 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.
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