It is estimated that over 47 million people use tobacco products, mostly in the form of combustible (smokable) tobacco cigarettes. Thirteen to 50% of smokers also use electronic cigarettes (also known as e-cigarettes or vaping). Use of tobacco is the primary preventable cause of death and risk factor for lung, head, neck, and oropharyngeal cancer. Electronic cigarettes are a $10 billion dollar industry and has the potential to surpass the tobacco cigarette market. E-cigarette use is a public health concern because of the health issues of vaping and the limited amount of scientific research to support the safety of e-cigarette use.
The authors of this paper want to create awareness that use of e-cigarettes is not a safer alternative to smoking tobacco cigarettes as e-cigarettes contain known carcinogens that may lead to development of oropharyngeal cancer.
Academic Editor: Sasho Stoleski, Ss. Cyril and Methodius University, Faculty of Medicine Skopje, Macedonia
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Copyright © 2022 Cameron Y. S. Lee, et al.
The authors have declared that no competing interests exist.
It is estimated that over 47 million people use tobacco products, mostly in the form of combustible (smokable) tobacco cigarettes.1Thirteen to 50% of smokers also use electronic cigarettes (also known as e-cigarettes or vaping).2,3Use of tobacco is the primary preventable cause of death and risk factor for lung, head, neck, and oropharyngeal cancer.4,5Cigarette smoke contains over seven hundred chemicals, including 60-70 known carcinogens. It is the combustible byproducts that lead to chronic tobacco-related disease and deaths after decades of smoking.6Compared to nonsmokers, the risk of developing lung cancer is twenty-five times greater. Cessation of smoking before age 40 decreases the risk of death by 90% from tobacco-related disease.7
Smoking is highest in adults aged 25- 64 years and it is estimated that 480,000 die annually from this social habit.8Oropharyngeal cancer is the sixth most common malignancy in the world.9The 5-year survival rate is approximately 75-83% due to high rates of recurrence with over 10,000 deaths per year in the United States.10,11The prevalence is highest in the following groups: people of color, individuals of low income and low education level, persons on Medicaid, disability benefits, uninsured and those with depression and anxiety.12
Electronic cigarettes are a $10 billion dollar industry and has the potential to surpass the tobacco cigarette market.13E-cigarette use is a public health concern because of the health issues of vaping and the limited amount of scientific research to support the safety of e-cigarette use.14
The authors of this paper want to create awareness that use of e-cigarettes is not a safer alternative to smoking tobacco cigarettes, as e-cigarettes contain known carcinogens that may lead to development of oropharyngeal cancer.
Increase in E-Cigarette Use
Although cigarette smoking has deceased in younger age groups, e-cigarette use has steadily increased, especially students in middle (4.7 %) and high school (19.6%).15In 2019, greater than 5.3 million middle and high school students used e-cigarettes. The increase in vaping is propelled by an increase in marketing, the perceived perception that vaping is safer compared to tobacco cigarettes, introduction of new vaping devices that include prefilled cartridges and pods and the many flavors that are appealing in taste. Of the over 15,000 vaping flavor blends, menthol is one of the most popular flavors that is commonly found in peppermint, spearmint and other mint plants and is considered safe. It is used in cough drops, candy, and gums because of its cooling sensation to the oral cavity. Compared to tobacco cigarettes, menthol is found in higher concentrations in e-cigarettes and increases the nicotine effects increasing the risk of nicotine addiction and could be why students get addicted to vaping.16
Health Risk of Nicotine
Nicotine is the major addictive compound in tobacco.17Each inhalation of cigarette smoke from a cigarette delivers to the brain 1 mg of nicotine within 7 to 30 seconds.18Most of the inhaled nicotine is metabolized into continine which is non-carcinogenic. However, inhaled nicotine is also metabolized into nitrosamines which are potent carcinogens and cause DNA damage. 17E-cigarettes contain higher amounts of nicotine compared to tobacco cigarettes and is the major component of e-cigarette smoke without having to burn tobacco. JUUL is the most common brand e-cigarette in the United States and each pod contains 5% (59mg/ml) nicotine.19
Nicotine is one of the main toxic substances in e-cigarettes and 45% released from vaping is deposited in the oral cavity.20Although there is no conclusive evidence that nicotine is involved in carcinogenesis in humans it has been shown that nicotine causes chromosomal abnormalities that results in DNA single strand breaks and mutations that could lead to cancer.21,22
Association of Carcinogens and Oropharyngeal Cancer
Studies have shown that oral mucosa and epithelial cells of the oropharynx are the first tissue exposed to tobacco smoke and e-liquid aerosols from vaping. Chemical analysis of the components of e-cigarette aerosols has revealed the presence of many harmful environmental toxins and carcinogens such as organic compounds (e.g., formaldehyde, acetaldehyde, benzaldehyde, acetone), free radicals and heavy metals (copper, chromium, iron, lead, arsenic, lead, nickel).23,24, 25In their study evaluating 225 e-liquid fluids, Lim and Shim 26discovered the presence of formaldehyde, acetaldehyde and nitrosamines that are carcinogenic to the head and neck region. In a New Egland Journal of Medicine study, Jensen and colleagues27also discovered formaldehyde in aerosols during the vaping process. Yu et. al.28 demonstrated that the vapors from e-cigarettes induced cell apoptosis resulting in cell death and DNA single strand breaks independent of the presence of nicotine. In another study by Flach and colleagues,29vaping liquid aerosols resulted in DNA double strand breaks that increases the risk of mutations and cancer. In a study on gene regulation and cell function of oral epithelial cells, Tommasi et. al.30 observed dysregulation of genes involved in carcinogenic pathways. Based on these studies, the use of e-cigarettes is a risk factor for oropharyngeal cancer.
There is a paucity of studies of oropharyngeal cancer from e-cigarette use due to the long duration of carcinogenesis and the recent introduction of e-cigarettes. The authors clearly believe that this is an urgent public health issue as there will be an exponential increase in the number of cases of oropharyngeal cancer due to the known carcinogenic components in e-cigarettes over the next few decades.
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