Smoking cessation and cancer

DEFINITION: Smoking cessation involves quitting the smoking of cigarettes, cigars, or pipes. Most smokers are physically addicted to nicotine and psychologically addicted to the habit.

The depth of the problem: According to the US Centers for Disease Control and Prevention (CDC), approximately 18 percent of adults in the United States (42.1 million people) were smokers in 2012. The use of tobacco products varies with gender, age, and ethnic background. The global prevalence of daily tobacco smoking in persons over the age of fifteen years is 31.1 percent for men and 6.2 percent for women.

Smoking is responsible for an estimated eight million global deaths per year and 480,000 in the United States. Smoking causes cancer, heart disease, stroke, and lung diseases such as emphysema and chronic bronchitis. Cancer was among the first diseases causally linked to smoking, and cigarette smoking is the leading preventable cause of death in the United States. Smoking is the leading risk factor for lung cancer and is responsible for about 90 percent of all lung cancer deaths. Smoking is estimated to increase the risk of coronary heart disease by two to four, stroke by two to four, and lung cancer by twenty-five times. Smoking causes damage to nearly every organ of the body. Quitting smoking can add years to a person's life.

Smoking cessation is a complex challenge involving overcoming physical and psychological dependence. Most smokers are addicted to nicotine—a psychoactive drug naturally found in tobacco products that produces dependence and makes quitting difficult. Additionally, smoking becomes a routine or habit that can be hard to break, especially when it is a coping mechanism for stress or anxiety. Cessation is difficult and often requires multiple attempts. Users commonly relapse because of withdrawal symptoms and mental dependence. Cigarette cravings are usually the worst during the first two to three days of smoking cessation. The physical symptoms of nicotine addiction last for about three weeks after quitting smoking, although the mental addiction to smoking typically lasts longer.

Quit and relapse rates: Approximately 70 percent of US adult smokers reported in 2011 that they would like to quit, according to the CDC. In 2011, an estimated 42.7 percent of adult smokers in the United States had attempted to quit smoking during the preceding twelve months.

However, not all smokers are successful in their attempts to stop smoking, and many try several times before they can quit. Less than 10 percent of smokers who attempt to quit on their own have long-term success. Most smokers cite symptoms of withdrawal and cravings as the main reasons for smoking relapse. Most relapses occur within three months of quitting. However, effective treatments can double or triple success rates.

Health benefits of cessation: Smoking cessation leads to nearly immediate health benefits for people with and without smoking-related diseases. People experience improved circulation almost immediately after quitting, decreased blood pressure and pulse rates, and increased body temperature in the hands and feet. Additionally, cessation leads to an almost immediate improvement in respiratory symptoms like coughing, wheezing, and shortness of breath. Carbon monoxide and nicotine levels in the body rapidly decrease.

The long-term health benefits of smoking cessation can be substantial. Smoking cessation dramatically reduces the risk of premature death by reducing the risk of smoking-related diseases. Former smokers live longer than those who continue to smoke. Former smokers who quit by age thirty can have their health become as good as a nonsmoker's. The risk of having a heart attack drops significantly within one year after quitting smoking and to about that of a nonsmoker after two to five years. Smoking cessation lowers the risk of developing and dying from lung cancer, other types of cancer, and other diseases—heart disease, stroke, chronic bronchitis, and emphysema. The risk of developing cancer declines with the number of years of smoking cessation. For example, ten years after quitting, a former smoker’s risk of dying from lung cancer is 50 percent less than for those who continue smoking. After five years of quitting, the risk of mouth, throat, esophagus, and bladder cancers decreases by half. Taste, smell, and lung function also improve.

Furthermore, smoking decreases fertility in both men and women. Women who stop smoking before or during pregnancy reduce their risk of having miscarriages and having babies with low birth weights. Smoking increases the risk of premature delivery, stillbirth, and sudden infant death syndrome (SIDS).

Although cessation is beneficial at all ages, the earlier a person stops smoking, the greater the health benefits.

Smoking cessation methods: Smoking cessation is a two-step process that includes overcoming the physical dependence on nicotine and breaking the smoking habit. Methods used to increase smoking cessation rates include medications, counseling, support groups, behavioral therapies, and alternative therapies such as hypnotism and acupuncture.

Effective medications for tobacco dependence include nicotine replacement therapies (NRTs) and non-nicotine treatments, such as bupropion and varenicline. NRTs provide users with small amounts of nicotine that help reduce the craving for cigarettes and relieve the withdrawal symptoms, making it easier to quit. Some are available without a doctor’s prescription. Although they contain some nicotine, NRTs are not as harmful as smoking because they do not contain the toxins and carcinogens found in tobacco products. Types of NRTs include gums, inhalers, nasal sprays, lozenges, and patches. Although these treatments are safe and effective when used as directed, smokers should talk with their healthcare providers before beginning any smoking cessation medication.

Nicotine gum (such as Nicorette), approved in 1984, was the first pharmacologic smoking cessation aid approved by the US Food and Drug Association (FDA). The recommended treatment is typically at least nine pieces of gum daily for the first six weeks, followed by a gradual reduction.

Available only by prescription, the nicotine inhaler (Nicotrol) is a plastic cylinder that looks like a cigarette and has a cartridge that delivers nicotine. After using nicotine inhalation for twelve weeks, your doctor may begin to decrease your dose gradually. Side effects of nicotine inhalation include mouth and throat irritation.

Nicotine nasal sprays are dispensed from pumps. The nicotine is rapidly absorbed through the nasal membranes and quickly reaches the bloodstream. A usual dose is one to two sprays following a craving to smoke. Side effects include nose and throat irritation.

Nicotine patches (such as Nicoderm) release a constant amount of nicotine throughout the day. Most patches are replaced daily for six to ten weeks. They come in different shapes and sizes. Side effects of nicotine patches include skin irritation, dizziness, headache, nausea, and vomiting. Some studies suggest the patch is less effective than inhalers or gum because the continuous release of nicotine does not allow the individual to overcome periodic cravings.

The first and only over-the-counter nicotine lozenge was introduced to the market in 2002. It is a hard candy that slowly releases nicotine as it dissolves in the mouth. The most common side effects are sore teeth and gums, indigestion, and throat irritation.

Available only by prescription, bupropion was approved by the FDA as a smoking cessation aid in 1997. Unlike with NRTs, treatment with bupropion begins while the user is still smoking, typically one week before the quit date, and continues for seven to twelve weeks. The length of treatment is individualized. Common side effects include insomnia, dry mouth, and dizziness.

The prescription drug varenicline was approved in 2006 for smoking cessation. Typically, this nicotine-free tablet is taken twice daily for twelve weeks. Common side effects include headache, nausea and vomiting, gas, insomnia, and change in taste perception. Possible serious adverse effects include changes in behavior, agitation, depressed mood, and suicide ideation. Individuals should discontinue varenicline and immediately contact their doctor if such serious psychiatric adverse effects occur.

Doctors should provide routine smoking cessation interventions to patients who smoke, offering advice and support on how to quit. A combination of counseling and medication is more effective than either alone, and clinicians should offer both to aid in smoking cessation. Phone counseling (including quitlines), group counseling, and individual counseling improve smoking cessation rates.

Symptoms of smoking withdrawal: Smokers who try to quit may face physical and psychological symptoms of withdrawal. Physically, the body reacts to the absence of nicotine. Symptoms of withdrawal include dizziness, depression, irritability, anxiety, sleep disturbances, headaches, difficulty concentrating, drowsiness, and increased appetite. They typically start within a few hours of the last cigarette and peak about two to three days later. Mentally, the smoker must break the habit of coping with stress by smoking.

Bibliography

Benowitz, Neal L., et al. "How the FDA can Improve Public Health—Helping People Stop Smoking." New England Journal of Medicine, vol. 388, no. 17, 2023, pp. 1540-1542. doi:10.1056/NEJMp2301700.

Casey, Karen. Stop Smoking and Vaping Now! : How to Recover from Nicotine Addiction. Mango Publishing, 2024.

"Health Risks of Smokeless Tobacco." American Cancer Society, 28 Oct. 2020, www.cancer.org/cancer/risk-prevention/tobacco/health-risks-of-tobacco/smokeless-tobacco.html. Accessed 20 July 2024.

Hecht, Stephen S., and Dorothy K. Hatsukami. "Smokeless Tobacco and Cigarette Smoking: Chemical Mechanisms and Cancer Prevention." Nature Reviews Cancer, vol. 22, no. 3, 2022, pp. 143-155. doi.org/10.1038/s41568-021-00423-4.

Hecht, Stephen S., and Dorothy K. Hatsukami. Tobacco and Cancer. World Scientific Publishing Company, 2022. 

Koskinen, Charles J., ed. Handbook of Smoking and Health. Nova, 2011.

LaTorre, Giuseppe. Smoking Prevention and Cessation. Springer, 2013.

Murray, Rachael L., and Emma O’Dowd. "Smoking Cessation and Lung Cancer: Never Too Late to Quit." The Lancet Public Health, vol. 8, no. 9, 2023. doi.org/10.1016/S2468-2667(23)00158-5.