Cigarette Smoking and Cancer: Questions and Answers
|Key Points -Cigarette smoking causes 87 percent of lung cancer deaths and is responsible for most cancers of the larynx, oral cavity and pharynx, esophagus, and bladder .-Secondhand smoke is responsible for an estimated 3,000 lung cancer deaths among U.S. nonsmokers each year .-Tobacco smoke contains thousands of chemical agents, including over 60 substances that are known to cause cancer .-The risk of developing smoking-related cancers, as well as noncancerous diseases, increases with total lifetime exposure to cigarette smoke .-Smoking cessation has major and immediate health benefits, including decreasing the risk of lung and other cancers, heart attack, stroke, and chronic lung disease .|
Tobacco use, particularly cigarette smoking, is the single most preventable cause of death in the United States. Cigarette smoking alone is directly responsible for approximately 30 percent of all cancer deaths annually in the United States (1). Cigarette smoking also causes chronic lung disease (emphysema and chronic bronchitis), cardiovascular disease, stroke, and cataracts. Smoking during pregnancy can cause stillbirth, low birthweight, Sudden Infant Death Syndrome (SIDS), and other serious pregnancy complications . Quitting smoking greatly reduces a person’s risk of developing the diseases mentioned, and can limit adverse health effects on the developing child.
What are the effects of cigarette smoking on cancer rates? Cigarette smoking causes 87 percent of lung cancer deaths . Lung cancer is the leading cause of cancer death in both men and women. Smoking is also responsible for most cancers of the larynx, oral cavity and pharynx, esophagus, and bladder. In addition, it is a cause of kidney, pancreatic, cervical, and stomach cancers, as well as acute myeloid leukemia.
Are there any health risks for nonsmokers? The health risks caused by cigarette smoking are not limited to smokers. Exposure to secondhand smoke, or environmental tobacco smoke (ETS), significantly increases the risk of lung cancer and heart disease in nonsmokers, as well as several respiratory illnesses in young children. (Secondhand smoke is a combination of the smoke that is released from the end of a burning cigarette and the smoke exhaled from the lungs of smokers.) The U.S. Environmental Protection Agency (EPA), the National Institute of Environmental Health Science’s National Toxicology Program, and the World Health Organization’s International Agency for Research on Cancer (IARC) have all classified secondhand smoke as a known human carcinogen—a category reserved for agents for which there is sufficient scientific evidence that they cause cancer. The U.S. EPA has estimated that exposure to secondhand smoke causes about 3,000 lung cancer deaths among nonsmokers and is responsible for up to 300,000 cases of lower respiratory tract infections in children up to 18 months of age in the United States each year. For additional information on ETS, see the NCI fact sheet Environmental Tobacco Smoke, which can be found at http://www.cancer.gov/cancertopics/factsheet/Tobacco/ETS on the Internet.
What harmful chemicals are found in cigarette smoke? Cigarette smoke contains about 4,000 chemical agents, including over 60 carcinogens. In addition, many of these substances, such as carbon monoxide, tar, arsenic, and lead, are poisonous and toxic to the human body. Nicotine is a drug that is naturally present in the tobacco plant and is primarily responsible for a person’s addiction to tobacco products, including cigarettes. During smoking, nicotine is absorbed quickly into the bloodstream and travels to the brain in a matter of seconds. Nicotine causes addiction to cigarettes and other tobacco products that is similar to the addiction produced by using heroin and cocaine.
How does exposure to tobacco smoke affect the cigarette smoker? Smoking harms nearly every major organ of the body. The risk of developing smoking-related diseases, such as lung and other cancers, heart disease, stroke, and respiratory illnesses, increases with total lifetime exposure to cigarette smoke. This includes the number of cigarettes a person smokes each day, the intensity of smoking (i.e., the size and frequency of puffs), the age at which smoking began, the number of years a person has smoked, and a smoker’s secondhand smoke exposure.
How would quitting smoking affect the risk of developing cancer and other diseases? Smoking cessation has major and immediate health benefits for men and women of all ages. Quitting smoking decreases the risk of lung and other cancers, heart attack, stroke, and chronic lung disease. The earlier a person quits, the greater the health benefit. For example, research has shown that people who quit before age 50 reduce their risk of dying in the next 15 years by half compared with those who continue to smoke. Smoking low-yield cigarettes, as compared to cigarettes with higher tar and nicotine, provides no clear benefit to health. For additional information on quitting smoking, see the NCI fact sheet Questions and Answers About Smoking Cessation, which can be found at http://www.cancer.gov/cancertopics/factsheet/Tobacco/cessation on the Internet.For additional information about cancer or tobacco use, visit the NCI’s Web site about tobacco at http://www.cancer.gov/cancerinfo/tobacco on the Internet. For help with quitting smoking, visit NCI’s smoking cessation Web site at http://www.smokefree.gov on the Internet.
Smoking and Cancer – Statistics for the U.S.
When people think of cancers caused by smoking, the first one that comes to mind is always lung cancer. Most cases of lung cancer death, close to 90% in men, and 80% in women are caused by cigarette smoking. There are several other forms of cancer attributed to smoking as well, and they include cancer of the oral cavity, pharynx, larynx, esophagus, bladder, stomach, cervix, kidney and pancreas, and acute myeloid leukemia. The list of additives allowed in the manufacture of cigarettes consists of 599 possible ingredients. When burned, cigarette smoke contains over 4000 chemicals, with over 40 of them being known carcinogens. Cancer is the second leading cause of death and was among the first diseases causally linked to smoking. Lung cancer is the leading cause of cancer death, and cigarette smoking causes most cases. Compared to nonsmokers, men who smoke are about 23 times more likely to develop lung cancer and women who smoke are about 13 times more likely. Smoking causes about 90% of lung cancer deaths in men and almost 80% in women. In 2003, an estimated 171,900 new cases of lung cancer occurred and approximately 157,200 people died from lung cancer. The 2004 Surgeon General’s report adds more evidence to previous conclusions that smoking causes cancers of the oral cavity, pharynx, larynx, esophagus, lung and bladder. Cancer-causing agents (carcinogens) in tobacco smoke damage important genes that control the growth of cells, causing them to grow abnormally or to reproduce too rapidly. Cigarette smoking is a major cause of esophageal cancer in the United States. Reductions in smoking and smokeless tobacco use could prevent many of the approximately 12,300 new cases and 12,100 deaths from esophgeal cancer that occur annually. The combination of smoking and alcohol consumption causes most laryngeal cancer cases. In 2003, an estimated 3800 deaths occurred from laryngeal cancer. In 2003, an estimated 57,400 new cases of bladder cancer were diagnosed and an estimated 12,500 died from the disease. For smoking-attributable cancers, the risk generally increases with the number of cigarettes smoked and the number of years of smoking, and generally decreases after quitting completely. Smoking cigarettes that have a lower yield of tar does not substantially reduce the risk for lung cancer. Cigarette smoking increases the risk of developing mouth cancers. This risk also increases among people who smoke pipes and cigars. Reductions in the number of people who smoke cigarettes, pipes, cigars, and other tobacco products or use smokeless tobacco could prevent most of the estimated 30,200 new cases and 7,800 deaths from oral cavity and pharynx cancers annually in the United States. New cancers confirmed by this report: The 2004 Surgeon General’s report newly identifies other cancers caused by smoking, including cancers of the stomach, cervix, kidney, and pancreas and acute myeloid leukemia. In 2003, an estimated 22,400 new cases of stomach cancer were diagnosed, and an estimated 12,100 deaths were expected to occur. Former smokers have lower rates of stomach cancer than those who continue to smoke. For women, the risk of cervical cancer increases with the duration of smoking. In 2003, an estimated 31,900 new cases of kidney cancer were diagnosed, and an estimated 11,900 people died from the disease. In 2003, an estimated 30,700 new cases of pancreatic cancer were diagnosed, attributing to 30,000 deaths. The median time from diagnosis to death from pancreatic cancer is about 3 months. In 2003, approximately 10,500 cases of acute myeloid leukemia were diagnosed in adults.
Benzene is a known cause of acute myleoid leukemia, and cigarette smoke is a major source of benzene exposure. Among U.S. smokers, 90% of benzene exposures come from cigarettes.
The List of Additives A through CThe list of 599 additives approved by the US Government for use in the manufacture of cigarettes is something every smoker should see. Submitted by the five major American cigarette companies to the Dept. of Health and Human Services in April of 1994, this list of ingredients had long been kept a secret.Tobacco companies reporting this information were:
American Tobacco Company
Brown and Williamson
Liggett Group, Inc.
Philip Morris Inc.
R.J. Reynolds Tobacco Company
While these ingredients are approved as additives for foods, they were not tested by burning them, and it is the burning of many of these substances which changes their properties, often for the worse. Over 4000 chemical compounds are created by burning a cigarette, many of which are toxic and/or carcinogenic. Carbon monoxide, nitrogen oxides, hydrogen cyanide and ammonia are all present in cigarette smoke. Forty-three known carcinogens are in mainstream smoke, sidestream smoke, or both.It’s chilling to think about not only how smokers poison themselves, but what others are exposed to by breathing in the secondhand smoke. The next time you’re missing your old buddy, the cigarette, take a good long look at this list and see them for what they are: a delivery system for toxic chemicals and carcinogens.Cigarettes offer people only a multitude of smoking-related diseases and ultimately death.
This is THE LIST!