13.4: Cancer Risk and Prevention
Cancer prevention are actions you can take to lower the chance of getting cancer. It is usually not possible to know exactly why one person develops cancer and another doesn’t. But research has shown that certain risk factors may increase a person’s chances of developing cancer. Understanding the risk factors can help you to make lifestyle choices to try to prevent or lower your risk of cancer.
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Age
- Advancing age is the most important risk factor for cancer overall and for many individual cancer types. The incidence rates for cancer overall climb steadily as age increases, from fewer than 25 cases per 100,000 people in age groups under age 20, to about 350 per 100,000 people among those aged 45–49, to more than 1,000 per 100,000 people in age groups 60 years and older.
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Alcohol
- Drinking alcohol can increase your risk of cancer of the mouth, throat, esophagus, larynx (voice box), liver, and breast. The more you drink, the higher your risk. The risk of cancer is much higher for those who drink alcohol and also use tobacco.
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Environmental Carcinogens
- People can avoid some cancer-causing exposures, such as tobacco smoke and the sun’s rays. But other ones are harder to avoid, especially if they are in the air we breathe, the water we drink, the food we eat, or the materials we use to do our jobs. Being exposed to chemicals and other substances in the environment has been linked to some cancers. A few carcinogens in our environment include: Arsenic, formaldehyde, asbestos, radon, wood dust, mineral oils, and soot.
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Chronic Inflammation
- In chronic inflammation, the inflammatory process may begin even if there is no injury, and it does not end when it should. Why the inflammation continues is not always known. Chronic inflammation may be caused by infections that don’t go away, abnormal immune reactions to normal tissues, or conditions such as obesity. Over time, chronic inflammation can cause DNA damage and lead to cancer.
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Diet
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Many studies have looked at the possibility that specific dietary components or nutrients are associated with increases or decreases in cancer risk, however results have been inconclusive or need further research. It is hard to study the effects of diet on cancer because a person’s diet includes foods that may protect against cancer and foods that may increase the risk of cancer. Although the research is inconclusive, dietary relations to cancer have included:
- Antioxidants may lower cancer risk by blocking the activity of free radicals that damage cells.
- Artificial sweeteners have been shown to cause bladder cancer in animals.
- Higher intakes of calcium and may reduce risks of colorectal cancer.
- Charred meat increases exposure to chemicals that can cause cancer in animals.
- Red meat is associated with an increased risk of colon and rectum cancer.
- Cruciferous vegetables may have anticancer effects.
- Fluoridated water helps decrease tooth decay, but may increase cancer risk.
- Tea may lower cancer risk by blocking the activity of free radicals that damage cells.
- Higher intakes of vitamin D or higher levels of vitamin D in the blood may be associated with a reduced risk of colorectal cancer.
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Many studies have looked at the possibility that specific dietary components or nutrients are associated with increases or decreases in cancer risk, however results have been inconclusive or need further research. It is hard to study the effects of diet on cancer because a person’s diet includes foods that may protect against cancer and foods that may increase the risk of cancer. Although the research is inconclusive, dietary relations to cancer have included:
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Hormones
- Estrogens, a group of female sex hormones, are known human carcinogens. Although these hormones have essential physiological roles in both females and males, they have also been associated with an increased risk of certain cancers.
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Immunosuppression
- Many people who receive organ transplants take medications to suppress the immune system so the body won’t reject the organ. These “immunosuppressive” drugs make the immune system less able to detect and destroy cancer cells or fight off infections that cause cancer.
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Infectious Agents
- Certain infectious agents, including viruses, bacteria, and parasites, can cause cancer or increase the risk that cancer will form.
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Obesity
- People with obesity may have an increased risk of several types of cancer, including cancers of the breast (in women who have been through menopause), colon, rectum, endometrium (lining of the uterus), esophagus, kidney, pancreas, and gallbladder.
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Radiation
- Radiation of certain wavelengths, called ionizing radiation, has enough energy to damage DNA and cause cancer.
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Sunlight
- The sun, sunlamps, and tanning booths all give off ultraviolet (UV) radiation. Exposure to UV radiation causes early aging of the skin and damage that can lead to skin cancer.
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Tobacco
- Tobacco use is a leading cause of cancer and of death from cancer. Cigarette smoking is the number one risk factor for lung cancer. In the United States, cigarette smoking is linked to about 80% to 90% of lung cancer deaths. People who smoke cigarettes are 15 to 30 times more likely to get lung cancer or die from lung cancer than people who do not smoke.
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Physical activity
- Studies show that people who are physically active have a lower risk of certain cancers than those who are not. It is not known if physical activity itself is the reason for this.
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Diabetes
- Some studies show that having diabetes may slightly increase the risk of having several different types of cancer.