Although there are many different types of cancer, which have different causes and risk factors Risk Factors for Cancer Many genetic and environmental factors increase the risk of developing cancer. However, not all people who are exposed to carcinogens or who have other risk factors develop cancer. (See also... read more , doctors estimate that about 40% of cancers are preventable. Also, individual people have different risks for developing different cancers. Therefore, no set of prevention strategies is effective in every person. However, some general strategies do reduce the risk of cancer or cancer complications in many people. These general strategies fall into 3 categories:
Primary prevention: Steps people can take to lessen their chance of developing certain types of cancer
Secondary prevention: Directed at people who may already have some kind of cancer but have not developed symptoms
Tertiary prevention: Measures aimed at slowing down the effects of a cancer to prevent complications
Screening Screening tests Because many different diseases can cause the same symptoms, it can be challenging for doctors and other primary care practitioners to identify the cause. Doctors first gather basic information... read more is part of secondary prevention of certain cancers. It involves using information about a person, particularly their risk factors for cancer Risk Factors for Cancer Many genetic and environmental factors increase the risk of developing cancer. However, not all people who are exposed to carcinogens or who have other risk factors develop cancer. (See also... read more and results of their physical examination, to guide testing to look for unrecognized cancer. Early detection of cancerous or precancerous growths can save lives. So it is important that people get recommended screening tests for cancer Screening for Cancer Cancer is suspected based on a person's symptoms, the results of a physical examination, and sometimes the results of screening tests. Occasionally, x-rays obtained for other reasons, such as... read more . For example, Papanicolaou (Pap) tests Screening for Cervical Cancer Sometimes doctors recommend screening tests, which are tests that are done to look for disorders in people who have no symptoms. If women have symptoms related to the reproductive system (gynecologic... read more are a way to screen for cervical cancers Cervical Cancer Cervical cancer develops in the cervix (the lower part of the uterus). Most cervical cancers are caused by human papillomavirus (HPV) infection. Cervical cancer usually results from infection... read more by detecting precancerous changes in cells of the cervix. Colonoscopy is one of the screening tests for colorectal cancer Screening tests Family history and some dietary factors (low fiber, high fat) increase a person’s risk of colorectal cancer. Typical symptoms include bleeding during a bowel movement, fatigue, and weakness... read more . Removing precancerous colon polyps Polyps of the Colon and Rectum A polyp is a projecting growth of tissue from the wall of a hollow space, such as the intestines. Some polyps are caused by hereditary conditions. Bleeding from the rectum is the most common... read more found during screening can decrease the chance of developing colorectal cancer.
Lifestyle factors are the main reducible risk factors. The main factors include tobacco exposure, alcohol consumption, obesity, and preventable or avoidable infections (hepatitis B Hepatitis B, Chronic Chronic hepatitis B is inflammation of the liver that is caused by the hepatitis B virus and that has lasted more than 6 months. Most people with chronic hepatitis B have no symptoms, but some... read more , hepatitis C Hepatitis C, Chronic Chronic hepatitis C is inflammation of the liver that is caused by the hepatitis C virus and that has lasted more than 6 months. Hepatitis C often causes no symptoms until after it has badly... read more , and-, human papilloma viruses Human Papillomavirus (HPV) Vaccine The human papillomavirus (HPV) vaccine helps protect against infection by the strains of HPV that are most likely to cause the following: Cervical cancer, vaginal cancer, and vulvar cancer in... read more ). Reducing the risk of certain cancers may be possible through dietary and other lifestyle changes. How much risk can be reduced depends on the specific cancer.
Dietary changes Diet and Cancer Many studies have tried to determine whether specific foods increase or decrease a person's risk of getting cancer. Unfortunately, different studies have had conflicting results, so it is hard... read more reduce the risk of some types of cancer:
Decreasing alcohol intake can reduce the risk of head and neck, liver, and esophageal cancer.
Decreasing fat intake appears to reduce the risk of breast and colon cancers.
Limiting the intake of processed meat and increasing the intake of whole grains and fruits and vegetables may decrease risk of some types of cancer.
The way meat is cooked may also increase the risk of cancer. Grilling, broiling, or frying meats creates certain chemicals that have been linked to colon cancer. Using other cooking methods reduces the formation of these chemicals and may reduce the risk of colon cancer.
Tobacco use is directly associated with one third of all cancers. Not smoking and avoiding exposure to tobacco smoke can greatly reduce the risk of lung, kidney, bladder, head and neck, and several other cancer types. People who quit smoking Smoking Cessation While often very challenging, quitting smoking is one of the most important things smokers can do for their health. Quitting smoking brings immediate health benefits that increase over time... read more can also reduce their risk of cancer, and the risks decrease over time. People who avoid the use of smokeless tobacco (snuff or chew) decrease their risk of cancer of the mouth and tongue. Current smokers or people who have smoked within the past 15 years are candidates for lung cancer screening.
Being overweight or obese increases cancer risk, especially breast cancer, colon cancer, endometrial cancer, esophageal cancer, kidney cancer and pancreatic cancer. People should try to maintain a healthy weight through both diet and exercise. Physical activity itself may reduce the risk of breast, endometrial, and prostate cancers.
Carcinogens are substances that increase the risk of cancer. Some carcinogens, such as asbestos,benzene, and diesel engine exhaust may be present in the workplace, and workers in industries that use known carcinogens should take appropriate precautions to avoid or minimize exposure. Other carcinogens occur in the home or the environment. For example, radioactive elements that naturally occur in the earth decay into radioactive radon gas, which can collect inside the homes of people living in certain areas. Exposure to radon increases the risk of lung cancer, especially in people who smoke.
Avoiding sun exposure (especially during the middle of the day) can reduce the risk of skin cancers Overview of Skin Cancer Skin cancer is the most common type of cancer. Skin cancer is most common among people who work or play sports outside and among sunbathers. Fair-skinned people are particularly susceptible... read more . Covering exposed skin and using sunscreens with a sun protection factor (SPF) of at least 30 that protect against both ultraviolet A and ultraviolet B light also help reduce the risk of skin cancer.
Vaccines against cancer
Vaccines can prevent certain types of cancer that are caused by viruses. For example, certain strains of sexually transmitted human papillomavirus Human Papillomavirus (HPV) Vaccine The human papillomavirus (HPV) vaccine helps protect against infection by the strains of HPV that are most likely to cause the following: Cervical cancer, vaginal cancer, and vulvar cancer in... read more (HPV) cause cervical cancer, anal cancer, and some forms of head and neck cancer. Vaccination against HPV Human Papillomavirus (HPV) Vaccine The human papillomavirus (HPV) vaccine helps protect against infection by the strains of HPV that are most likely to cause the following: Cervical cancer, vaginal cancer, and vulvar cancer in... read more before the first sexual encounter can largely prevent many cases of these cancers.
As another example, infection with hepatitis B virus increases the risk of liver cancer. Vaccination against hepatitis B virus Hepatitis B Vaccine The hepatitis B vaccine helps protect against hepatitis B and its complications ( chronic hepatitis, cirrhosis, and liver cancer). Generally, hepatitis B is more serious than hepatitis A and... read more can help prevent liver cancer.
Aspirin use may reduce the risk of colorectal cancer or result in earlier diagnosis because of bleeding.
For women with symptoms of menopause Symptoms Menopause is the permanent end of menstrual periods and thus of fertility. For up to several years before and just after menopause, estrogen levels fluctuate widely, periods become irregular... read more , taking hormone therapy (for example, estrogen and progesterone) may increase the risk of breast cancer. Women who have symptoms of menopause should carefully consider the risks and benefits of using hormone replacement therapy and consult their health care professional (see also Hormone Therapy for Menopause Hormone Therapy for Menopause Menopause is the permanent end of menstrual periods and thus of fertility. For up to several years before and just after menopause, estrogen levels fluctuate widely, periods become irregular... read more ).
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
American Cancer Society: Information to help people reduce the risk of cancer