Scientists have been trying for decades to understand cancer. What makes normal cells start to change, divide and invade the body? And what can be done to prevent this process?
A lot about cancer is still a mystery. Doctors often aren't sure why one person who has never smoked a cigarette may get lung cancer when a longtime smoker may not.
Research has taught us a lot. We know that cancer in its many forms is most likely a result of several factors working together. We know that cancer can develop over a number of years. And we know that certain factors are known to raise your risk of cancer.
Factors you can't control
Some things that put you at risk for cancer are out of your control. You can't change your:
- Genetics and family history
All of these can be risk factors for various cancers.
Here is the good news
You can do many things to help cut your risk of cancer through the choices you make about your behaviors. Let's look at some risk factors that may be in your power to control.
Smoking causes almost one third of all U.S. cancer deaths. Cigarettes are full of cancer-causing ingredients. Smokers are 15 to 30 times more likely to get lung cancer or die from it than non-smokers. And tobacco can cause cancers almost anywhere in the body.
You may think occasional smoking is harmless. It's not. Even a few cigarettes a day increases the risk of lung cancer. And when people around you breathe in your smoke, it's like they're smoking, too. Secondhand smoke is believed to cause thousands of deaths a year.
Smokeless tobacco such as chewing tobacco or snuff also contains cancer-causing chemicals. It too has been linked to several forms of cancer.
Tobacco use is still one of the biggest health challenges in America, despite all the compelling research and public awareness efforts. It's hard to quit, but millions of people have managed to do it.
Diet, physical activity and weight
Experts believe many cancers can be traced to a poor diet, lack of physical activity and being overweight or obese. Increasing physical activity can help reduce or control weight. It may also lower your risk for some cancers and other chronic diseases. Check with your doctor about an activity level that is right for you.
The link between cancer and diet is still being studied. Experts say eating a healthy diet rich in fruits, vegetables and whole grains may help cut your risks of getting certain cancers.
Many studies have linked regular drinking of alcohol with various forms of cancer. If you choose to drink, the Dietary Guidelines for Americans advises moderation. This means up to one drink per day for women and two drinks per day for men. This is only for those adults of legal drinking age and for whom it is safe to drink. Even a few drinks a week is linked with a higher risk of breast cancer for women.
Screenings are tests that check for the presence of a disease or condition. Early detection may result in better outcomes in people with cancer.
Certain people are more at risk for cancer. Your doctor may look at your family history, age, lifestyle, environmental factors and other conditions to recommend the best screenings at the best times for you.
Experts recommend screenings for breast, colorectal and cervical cancer. Screenings for lung, ovarian, prostate and skin cancers have not been shown to reduce deaths from those cancers, according to health experts.
Exposure to radiation
Radiation comes from many sources. You may first think of medical X-rays and tests. But don't overlook radon gas that can be found in many homes. Exposure to radon has been linked to lung cancer. Experts recommend testing your home for radon and making repairs if it is detected.
Exposure to the sun's ultraviolet (UV) rays can cause skin cancer. Skin cancer is the most common form of cancer in America. Always take steps to protect your skin from damaging radiation when you are in the sun. Stay in shaded areas when you can, apply sunscreen with a protective factor of SPF 15 or higher and wear protective clothing, sunglasses and a hat.
Indoor tanning also produces radiation. Using sunlamps or tanning beds or booths can lead to melanoma, the deadliest skin cancer, and other forms of skin damage and cancer.
Doctors have linked certain things in the environment to cancer. For instance, working around asbestos raises your risk of lung cancer, particularly for smokers. It is important to minimize your exposure to hazardous environmental substances. Be sure your doctor has a clear picture of your home and work environment and is aware of any known exposures.
The risk of getting some types of cancer can be inherited. The risk is passed along from one or both parents through genes, chromosomes or proteins. Genetic testing can reveal whether you carry certain abnormal genes that put you at higher risk of cancer.
Genetic testing may be recommended in cases in which three conditions are met:
- When there is a personal or family history that suggests an inherited cancer risk
- When the test can clearly reveal the presence or absence of a genetic risk
- When the test results provide information that can help guide a person's future medical care or medical choices
Some viruses and infections have been linked to cancer. Scientists have developed vaccines to guard against a few of these. The vaccine for human papillomavirus (HPV) helps prevent some cervical and related cancers. The vaccine for hepatitis B can cut the risk for liver cancer.
Some types of hormone therapy used to relieve symptoms of menopause in women carry an increased risk of breast cancer. Talk with your doctor about pros and cons of hormone therapy if you are considering it. The U.S. Food and Drug Administration advises women to give great thought to using hormones. If you decide to use them to control menopause symptoms, use the smallest dose for the shortest amount of time. Only stay on them until you no longer have symptoms of menopause.
Can you identify some areas of your lifestyle where you could take steps to lower your cancer risk? Maybe it's getting more exercise or modifying your diet. Talk with your doctor about how you might change some of your habits or activities to lead a healthier life.
Created on 02/11/2002
Updated on 09/10/2013
- National Cancer Institute. Cancer prevention overview.
- Centers for Disease Control and Prevention. Cancer prevention and control. Other ways to reduce cancer risk.
- Health.gov. Dietary guidelines for Americans 2010.
- National Cancer Institute. Cancer trends progress report 2011-2012.