Everyday Changes to Reduce Cancer Risk

Researchers are still working to figure out why some people get cancer and some do not. As already noted, sometimes heredity is to blame. In other cases, it appears that cancer results from a complex interplay of different factors, such as:

• The environment: chemicals and other substances in the air you breathe and the foods you eat and drink
• Lifestyle choices: such as whether or not you smoke or how much you expose your skin to the sun
• An individual's own genetic makeup: how well your cells can repair or "fight off" damage from the outside world

Everyone is at risk for cancer, regardless of whether or not he or she has a family history. Statistics suggest that one in two American men and one in three women will be diagnosed with cancer during the course of their lifetimes.

You cannot control the genes you were born with or your environment, but you can take some steps in your everyday life to reduce cancer risk. Although these steps offer no guarantee against developing cancer, studies suggest they can make a difference.

Quit Smoking/Tobacco Use 
Reduce Sun Exposure and Tanning 
Practice Safe Sex/Consider Vaccination 
Make Careful Decisions About Hormone Replacement Therapy 
Control Your Weight and Diet/Exercise Regularly 

Quit Smoking/Tobacco Use

Quitting smoking, ending tobacco use, and avoiding secondhand smoke are the most important steps you can take to reduce your risk of cancer. Hundreds of studies have confirmed the association between smoking and many different types of cancer, the most common being lung cancer.

• Smoking causes 87 percent of lung cancer deaths. Lung cancer is the leading cause of cancer death in men and women. Scientists have observed that, when smoking rates in this country go up or down, lung cancer death rates go up or down as well.
• Smoking also is responsible for more than 30 percent of all cancer deaths annually in the United States. In addition to causing lung cancer, it causes most cancers of the mouth, larynx, pharynx, esophagus, and bladder. Smoking also is strongly associated with cancers of the pancreas, cervix, and stomach, as well as a type of blood cancer called acute myeloid leukemia.

Using smokeless tobacco, such as chewing tobacco or oral snuff, increases the risk of cancers inside the mouth. These typically affect the lip, tongue, cheeks, gums, and floor and roof of the mouth.

Secondhand smoke exposure—smoking yourself, but living or working around people who do—also is a known risk factor for lung cancer and nasal sinus cancer. Some research suggests that it also may increase risk for cancers of the cervix, breast, and bladder.

What You Can Do: If you smoke or use smokeless tobacco, resolve to quit. If you live with a smoker, try to get him or her to quit, or at least to restrict smoking to outside the home. Talk to your doctor about the various strategies that are available, from support programs to over-the-counter and prescription medications.

Reduce Sun Exposure and Tanning

Skin cancer is the most common type of cancer in the United States. More than 1 million cases are diagnosed in this country every year—that is more than all cancers of the prostate, breast, lung, colon, uterus, ovaries, and pancreas combined. There are two main types of skin cancer:

• Nonmelanoma (includes basal cell and squamous cell cancers). Typically, they are found on the parts of the body that tend to get the most sun exposure, such as the head and neck. They rarely spread to other parts of the body and are not likely to be fatal.
  
• Melanoma. This is a less common but much more serious form of skin cancer. If not caught early, it can spread to other parts of the body, making it much more difficult to treat.

The ultraviolet (UV) rays given off by the sun, sun lamps, and tanning beds increase risk for both types of skin cancer. Sunburns are believed to be particularly dangerous, but any ongoing UV exposure can increase skin cancer risk. If you have fair skin, your skin burns easily, and/or you have multiple moles on your body, you may be at greater risk of developing skin cancer.

What You Can Do: Take precautions to limit your amount of exposure to UV rays. For example, you can:

• Limit direct sun exposure during the midday hours, between 10 a.m. and 4 p.m. This is when the sun's rays are strongest. Plan activities out of the sun during these times.
• Wear clothing to protect your skin from the sun as much as possible. Tightly woven fabrics are best, and some even have special coatings to absorb UV rays. Try wearing a hat with a two- to three-inch brim or a shade cap, which looks like a baseball cap with draping down the sides and back. Clothing affords more reliable protection than sunscreen. Use a sunscreen with a Sun Protection Factor (SPF) of 15 or higher. Apply it generously to all areas of your skin not covered by clothing. Reapply at least every 2 hours, and more frequently if you are swimming or sweating.
• Avoid tanning beds and sunlamps. These give off UV rays as well, so they are not a safe tanning alternative.

Practice Safe Sex/Consider Vaccination

Virtually all cases of cervical cancer—cancer that develops in the cervix, or the lower necklike opening of a woman's uterus—can be traced to infection with the human papillomavirus, or HPV, which spreads through sexual contact. According to the Centers for Disease Control and Prevention, about 20 million people in the United States are infected with HPV, and by age 50, at least 80 percent of women with the virus have had an HPV infection. In most cases, the infection goes away on its own, but sometimes it leads to cancer.
 
Any woman who is or ever has been sexually active is at risk for HPV— for spreading it to other partners. Your risk increases if you:

• Started having sex at a young age (under 25)
• Have had or do have multiple sexual partners
• Have had other sexually transmitted diseases

However, even one encounter with an infected partner can cause HPV infection.

What You Can Do: You can protect yourself against HPV by abstaining from sex or having sex only with an uninfected partner who is also monogamous (that is, only having sex with you). Condoms also afford some protection against HPV transmission. Because HPV is so common, however, you may wish to consider being tested for the virus; see the later section on Regular Cancer Screenings for more information.

The Food and Drug Administration recently approved an HPV vaccine for girls and women aged 9 to 26. The vaccine protects against infection with two strains of HPV that are associated with the development of cervical cancer. It is most effective if given before a young woman becomes sexually active. Although the vaccine is believed to greatly reduce cervical cancer risk, it cannot eliminate that risk entirely. Regular screening for cervical cancer is still recommended.

Make Careful Decisions About Hormone Replacement Therapy

After menopause (cessation of menstrual periods, usually occurring around 50), some women take hormone replacement therapy to relieve common symptoms, such as hot flashes, vaginal dryness, and decreased sex drive. This therapy replaces one or both of the main female hormones, estrogen and progesterone, which are produced in much smaller amounts by the body after menopause. Estrogen replacement therapy (ERT) raises estrogen levels in the body by giving women synthetic (man-made) versions of this hormone alone. Combined hormone replacement therapy (HRT) uses both estrogen and progestin (progesterone-like hormone).

Some research has suggested that women should limit their use of hormone replacement therapy because it can increase their risk for certain cancers. The cancers that are of greatest concern include:

• Endometrial cancer (cancer of the uterine lining): The use of ERT (estrogen-alone therapy) increases a woman's risk of developing endometrial cancer. Prolonged use of vaginal creams or rings containing estrogen may also increase estrogen levels in the body. Combined HRT has not been found to raise this risk. Therefore, women who have not undergone hysterectomy (removal of the uterus) should choose HRT over ERT.
• Breast cancer: Results from a recent large study called the Women's Health Initiative suggest that daily use of combined HRT increased a woman's chances of developing breast cancer by about 25 percent if she took it for several years. (This means that her lifetime risk would go from about 13.2 percent to 16.5 percent.) Women who took this combined HRT also had a higher risk of having breast cancer detected at a more advanced stage and were more likely to have abnormal results on mammograms.
• Ovarian cancer: Some studies have suggested that women who take ERT, particularly for more than 10 years, have a higher risk for ovarian cancer. The risk increases with longer ERT use. The Women's Health Initiative study also found an association between HRT use and ovarian cancer risk.

What You Can Do: Make decisions about whether or not to use hormone replacement carefully, in close consultation with your doctor. Although some studies have suggested that ERT and HRT raise cancer risk, there is still much more research to be done on how the various types of therapy affect women of different age groups. Also, the same large study that found an association between HRT and increased breast cancer risk found that the therapy decreases risk for colorectal cancer and osteoporosis (thinning of the bones).

You and your doctor must consider your own individual preferences, medical history, and menopausal symptoms. If you have a strong family history of breast, ovarian, and/or endometrial cancer, this also needs to be taken into account.

Control Your Weight and Diet/Exercise Regularly

Some studies have suggested that certain lifestyle choices, such as maintaining a healthy weight and exercising regularly, can decrease risk for some types of cancer. Lack of physical activity has been associated with increased risk for colon and breast cancer, and possibly other cancers. There is some evidence that people who are overweight are at increased risk for cancers of the colon, breast, endometrium, and possibly other parts of the body.

Diet, too, has been found to influence cancer risk, although these findings are still considered preliminary. For example, some studies have linked alcohol with increased risk for cancer of the mouth, esophagus, and breast. Others have suggested that eating fruits and vegetables helps reduce cancer risk, although this is still under investigation.

What You Can Do: The American Cancer Society makes the following lifestyle recommendations for reducing cancer risk:

• Maintain a healthy weight, or achieve a healthy weight if you are already overweight or obese. Your Body Mass Index (BMI), a number calculated using your height and weight, is a good gauge for whether your weight is healthy or not. Generally, a BMI under 25 is considered normal. Calculate your BMI here. 
• Exercise regularly. Adults should engage in at least 30 minutes of moderate to vigorous physical activity, above usual activities, on 5 or more days of the week. Even more physical activity—45 to 60 minutes—preferable. Children and teens should engage in at least 60 minutes per day of moderate to vigorous physical activity at least 5 days per week.
• Eat a healthy diet, with an emphasis on food from plant sources. Eat five or more servings of a variety of vegetables and fruits every day. Choose whole grains in preference to processed (refined) grains; for example, this means choosing wheat bread over white, or brown rice over white. Limit your consumption of processed and red meats. And in general, limit portion sizes to control your weight.
• If you drink alcoholic beverages, limit your consumption. Men should have no more than two drinks per day, and women, no more than one.

Consult with your doctor to get help in following these recommendations.