Preventing cancer

Low-dose daily aspirin may help reduce your risk of colon cancer and other malignancies. But even if future research doesn't confirm this hope, there are other ways you can protect yourself and your family. Here are 10 tips:

1. Avoid tobacco in all its forms, including exposure to secondhand smoke.

2. Eat properly.  Reduce your consumption of saturated fat, processed meat, and red meat, which appear to increase the risk of colon and prostate cancers. Limit your intake of charbroiled foods (especially meat), and avoid deep-fried foods. Increase your consumption of fruits, vegetables, and whole grains; although other reports are mixed, two large 2003 studies found that high-fiber diets may reduce the risk of colon cancer. And don't forget to eat fish two to three times a week; you'll get protection from heart disease, and you may reduce your risk of prostate cancer.

3. Exercise regularly.  Physical activity has been linked to a reduced risk of colon cancer, and it may even help prevent prostate cancer. Exercise also appears to reduce a woman's risk of breast cancer and possibly reproductive cancers.

4. Stay lean.  Obesity increases the risk of many forms of cancer. Calories count; if you need to slim down, take in fewer calories and burn more with exercise.

5. If you choose to drink, limit yourself to one to two drinks a day.  Excess alcohol increases the risk of cancers of the mouth, larynx (voice box), esophagus (food pipe), liver, and colon, especially in smokers; it also increases a woman's risk of breast cancer. Smoking further increases the risk of many alcohol-induced malignancies.

6. Avoid unnecessary exposure to radiation.  Get medical imaging studies only when you need them, and ask your doctor to choose the test that will provide the information he needs with the lowest radiation dose. Check your home for residential radon, which increases the risk of lung cancer. Protect yourself from ultraviolet radiation in sunlight, which increases the risk of melanomas and other skin cancers.

7. Avoid exposure to industrial and environmental toxins  such as asbestos fibers, benzene, aromatic amines, and polychlorinated biphenyls (PCBs).

8. Avoid infections  that contribute to cancer, including hepatitis viruses, HIV, and the human papillomavirus.

9. Get enough vitamin D.  Many experts now recommend 800 to 1,000 IU a day, a goal that's nearly impossible to attain without taking a supplement. Although protection is far from proven, evidence suggests that vitamin D may help reduce the risk of prostate cancer, colon cancer, and other malignancies. And even if these hopes don't pan out, vitamin D should help keep your bones strong and may also reduce your risk of falling.

10. Don't count on other supplements.  Careful studies show that selenium, vitamins C and E, beta carotene, folic acid, and multivitamins are not protective, and that some may do more harm than good.

Chemoprevention

A healthful lifestyle can sharply reduce your risk of getting cancer, but it takes thought and effort. Wouldn't it be nice if there were a pill for protection? The concept is called chemoprevention, and aspirin is a hopeful, but still unproven, example of a medication that may reduce cancer risk.

Another example applies to breast cancer. A randomized clinical trial of tamoxifen versus placebo in high-risk women showed that five years of treatment reduced the risk of breast cancer by about 50%. But there was a price to pay, including an increase in uterine cancer and blood clots. Based on this study, the FDA has approved tamoxifen for the prevention of breast cancer, but only in high-risk women.

Breast cancer is a hormonally responsive disease, and tamoxifen works because it's an anti-estrogen. Prostate cancer is also driven by sex hormones — and two drugs that block the conversion of the male hormone testosterone to dihydrotestosterone, the hormone that's active in the prostate, appear to reduce the risk of prostate cancer. But finasteride (Proscar, generic) and dutasteride (Avodart) also come with a price. Many men would gladly put up with uncommon, if troublesome, side effects such as sexual dysfunction, but while the drugs appear to reduce the risk of tame, low-grade prostate cancers, they also seem to increase the risk of high-grade, aggressive prostate cancers — which is why the FDA has approved them to treat benign prostatic hyperplasia but not to prevent prostate cancer.