Protect the Heart to Defend Against Breast Cancer?

By: Eric Sabo
May 25, 2005?In the space of a week, breast cancer has gone from a serious concern to a problem that seems downright manageable. Findings from separate studies suggest that this common cancer might be effectively countered through either exercise, a low-fat diet or by taking cholesterol-lowering medications known as statins.
The latest study, published today in the Journal of the American Medical Association, found that breast cancer patients can live longer with their disease by walking the equivalent of one or more hours a week. Looking at some 3,000 registered nurses with breast cancer who underwent the same type of treatment, researchers found that those who exercised had a lower chance of dying from the disease than women who were mostly inactive.

The research follows studies that produced similarly heartening results. In one recent trial, researchers found that women who ate low-fat foods after being treated for breast cancer were less likely to see the disease return. Another study found that the millions of women who take statins for high cholesterol receive an additional benefit: these drugs appear to cut the risk for developing breast cancer in half.

Experts caution that this research is still unfolding, and it remains to be seen if such promising results will hold up in further studies. But the findings imply that interventions proven successful for heart disease may help against breast cancer?both diseases account for nearly 540,000 combined deaths in women a year.


At the moment, researchers say that the link between fighting heart disease and breast cancer is something of a coincidence. Exercise may help against breast cancer by lowering estrogen, while statin drugs might inadvertently block a common pathway associated with a range of different cancers.

"None of these have anything to do with heart disease." said Wendy Chen, MD, of the Brigham and Women?s Hospital and Dana-Farber Cancer Institute.

Even so, such heart-protecting measures may seem far more appealing than the current methods for preventing breast cancer. Other than a mastectomy, where a surgeon removes the breast, the only proven way to prevent the disease is to take Tamoxifen or a similar drug, which is associated with a higher risk of endometrial cancer.

Despite increased safety concerns about one of the statin drugs, Crestor (Editor?s note: In a previous version of this article, Lipitor was incorrectly identified as the drug of concern), most doctors view these treatments as exceptionally safe. Moreover, a healthy diet and exercise can hardly hurt. Is the path to a healthy heart the way to beat breast cancer?

Not necessarily, some experts say. While expressing optimism in the latest findings, specialists in breast cancer prevention argue that recent headlines might overstate what really works. "It?s important that we not say more than we know." said Lisa Schwartz, MD, of the Dartmouth Medical School and VA Outcomes Group. Chen added, "I would not use these as a substitute."
Steps to protect the heart could eventually prove to be safe and effective for breast cancer. But in the meantime, here?s what the latest findings show.

Exercise: Previous research has suggested that physical activity may prevent breast cancer. In the latest study, researchers from Boston looked at whether exercise could improve survival in women who already have the disease. The greatest benefits were seen from exercising 3 to 5 hours a week, which was associated with a 50 percent lower risk of dying from breast cancer over four years compared to women who were inactive. But the findings were based on an observational study, rather than a controlled trial. This makes it hard to tell if other factors, such as a healthy lifestyle, could account for the positive effect.

"You can never be sure" about this type of research, says Michelle Holmes, MD, of Brigham and Women?s Hospital and Harvard Medical School, who led the study, "That being said, exercise can only benefit you."


A low-fat diet: Drowned out by the low-carb craze, this out-of-fashion diet may be making a bit of a comeback. At the recent American Society of Clinical Oncology meeting, Rowan Chleblowski, MD, of the Los Angeles Biomedical Research Institute announced that women treated for breast cancer could lower risk their risk of recurrence by eating just 33 grams of fat a day. Compared to women who ate more than 50 grams of fat, the study showed that the low-fat group reduced their risk of breast cancer returning by 24 percent.

The study involved more than 2,400 women and was based on a controlled design rather than just observing the two groups. Nonetheless, the effects were too small to rule out whether other factors, such as losing weight, were responsible. "Low-fat diets have been less than impressive" at preventing breast cancer, says Chen. She says weight loss should be the goal, which is backed up by more evidence. What?s the possible harm of a low-fat diet? Forgoing favorite foods for little possible gain, says Schwartz. "How much do you feel like giving up for a small decrease in risk?" she asks.

Statins: Statins are some of the top-selling drugs and for good reason: they lower the so-called "bad" LDL cholesterol and reduce the risk of heart disease, one of the nation?s leading killers. How these drugs may help against breast cancer is still being determined.

Reviewing the medical records of nearly 40,000 women, researchers found that women who used statins were significantly less likely to develop breast cancer. Once again, however, these findings are based on an observational type of study. Indeed, other research has found that statins may not reduce the risk of breast cancer.

Like all drugs, statins come with side effects. A growing concern has been muscle and kidney problems that seem more common with specific statins. The Food and Drug Administration pulled one statin from the market in 2001 and recently added warnings about a second one, Crestor. Until more is known, Schwartz says women should "remain skeptical."

http://womens_health.healthology.com...tatins&spg=FLA