Exercise and Breast Cancer

Studies on positive effect of exercise on preventing breast and colon cancer are promising, but fall short of declaring reduced risk for those working out; Dr Anne McTiernan of Fred Hutchinson Cancer Research Center and author of book Breast Fitness: An Optimal Exercise and Health Plan for Reducing Your Risk of Breast Cancer, compares exercise to wearing seat belt; says that exercise gives person additional protection, but does not guarantee safety from cancer.


Bernyce Edwards's daughter was 42 in 1997 when she died of breast cancer. It was just 69 days from diagnosis to death. And through her shock and grief, Ms. Edwards had a terrible worry: what if she got breast cancer, too?

"That's my biggest fear," she said.

So, to protect herself, she has taken up exercise.

And not just any exercise. This 73-year-old woman has turned into an exercise zealot.

She walks, she runs, she leaves her house in Bellingham, Wash., as early as 5 a.m. and spends an hour every day, rain or shine, putting in the miles on the trails and around a lake.

But will her efforts help? Medical researchers agree that, at the very least, regular exercise can make people feel better and feel better about themselves.

There is less agreement on whether it can also prevent cancer. But for two types, the evidence is promising: breast cancer and cancer of the colon. Other cancers have not been studied, or the studies that have been done have yielded little evidence that exercise can help.

Even for breast and colon cancer, further confirmation is needed.

Researchers who are enthusiastic about a cancer-exercise connection also caution against too much enthusiasm.

Exercise is like a seat belt, says Dr. Anne McTiernan of the Fred Hutchinson Cancer Research Center in Seattle, a co-author of "Breast Fitness: An Optimal Exercise and Health Plan for Reducing Your Risk of Breast Cancer."

"It's not a guarantee, but it can reduce your risk," Dr. McTiernan said. "The negative side is when a person says, 'The reason I got cancer is that I didn't exercise.' That's the problem."