May 7, 2003 -- Breast cancer survivors who begin an exercise regimen soon after completing treatment not only improve their fitness levels, but their mental outlook as well. Survivors who exercised regularly while taking part in a Canadian study reported more hours of happiness a week and better self-esteem compared with those who did not exercise.
Regular exercise has been shown to help protect women against breast cancer, but its benefits in those who have been treated for the disease are less clear. Breast cancer survivors can develop heart and lung problems from the disease itself, from the drugs used to treat it, or from weight gain and inactivity during treatment. And there has been some concern about the safety of exercise immediately following treatment.
"There are currently no guidelines saying patients should or should not exercise following breast cancer treatment, so I don't think it is even brought up with most patients," physical education professor Kerry S. Courneya, PhD, tells WebMD. "Because patients often feel fatigued after chemotherapy and radiation, they are often less active that normal."
In their study, Courneya and colleagues from the University of Alberta compared outcomes among 25 postmenopausal breast cancer survivors placed on an exercise program and 28 survivors who did not exercise. Their findings are reported in the May issue of the Journal of Clinical Oncology.
The women were recruited for the study between six and 18 months following completion of breast cancer treatment. The exercise group trained on special stationary bikes that recorded lung and heart function. They worked out three times a week for 15 weeks, and progress was determined through peak oxygen consumption measurement and standardized quality-of-life surveys.
Fitness levels for both the exercise and non-exercise groups were similar at the beginning of the study but improved dramatically in the women who exercised. Peak oxygen consumption -- a measure of fitness -- improved by 17% in the exercise group and declined by 3% in the women who didn't exercise.
Overall quality of life increased by nine points on a quality-assessment scale in the exercisers, compared with almost no increase in the non-exercisers. The increase, Courneya says, was larger than that typically seen for other interventions aimed at breast cancer survivors, including group therapy, individual counseling, and music or art therapy.
However, exercisers also experienced more lymphedema than non-exercisers.
"The increase in physical and functional well-being was expected, but many women also reported improvements in self-esteem," Courneya says. "They just felt a lot better about themselves. Cancer makes people feel like their bodies have failed them, but exercise shows them they are still strong and capable."
The study's small size means that its findings must be confirmed in a larger number of survivors, but Courneya says the current evidence is strong enough to recommend regular exercise following breast cancer treatment.
Yale University epidemiologist Melinda L. Irwin, PhD, who also studies the effects of exercise on cancer risk and survival, agrees.
Last month, Irwin published a study showing that women are less inclined to exercise following a diagnosis of breast cancer, regardless of their activity level beforehand. She says the benefits of regular exercise are too great to ignore.
"In an effort to decrease obesity, prevent post-diagnosis weight gain, and improve cancer prognosis, participation in physical activity after a diagnosis of cancer should be recommended by clinicians and healthcare providers," she tells WebMD.