"We found a beneficial effect on survival for exercise undertaken in the year before diagnosis, particularly among women who were overweight or obese near the time they were diagnosed with breast cancer," said Dr. Page E. Abrahamson of the Fred Hutchinson Cancer Research Center in Seattle.
The study published in the journal Cancer looked at the survival rates of 1,264 women between the ages of 20 and 54 diagnosed with breast cancer between 1990 and 1992, as well as their level of physical activity prior to diagnosis. The researchers talked to the women within several months of diagnosis, and asked them to report on their exercise levels at ages 13, 20 and the 12 months before they were diagnosed with breast cancer.
During the eight to 10 years the women were followed, 290 women died. The study results showed the lower survival rates coincided with women who reported the lowest levels of physical activity. The women who reported the highest amount of physical activity during the 12 months leading up to their diagnosis had a 22 percent lower risk of death when compared to women who reported the lowest amount of exercise, even when the disease's stage and the patients' income level were factored in.
Women who reported high levels of activity, but were overweight or obese at the time of diagnosis showed a 30-percent reduction in mortality risk. The researchers added that more research is needed on the relationship between exercise and breast cancer, as their report is only one of a handful on such studies.
"If future research confirms that physical activity improves survival among women with breast cancer, programs and policies to promote such activity for this purpose may be adopted," Abrahamson said.
According to Abrahamson and colleagues, few modifiable lifestyle factors had been linked with improving breast cancer prognosis in the past, and the improving survival rates are generally attributed to earlier detection and improved treatment options.