NEW YORK - Recreational physical activity in the
year before a diagnosis of breast cancer seems to have a positive influence on
the prognosis of young women who are overweight or obese when they are
diagnosed, new research suggests.
"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," Dr. Page E. Abrahamson of the Fred
Hutchinson Cancer Research Center in Seattle told Reuters Health.
The finding is encouraging, Abrahamson and colleagues note in the journal
Cancer, because few modifiable lifestyle factors for improving a breast cancer
prognosis have been identified.
Although survival rates for breast cancer generally are improving due to
earlier detection and better treatments, "breast cancer patients are eager to
know what they can do to enhance their survival," Abrahamson said.
Abrahamson and a multicenter U.S. team investigated the ties between
prediagnosis physical activity and survival in 1,264 women, between 20 and 54
years old, who were diagnosed with breast cancer between 1990 and 1992.
Within several months of diagnosis, the women were asked about their average
frequency of moderate and vigorous physical activity at age 13 years, age 20
years, and during the 12 months before diagnosis.
Two hundred ninety women died during the 8 to 10 years they were followed.
Data analysis showed that women reporting the lowest levels of activity had
consistently lower survival rates throughout follow-up.
After accounting for stage of disease and income level, the researchers
observed a modest overall reduced death risk of 22 percent among women in the
highest quartile of activity in the year before their diagnosis compared with
women in the lowest quartile of activity.
High activity levels were associated with a 30-percent reduction in the risk
of death among women who were overweight or obese at the time of diagnosis.
No relationship was observed between mortality risk and physical activity
levels among women who were underweight or at their ideal weight at the time of
diagnosis. Physical activity at age 13 or age 20 also had no impact on survival
in this study.
While exercise has been shown to be a significant factor in preventing breast
cancer, this study is one of only a handful to look at the impact of physical
activity on breast cancer survival. "More research in this area is warranted,"
Abrahamson said.
"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," she added.
SOURCE: Cancer, October 15, 2006.
