Clinical Abstracts
With Comments by Adriane Fugh-Berman, MD
Exercise and Breast Cancer Risk
May 2000; Volume 2; 39
Source: Verloop J, et al. Physical activity and breast cancer risk in women aged 20-54 years. J Natl Cancer Inst 2000;92:128-135.
Design/Setting/Subjects: Data from a population-based, case-control study included 918 cases (aged 20-54) and 918 age-matched controls. Eighty-nine percent of cases and 89.5% of controls were premenopausal.
Outcome Measures: Associations be-tween breast cancer risk and physical activity at ages 10-12; ages 13-15; lifetime recreational activity; and title of longest held job.
Results: Women who had ever engaged in recreational physical activity had a reduced risk of breast cancer compared with inactive women (odds ratio [OR] = 0.70, 95% confidence interval [CI] = 0.56-0.88). Recreational activity before age 20 years, recreational activity within the five years prior to diagnosis, and recreational activity in the intermediate period were all associated with decreased risk, but no time period was superior to any other time period. Compared to inactive women, active women whose occupation involved £ 80% sedentary activities had a 39% reduction in the risk of breast cancer (OR = 0.58, 95%, CI = 0.38-0.90). No further decrease in risk was seen with long duration of physical activity or high frequency or intensity of activity during the active period.
Funding: Dutch Cancer Society and Praeventiefonds.
Comment: Exercise appears to be associated with decreased breast cancer risk. It’s probably not too late to start now, although in this study only 10% of all active women started recreational activity after 30, so it could not be determined whether reduction in breast cancer risk was associated with recreational activity started "later in adult life"—30 is later in adult life? (I’m showing my age here....)
The majority of previous studies examining the effect of recreational physical activity on breast cancer risk in premenopausal women have found that exercise decreases risk; studies are mixed on whether physical activity around the age of menarche is protective later in life. (Vigorously exercising preteens may have lower body fat, which theoretically could delay menarche—and later menarche is associated with a decreased risk of breast cancer.)
Still, I’m taking this current study as good news; personally, I’m never happy with studies that find out that something you did or did not do as a teenager affects your health prospects as an elder. Also, parents of teenagers have enough to worry about without fearing that if they don’t chase their kids off the couch and onto the running track, they’re missing the window of opportunity to protect them against breast cancer. Having said that, however, most women who are exercising as adults exercised earlier in life, so by example, encourage your kids to exercise.
May 2000; Volume 2; 39
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content