Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Cancer Causes Control. 1998 Aug;9(4):433-9.

Physical activity and breast cancer risk in the College Alumni Health Study (United States).

Author information

  • 1Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, USA.

Abstract

OBJECTIVES:

It is unclear whether physical activity is associated with a reduced risk of breast cancer. Some studies also suggest different effects between pre- and postmenopausal women, and lean and heavy women.

METHODS:

We followed 1,566 University of Pennsylvania alumnae (mean age, 45.5 years), initially free of breast cancer, from 1962 until 1993. Physical activity at baseline was assessed by asking women about stairs climbed, blocks walked, and sports played. We estimated energy expenditure and categorized women into approximate thirds (< 500, 500-999, 1,000+ kcal/wk). We identified 109 breast cancer cases during 35,365 person-years from follow-up questionnaires or from death certificates.

RESULTS:

After adjustment for age and body mass index (BMI) (kg/m2), the relative risk (RR) of breast cancer was 0.92 (95 percent confidence interval [CI] = 0.58-1.45) among women expending 500-999 kcal/wk and 0.73 (CI = 0.46-1.14) for those expending 1,000+ kcal/wk, compared with women expending < 500 kcal/wk (P trend = 0.17). This association was modified by menopausal status, but not BMI. For postmenopausal women, corresponding RRs were 0.95 (CI = 0.58-1.57) and 0.49 (CI = 0.28-0.86), respectively (P trend = 0.015). Increased physical activity in premenopausal women was not significantly associated with decreased risk of breast cancer.

CONCLUSIONS:

These data support an inverse association between physical activity and breast cancer among postmenopausal women.

PMID:
9794176
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Write to the Help Desk