Pre-diagnosis physical activity and mammographic density in breast cancer survivors.
OBJECTIVE
To investigate the association between physical activity (PA) and mammographic density in the year before diagnosis in a population-based sample of 474 women diagnosed with stage 0-IIIA breast cancer and enrolled in the Health, Eating, Activity, and Lifestyle Study.


METHODS
We collected information on PA during an interview administered at a baseline visit scheduled within the first year after diagnosis. Participants recalled the type, duration, and frequency of different PAs for the year prior to their diagnosis. Dense area and percent density were estimated, from mammograms imaged approximately 1 year before diagnosis, as a continuous measure using a computer-assisted software program. Analysis of covariance methods were used to obtain mean density across PA tertiles adjusted for confounders. We stratified analyses by menopausal status and body mass index (BMI) because these factors strongly influence density.


RESULTS
We observed a statistically significant decline in mammographic dense area (p for trend = 0.046) and percent density (p for trend = 0.026) with increasing level of sports/recreational PA in postmenopausal women with a BMI > or = 30 kg/m2. Conversely, in premenopausal women with a BMI < 30 kg/m2, we observed a statistically significant increase in percent density with increasing level of sports/recreational PA (p for trend = 0.037).


CONCLUSIONS
Both mammographic dense area and percent density are inversely related to level of sports/recreational PA in obese postmenopausal women. Increasing PA among obese postmenopausal women may be a reasonable intervention approach to reduce mammographic density.
Irwin
Melinda L
ML
Department of Epidemiology and Public Health, Yale School of Medicine, New Haven, CT 06520-8034, USA. melinda.irwin@yale.edu
Aiello
Erin J
EJ
McTiernan
Anne
A
Baumgartner
Richard N
RN
Baumgartner
Kathy B
KB
Bernstein
Leslie
L
Gilliland
Frank D
FD
Ballard-Barbash
Rachel
R
D000328:Adult; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013177:Sports; D017741:Survivors