Physical activity and breast cancer risk in hispanic and non-hispanic white women.
To investigate breast cancer risk in Hispanic and non-Hispanic White women, the authors conducted a population-based case-control study of New Mexican women during 1992-1994 using incident breast cancer cases aged 35-74 years and frequency-matched controls selected using random digit dialing. Activity type and weekly duration of usual nonoccupational physical activity were used to calculate weekly metabolic equivalent (MET)-hours of total and vigorous physical activity (> or =5 METs). Conditional logistic regression models were fitted to estimate the relative risk of breast cancer for levels of physical activity and to assess the difference in effects by ethnicity, body mass index, energy intake, and menopausal status. Vigorous physical activity was associated with reduced breast cancer risk in both Hispanic and non-Hispanic White women. Women in the highest category of vigorous activity had lower risk of breast cancer (adjusted odds ratio = 0.34, 95% confidence interval: 0.22, 0.51 for Hispanic; adjusted odds ratio = 0.60, 95% confidence interval: 0.41, 0.89 for non-Hispanic White women) compared with women reporting no vigorous physical activity. Both pre- and postmenopausal Hispanic women showed decreasing risk with increasing level of activity. Physical activity was protective only among postmenopausal non-Hispanic White women. The effects of physical activity were independent from reproductive factors, usual body mass index, body mass index at age 18, adult weight gain, and total energy intake.
Gilliland
F D
FD
Division of Occupational and Environmental Health, Department of Preventive Medicine, and Norris Comprehensive Cancer Center, University of Southern California Health Sciences Center, Los Angeles, CA, USA.
Li
Y F
YF
Baumgartner
K
K
Crumley
D
D
Samet
J M
JM
D000328:Adult; D000368:Aged; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D015986:Confounding Factors, Epidemiologic; D002149:Energy Intake; D015444:Exercise; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D016013:Likelihood Functions; D016015:Logistic Models; D008875:Middle Aged; D009516:New Mexico / Q000453:epidemiology; D012042:Registries; D012307:Risk Factors; D011795:Surveys and Questionnaires; D044465:White People / Q000706:statistics & numerical data*