Lifetime physical activity and risk of breast cancer

We conducted a case-control study of 394 women with breast cancer and 788 c ontrol women (91% response) to investigate the association of lifetime phys ical activity with mainly menopausal breast cancer risk. After controlling for potential confounders, the odds ratios (95% confidence intervals) for i ncreasing quartiles of lifetime physical activity were 1.00 (referent), 0.9 1 (0.60-1.37), 0.91 (0.60-1.39), and 1.10 (0.73-1.67), respectively; P, tre nd = 0.47. We also separately examined physical activity at ages 12-18, 19- 34, 35-49 and greater than or equal to 50 years; no significant trends were observed in any age group. These data do not support a role of physical ac tivity in preventing breast cancer. (C) 2001 Cancer Research Campaign http: //www.bicancer.com.