The largest study of its kind conducted worldwide, and the first ever in Canada, the Alberta Physical Activity and Breast Cancer Prevention (ALPHA) Trial was a randomized controlled trial designed to examine how a one-year intervention of moderate-to vigorous-intensity exercise (45-minute sessions, 5 days per week) influences several intermediate endpoints for breast cancer, including mammographic density, endogenous estrogens, insulin levels, insulin-like growth factors, body composition, and physical fitness levels, in 320 postmenopausal women. One-year of follow-up after the exercise intervention was also conducted. An extension of the ALPHA Trial, the ALPHA Ancillary Study, examined endogenous androgens and biomarkers of obesity and inflammation, including adiponectin, C-reactive protein, insulin, leptin, TNF-α, and interleukin-6, which have recently been proposed as important biomarkers involved in the association of physical activity and breast cancer. An additional ancillary study examined the role of oxidative stress, anti-oxidant enzymes and anti-inflammatory cytokines, telomere length as additional evidence on other pathways that may explain how exercise influences breast cancer risk.
Co-Principal Investigator: Dr Kerry Courneya
Co-Investigators: Dr Anne McTiernan, Dr Rachel Ballard-Barbash, Dr Melinda Irwin, Dr Norman Boyd, Dr Martin Yaffe, Dr Susan Lees-Miller, Dr Tara Beattie, Dr John McIntyre, Dr Will King
Funders: Canadian Breast Cancer Research Alliance and Canadian Institutes of Health Research