WEDNESDAY, Sept. 7, 2022 (HealthDay News) -- Greater overall physical activity, greater vigorous activity, and lower sedentary time seem likely to reduce the risk for breast cancer, according to a study published online Sept. 6 in the British Journal of Sports Medicine.
Suzanne C. Dixon-Suen, from the Cancer Council Victoria in Melbourne, Australia, and colleagues performed two-sample inverse-variance-weighted Mendelian randomization using individual-level Breast Cancer Association Consortium case-control data from 130,957 women of European ancestry (69,838 invasive cases) and 91,105 to 377,234 women from the U.K. Biobank. Genetic instruments were single nucleotide polymorphisms associated with wrist-worn accelerometer-measured overall physical activity or sedentary time or accelerometer-measured or self-reported vigorous physical activity.
The researchers observed an association for greater genetically predicted overall activity with a lower risk for breast cancer overall (odds ratio, 0.59 per standard deviation) and for most case groups defined by tumor characteristics. There was an association for genetically predicted vigorous activity with a lower risk for pre/perimenopausal breast cancer (odds ratio, 0.62 for three or more versus zero self-reported days); for most case groups, estimates were consistent. There was an association observed for greater genetically predicted sedentary time with a higher risk for hormone-receptor-negative tumor (odds ratio, 1.77 per standard deviation [~7 percent time spent sedentary]); in most case groups, estimates were elevated.
"A stronger cancer-control focus on physical activity and sedentary time as modifiable cancer risk factors is warranted, given the heavy burden of disease attributed to the most common cancer in women," the authors write.
Several authors disclosed financial ties to the biopharmaceutical industry.