Are there factors that may modify the relationship between obesity and breast cancer risk?
below). These studies also examined risk among the subgroup of women who had never used postmenopausal hormone treatment to estimate more accurately the effects of obesity alone on breast cancer risk. Five cohort studies used this approach. These reports found about a doubling of postmenopausal breast cancer risk associated with BMI values above 30 among women who had never used hormone treatment. This is considered a moderate increase in risk. These are important results as cohort studies are considered most reliable, and all five studies reported a statistically significant increase in risk. They also reported a statistically reliable dose-response relationship for risk. This means that normal weight women had the lowest risk, overweight women had higher risk, and obese women had the highest risk. Is weight gain related to breast cancer risk? Since weight gained during adulthood is believed to be largely fat tissue, a number of studies have examined the effect of weight gain on breas
