- Sustained weight loss in women age ≥50 years was associated with up to 32% lower risk for postmenopausal breast cancer in a pooled analysis.
Why this matters
- Excess body weight has long been tied to breast cancer risk, but this study is the first to assess the effect of sustained weight loss in breast cancer risk reduction.
- Findings suggest that postmenopausal women with overweight or obesity should be encouraged to lose weight.
- Prospective observational study pooling 10 cohorts (United States, Australia, Asia) of women age ≥50 years in the Pooling Project of Prospective Studies of Diet and Cancer (n=180,885).
- Weight was assessed in 2 intervals over a 10-year period, and breast cancer incidence was determined in a follow-up period over the next 8 years.
- Sustained weight loss was defined as ≥2 kg lost in interval 1 that was not regained in interval 2.
- Funding: NIH; Australian National Health and Medical Research Council; others.
- Women with sustained weight loss vs stable weight and not using postmenopausal hormone had a linear reduction in breast cancer risk (HRs; 95% CIs):
- >2-4.5 kg lost: 0.82 (0.70-0.96);
- ≥9 kg lost: 0.68 (0.50-0.93).
- Observational design.