Weight loss after bariatric surgery may reduce risk of developing breast cancer

Key clinical point: Weight loss after bariatric surgery reduced the risk of developing breast cancer (BC) in women with prior obesity to a level equivalent to that in women with a body mass index (BMI) of <25 kg/m².

Major finding: After a 1-year washout period, women who did vs did not undergo bariatric surgery had significantly reduced BC risk (hazard ratio [HR] 1.40; P < .001), equivalent to that in women with BMI <25 kg/m² (HR 1.07; P  =  .10). Weight loss after bariatric surgery was associated with reduced BC risk at 2- and 5-year washout periods as well (both P < .001).

Study details: Findings are from a population-based, multiple cohort study including 13,852 women with obesity who underwent bariatric surgery and 55,408 age- and BC screening status-matched women with no history of bariatric surgery, of which 659 women were diagnosed BC.

Disclosures: This study was supported by the Ontario Bariatric Registry, Canada, and ICES, Canada. The authors declared no conflicts of interest.

Source: Doumouras AG et al. Residual risk of breast cancer after bariatric surgery. JAMA Surg. 2023 (Apr 12). Doi: 10.1001/jamasurg.2023.0530

Key clinical point: Weight loss after bariatric surgery reduced the risk of developing breast cancer (BC) in women with prior obesity to a level equivalent to that in women with a body mass index (BMI) of <25 kg/m².

Major finding: After a 1-year washout period, women who did vs did not undergo bariatric surgery had significantly reduced BC risk (hazard ratio [HR] 1.40; P < .001), equivalent to that in women with BMI <25 kg/m² (HR 1.07; P  =  .10). Weight loss after bariatric surgery was associated with reduced BC risk at 2- and 5-year washout periods as well (both P < .001).

Study details: Findings are from a population-based, multiple cohort study including 13,852 women with obesity who underwent bariatric surgery and 55,408 age- and BC screening status-matched women with no history of bariatric surgery, of which 659 women were diagnosed BC.

Disclosures: This study was supported by the Ontario Bariatric Registry, Canada, and ICES, Canada. The authors declared no conflicts of interest.

Source: Doumouras AG et al. Residual risk of breast cancer after bariatric surgery. JAMA Surg. 2023 (Apr 12). Doi: 10.1001/jamasurg.2023.0530

Key clinical point: Weight loss after bariatric surgery reduced the risk of developing breast cancer (BC) in women with prior obesity to a level equivalent to that in women with a body mass index (BMI) of <25 kg/m².

Major finding: After a 1-year washout period, women who did vs did not undergo bariatric surgery had significantly reduced BC risk (hazard ratio [HR] 1.40; P < .001), equivalent to that in women with BMI <25 kg/m² (HR 1.07; P  =  .10). Weight loss after bariatric surgery was associated with reduced BC risk at 2- and 5-year washout periods as well (both P < .001).

Study details: Findings are from a population-based, multiple cohort study including 13,852 women with obesity who underwent bariatric surgery and 55,408 age- and BC screening status-matched women with no history of bariatric surgery, of which 659 women were diagnosed BC.

Disclosures: This study was supported by the Ontario Bariatric Registry, Canada, and ICES, Canada. The authors declared no conflicts of interest.

Source: Doumouras AG et al. Residual risk of breast cancer after bariatric surgery. JAMA Surg. 2023 (Apr 12). Doi: 10.1001/jamasurg.2023.0530