Bariatric surgery decreases the risk of uterine malignancy

Objective

To describe the risk of uterine malignancy among women who have had weight loss surgery.

Methods

We performed a retrospective cohort study among inpatient admissions of women 18 years, or older, registered in the University HealthSystem Consortium (UHC) dataset. The rate of uterine malignancy per hospital admission was calculated. Rates were compared according to whether diagnoses at the time of discharge included history of bariatric surgery, and further, according to whether there was a diagnosis of obesity.

Results

In admissions of patients who did not have a history of prior bariatric surgery, the rate of uterine malignancy was 599/100,000 (95% CI 590 to 610). Among obese women who had not previously undergone bariatric operations, the rate was 1409/100,000 (95% CI 1380 to 1440). Of women admitted who had a history of bariatric surgery, the rate of uterine malignancy was 408/100,000 (95% CI 370 to 450). The relative risk of uterine malignancy in all admissions for women who had prior bariatric surgery, compared to obese women who had not had bariatric surgery, was 0.29 (95% CI 0.26–0.32). Among women who had bariatric surgery and were not currently obese, the relative risk of uterine malignancy was 0.19 (95% CI 0.17–0.22) compared to obese women who had not undergone bariatric surgery.

Conclusion

A history of bariatric surgery is associated with a 71% reduced risk for uterine malignancy overall, and an 81% reduced risk if normal weight is maintained after surgery. This finding suggests that obesity may be a modifiable risk factor related to development of endometrial cancer.