Maximizing Weight Loss After Roux-en-Y Gastric Bypass May Decrease Risk of Incident Organ Cancer

Recent studies have suggested that metabolic surgery reduces cancer risk. This study aims to determine if incident cancer is associated with the extent of weight loss after Roux-en-Y gastric bypass (RYGB).

Patients at a large tertiary bariatric surgery center were retrospectively reviewed to identify patients with no history of cancer at the time of RYGB. Diagnoses in the electronic health record, a tumor registry, and chart review were used to identify postoperative incident solid organ cancer. The overall incidence of organ cancer was estimated using Kaplan-Meier analysis. The percent total body weight loss (%TWL) in the 48 months after surgery but prior to cancer was compared between those that developed organ cancer versus those that did not using repeated measures linear regression.

The 2943 patients had a mean age of 45.6 years (SD = 11.1), 81 % were female, and a mean baseline body mass index (BMI) of 47.2 kg/m² (SD = 7.9). Median follow-up after surgery was 3.8 years (range = [<1, 12]). Incident organ cancer developed and was verified in 54 of the 2943 patients (1.8 %). Kaplan-Meier estimates for cancer at 3, 5, and 10 years postsurgery were 1.3, 2.5, and 4.2 %. After adjusting for age, BMI, sex, diabetes, hypertension, and dyslipidemia, patients that developed organ cancer achieved less weight loss (-1.5 % TWL, 95 % CI = [-2.9 %, -0.1 %], p = 0.034).

Greater weight loss after metabolic surgery may be associated with lower organ cancer risk.