(HealthDay News) — For patients with obesity undergoing bariatric surgery, losing at least 20 to 35 percent of total body weight is associated with a more than 50 percent reduction in the risk for cancer, according to a study presented at the annual meeting of the American Society for Metabolic and Bariatric Surgery and The Obesity Society (ObesityWeek), held from Nov. 3 to 7 in Las Vegas.
Andrea Stroud, M.D., from Oregon Health & Science University in Portland, and colleagues examined the correlation for surgical weight loss and changes in serum biomarkers with incident cancer in a cohort of 2,353 patients undergoing bariatric surgery.
The researchers found that 82 patients reported a new cancer diagnosis during 8,759 person-years of follow-up (936 per 100,000 person-years; 95 percent confidence interval, 749 to 1,156); 55 cancers were thought to be linked with obesity. The risk for cancer was lower for achieving a body mass index (BMI) <30 kg/m² (hazard ratio, 0.59; 95 percent confidence interval, 0.34 to 1.00) and for losing at least 20 to 34.9 percent of total body weight (versus <20 percent: hazard ratio, 0.44; 95 percent confidence interval, 0.25 to 0.76). An increased risk for incident cancer was seen with baseline BMI ≥50 kg/m² versus BMI <40 kg/m² (hazard ratio, 1.40; 95 percent confidence interval, 0.68 to 2.86). The investigators also observed a decreased cancer risk associated with postoperative levels of glucose, proinsulin, insulin, and leptin.
“Our data suggests that there is a weight-loss threshold, that if achieved, significantly reduces risk of cancer in postbariatric surgery patients,” Stroud said in a statement.