(HealthDay News) — (Tasrir) — Felipe M. Kristensson, M.D., from the Sahlgrenska Academy at the University of Gothenburg in Sweden, and colleagues examined whether bariatric surgery is associated with breast cancer incidence in women and whether the benefit is modified by baseline insulin level in the Swedish Obese Subjects study. The study included 2,867 women aged 37 to 60 years with a body mass index of 38 kg/m۲ or greater. A total of 1,420 women underwent surgery and 1,447 contemporaneous matched controls received usual obesity care.
The researchers identified 154 breast cancer events during follow-up: 66 and 88 in the surgery and usual care groups, respectively. The risk for breast cancer was reduced in the bariatric surgery group (hazard ratio, 0.68; adjusted hazard ratio, 0.72). A greater surgical treatment benefit on breast cancer risk was seen for women with baseline insulin levels above the median (15.8 µIU/L; hazard ratio, 0.48; adjusted hazard ratio, 0.55) compared with those below the median.
“The surgical treatment benefit was predominantly seen in women with hyperinsulinemia, suggesting insulin may be used as a predictor of treatment effect,” the authors write.