Lead investigator Dr. Joseph Sparano of the Albert Einstein College of Medicine at the Montefiore Medical Center in New York and therapeutics co-chair of the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network Breast Committee and colleagues analyzed data from 6,885 women with stage 1 to stage 3 breast cancer.
The women were free of significant co-morbidities; the rate of obesity defined by body mass indexes of 25 percent to 37 percent.
The study, published online ahead of the print edition of the journal Cancer, found even overweight women who were not obese had a higher risk of breast cancer recurring, despite receiving the best cancer treatment.
"We've had a very tumor-centric view of treating cancer and haven't paid much attention to how characteristics of the patient influence prognosis," Sparano said in a statement. "We found a pretty striking relationship between obesity and recurrence of a common breast cancer subtype, which we think may eventually lead to testing new strategies to prevent recurrence."