Being very overweight is an established breast cancer risk factor, as is having metabolic syndrome or type 2 diabetes. Researchers are refining their understanding of the relationships between these factors, as well as the potential influences of changes in body weight on treatment outcomes. Below we summarize the results of some of the studies concerning body weight and type 2 diabetes that are scheduled to be presented in early June at the American Society of Clinical Oncology annual meeting in Chicago:
  • Diabetes and obesity each are associated with a significant reduction in overall survival from early-stage breast cancer, as well as a borderline significant decrease in recurrence-free survival, after adjusting for diabetes status, body mass index (BMI), age, stage, grade, and hormone receptor status.
  • Obesity predicts worse outcomes in HER2-positive breast cancer patients and reduces the effectiveness of Herceptin treatment.
  • A pilot study of weight loss intervention in high risk women found that a six-month weight loss goal of 5% of baseline weight was achievable and resulted in improvement in multiple tissue-based breast cancer risk biomarkers.
  • Type 2 diabetes is significantly associated with poorer overall survival among women with early stage breast cancer.