The Diabetes-Cancer Connection: Breast Cancer

In September 2010, AICR published “The Diabetes-Cancer Connection” paper discussing the research on the link between these two diseases and how health professionals can counsel patients on lifestyle changes to lower risk of both.

Now several studies in the Journal of Clinical Oncology show how both type 2 diabetes and insulin resistance negatively impact prognosis in breast cancer patients. Those with type 2 diabetes or insulin resistance do not fare as well as breast cancer patients who did not have those conditions.

An accompanying editorial discusses two simple procedures that health care providers should do for patients with breast cancer to improve outcomes.

1.            Measure waist circumference. This simple measure may point to metabolic syndrome associated with type 2 diabetes and related risk factors.

2.            Measure HOMA index (indicator of insulin resistance).

The authors of the editorial explain that with these measures, health care providers would be able to individualize a patient’s treatment to include diet and physical activity programs that are known to improve survival for many.

The editors give a call to action to integrate care of these two diseases:

“The time has come to overcome the conventional tunnel vision that results in two diseases being treated by separate clinicians, and to move towards a comprehensive approach that ideally integrates oncologists, internists, nutritionists, and other health care professionals in an attempt to improve breast cancer prognosis in a significant proportion of patients.”

Here is an excerpt from the take home message from AICR’s InDepth paper “The Diabetes-Cancer Connection.”  For health professionals who would like to read the entire InDepth, you can log in (or if not a member, sign up) to the HPE eCommunity here.

The Take-Home

Lifestyle choices can influence risk of both diabetes and cancer. Many strategies that decrease risk of cancer also promote control of diabetes.

Weight: Excess body fat is strongly related to risk of both diabetes and cancer.

For diabetes prevention and control: if overweight, 5 to 10 percent weight loss

For cancer prevention: maintain weight within normal range from age 21; avoid weight gain and increases in waist circumference throughout adulthood

Physical activity: Lowers risk both directly and through promoting weight management benefit.

For diabetes prevention: at least 30 min/5x per week of moderate to vigorous intensity; working up to more to improve weight management

For cancer prevention: at least 30 min/day moderate intensity; as fitness improves aiming for at least 60 min/day moderate or at least 30 min/day vigorous intensity

Diet: Emphasis on minimally processed, fiber-containing plant foods supports lower risk ofdiabetes and cancer through a variety of means.

For diabetes prevention: Reduce calories and dietary fat for weight loss as appropriate; dietary fiber intake of 14 g fiber/1,000 calories, including foods containing whole grains.

For cancer prevention: a mostly plant-based diet from a variety of vegetables, fruits, whole grains and legumes, limiting energy-dense foods and “fast foods,” and avoiding sugary drinks, while limiting red meat and avoiding processed meat. Alcohol, if consumed, should be kept in moderation.