Obesity and Diabetes Could Affect Cancer Treatment

Breast cancer treatment hampered by obesity and diabetes

(RxWiki News) Diabetes and obesity are problematic on their own, but could they also affect how the body responds to treatments for other conditions, like cancer? New studies suggest this is the case.

Two new studies explored obesity and diabetes in European breast cancer patients undergoing chemotherapy.

The researchers found that breast cancer patients with either obesity or diabetes had a lower chance of living five years without their cancer spreading.

"Find ways to stay active during the day, like opting for the stairs when possible."

The two new studies were both led by Caterina Fontanella, MD, of the German Breast Group in Neu-Isenburg, Germany. The first study focused on how body mass index (BMI), a ratio of weight to height, might affect breast cancer treatment outcomes in patients receiving chemotherapy as a first treatment option before any surgery for their cancer. The second study considered how type 2 diabetes might affect outcomes for these patients.

In the first study, Dr. Fontanella and team looked at a total of 10,727 breast cancer patients, gathered from two European studies of breast cancer patients — the German Breast Group (GBG) and the European Organization for Research and Treatment of Cancer (EORTC). Based on their BMIs, patients were divided into three groups representing normal weight BMIs (or underweight), overweight BMIs and obese BMIs.

The researchers found that overall, participants with an increased BMI had a decreased chance of surviving for five years without the cancer spreading or without the cancer recurring later.

Among the GBG participants, 79.4 percent of patients with normal BMIs survived five years without the cancer spreading, while the same was true for 78.4 percent of patients with overweight BMIs and 73.7 percent of patients with obese BMIs.

Among the EORTC participants, 73 percent of patients with normal BMIs survived five years without the cancer recurring, while the same was true for 64.3 percent of patients with overweight BMIs and 62.2 percent of patients with obese BMIs.

It is important to note that when looking at patients with a type of condition called HER2-positive breast cancer, these same findings did not hold true and BMI did not seem to have an effect on these patients' cancer outcomes.

For the second study, Dr. Fontanella and team looked at 4,065 patients from the and GeparQuattro and GeparQuinto trials.

The researchers found that 112 (2.8 percent) of these breast cancer patients were diagnosed with type 2 diabetes.

The patients with diabetes tended to be older and have higher BMIs than their peers without diabetes. The breast cancer patients with diabetes had an average age of 61 and an average BMI of 30.3 — a BMI considered obese. In comparison, the patients without diabetes had an average age of 49 and an average BMI of 24.9 — considered normal weight.

The researchers found that breast cancer patients with diabetes were more likely to be diagnosed with more advanced tumors and advanced-stage cancer.

The group was also less likely to survive for five years without the cancer spreading — 68.6 percent of the diabetes patients met this mark, while the same was true of 78.2 percent of the patients without diabetes.

These studies were presented March 21 at the 9th European Breast Cancer Conference in Glasgow, Scotland. It is important to note that studies presented at conferences are considered preliminary until published in a peer-reviewed journal.

No conflicts of interest were reported in either study.

Review Date: 
March 20, 2014