Diabetes Raises Risk of Death by 50% with Cancer Surgery

People with diabetes who undergo cancer surgery are more likely to die in the month following their operations than those who have cancer but no diabetes, according to a study.…

The study found that patients with newly diagnosed cancer — particularly those with colorectal or oesophageal tumors — who also have Type 2 diabetes have a 50% greater risk of death following surgery.

“Diabetic patients, their oncologists, and their surgeons should be aware of the increased risk when they have cancer surgery,” said Hsin-Chieh Yeh, PhD, Johns Hopkins University School of Medicine, Baltimore, MD. “Care of diabetes before, during, and after surgery is very important. It should be part of the preoperative discussion.”

Dr. Yeh stated that, “When people are diagnosed with cancer, the focus often is exclusively on cancer, and diabetes management may be forgotten…. This research suggests the need to keep a dual focus.”

The risk picture presented by Dr. Yeh and colleagues emerged from a systematic review and meta-analysis of 15 previously published medical studies that included information about diabetes status and mortality among patients after cancer surgery. The size of the studies ranged from 70 patients to 32,621 patients, with a median of 427 patients.

“We already know that diabetes appears to increase the risk for some cancers,” said Dr. Hsin-Chieh Yeh, one of the lead researchers in the study. “This study shows that having pre-existing diabetes also increases the chance of postoperative mortality in newly diagnosed cancer patients. Although we don’t yet know the specific mechanism in cancer patients, diabetes has been shown to increase the risk of infection and cardiovascular and renal complications after surgery in the general population.”

The study, a meta-analysis, showed postoperative mortality was higher across a range of cancer surgeries and types of cancer, particularly in cancers of the colon and esophagus. The researchers concluded that further research was called for into whether improvements in perioperative diabetes care could reduce the excess risk in mortality.

Dr. Yeh noted the analysis could not say why cancer patients with diabetes are at greater risk of death after surgery. One culprit could be infection; diabetes is a well-established risk factor for infection and infection-related mortality in the general population, and any surgery can increase the risk of infections. Another cause may be cardiovascular compromise. Diabetes raises the risk of atherosclerosis and is a strong predictor of myocardial infarction and death from cardiovascular disease.

Diabetes Care, April 2010