Cancer Patients on Insulin Had Lower Survival Rate

Cancer patients with diabetes treated with oral medications had higher survival rate than those on insulin

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Diabetes patients who also battle cancer require particularly special care. One new study shows oral anti-diabetes treatments have an advantage.

The study found that patients taking insulin for their type 2 diabetes when diagnosed with cancer were less likely to survive the first year than those without diabetes.

The researchers said that diabetes patients treated with oral anti-diabetes medication at the time of cancer diagnosis had a much greater survival rate after one year than those taking insulin.

"Discuss options for treating diabetes with your doctor."

This study was led by Kristina Ranc, of the University of Copenhagen and Steno Diabetes Center.

Ranc and colleagues looked at the records of all 426,129 cancer patients diagnosed in Denmark from 1995 through 2009.

The cancer patients were broken into four groups based on their type 2 diabetes status at the time they were diagnosed with cancer. The groups were no diabetes, diabetes without medication, diabetes with only oral medications and diabetes with insulin treatment.

The researchers linked the medical history of patients through the Danish Civil Registration System (CRS), the National Diabetes Register (NDR) and the Danish Cancer Registry (DCR).

Ranc and team found that patients who had at least a two-year history of diabetes and treated it with insulin at the time they were diagnosed with cancer were four times more likely to die within one year of their cancer diagnosis than patients without diabetes were.

The data also revealed that women under the same conditions had a slightly higher risk than men — 4.4 times greater versus 3.7 times greater.

Compared to those without diabetes, patients who had diabetes for two years and who used only oral medications saw only a 10 percent greater rate of death one year after a cancer diagnosis.

Type 2 diabetes is the most common form of diabetes and occurs when the body is unable to properly use the hormone insulin, which allows glucose (sugar) to build up in the bloodstream instead of using it as energy to fuel the body.

Insulin is a hormone produced in the pancreas that helps the body regulate blood sugar levels. In some cases, an oral medication, such as metformin, is used to help reduce blood sugar levels, but oral solutions may only work partially or not at all in some patients.

The authors of this study noted that the rate of death among patients without diabetes, as well as those who had diabetes and were on an oral diabetes medication, had a 50 percent risk of death after five years.

The authors discussed potential differences in cancer treatment between patients with and without diabetes because of diabetes-related complications such as chronic kidney disease that may contribute to an increased mortality.

"Our study provides strong support for the notion that pre-existing diabetes increases mortality among cancer patients, and that the excess mortality is larger among patients with diabetes treated with [oral medications] or, particularly, insulin," the authors wrote.

"[I]t is crucial that cancer patients with diabetes receive optimal diabetic treatment as well as any cancer-specific therapy; a therapeutic challenge requiring close collaboration between oncologists and endocrinologists," they wrote.

The authors acknowledged that this study was limited by the inability to know the patients' stage of cancer at diagnosis.

This study was published March 13 in the journal of the Diabetologia.

The authors made no disclosures.

Review Date: 
March 13, 2014
Last Updated:
March 16, 2014