A new study suggests that cancer patients who have previously been diagnosed with diabetes and are being treated with insulin have a higher risk of early death. In fact, the research shows that diabetic cancer patients taking insulin are four times more likely to die prematurely.
The study, led by Dr. Kristina Ranc from the University of Copenhagen, was published in the journal Diabetologia. Her and a team of researchers set out to determine a possible link between diabetic cancer patients and early death. The observation study used data for cancer patients in Denmark who has been diagnosed between 1995 and 2009. They broke down the data into four distinct categories of people, including one with cancer but no diabetes, one with diabetes without medical treatment, one with diabetes who were treated with oral medication and one with diabetes who were being treated with insulin.
Of the 426,129 people studies, 42,205 had diabetes prior to their cancer diagnosis. The data came from the Danish Civil Registration System, the National Diabetes Register and the Danish Cancer Registry. Each person had a unique identification number.
The researchers used death as their primary interest, then looked for those with diabetes. They compared the data of the four district groups. They discovered that diabetic cancer patients using insulin were four times more likely to die earlier than those who were not treated with insulin. The age of patients being treated with oral diabetic medication was 73. The age was only 70, however, for cancer patients who were being treated with insulin.
Study co-author Marit Eika Jørgensen explained to Medical News that because cancer is not diagnosed early on, diabetic cancer patients are not given “aggressive cancer therapy, and cancer surgery mortality is higher with insulin treated diabetes.”
They found that patients who were then diagnosed with diabetes did not have a worse prognosis. In fact, it was being diabetic and taking insulin before having cancer that correlated with an early death. The study concluded that the more intensive the treatment of the diabetes, the higher risk for early death in cancer patients.
“The results suggest that mortality of cancer patients with pre-existing diabetes is higher relative to non-diabetic patients for all cancers combined and for most individual cancer sites,” Dr. Ranc Said.
Ranc and her colleagues state there are several potential explanations for the early death of diabetic cancer patients. They suggest it could be the co-morbidity factor, hidden cancer symptoms that are diagnosed too late or drug interactions that affect cancer treatment.
Since the study is based on national data, no selection bias was involved, however, the researchers did not have access to the stage of cancer or cancer treatments that the subjects received. Having this additional data could change the conclusion, as chemotherapy and other cancer treatments may play a role in the early death of diabetic cancer patients.
The takeaway from the study is that diabetic cancer patients should consider options that are optimal for both health issues. The study cannot create a link between cancer and diabetes, as far as one causing the other, but it does point out the need for additional research on the topic.
By Tracy Rose