HealthDay News — Having diabetes may contribute to increased mortality in patients with cancer, researchers found.
Among insulin-treated patients with a two-year history of diabetes at the time of cancer diagnosis, the mortality rate ratio was 3.7 for men (95% CI: 2.7-5.1) and 4.4 for women (95% CI: 3.1-6.5) at one year follow-up, Kristina Ranc, of the University of Copenhagen in Denmark, and colleagues reported in Diabetologia.
After nine years, the rate ratio increased to 5 for men (95% CI: 3.5 to 7.0) and 6.5 for women (95% CI:4.2-9.3).
The findings were based on data from a national registry of all patients diagnosed with cancer from 1995 to 2009. Ranc and colleagues sought to compare mortality rates among cancer patients with and without diabetes.
Mortality rates were higher for cancer patients with diabetes than for those without diabetes, as well as for those receiving oral hypoglycemic agents for diabetes, the researchers found.
For people with diabetes using only oral antidiabetic drugs (for example, metformin), the increased risk of death was much lower, at 10% for both men and women one year after cancer diagnosis having had diabetes for two years versus non-diabetics.
After 5 years, this increased risk was 50% for both men and women. For those who were not on any form of diabetes treatment, the increased risk of death was very similar to those for patients on oral antidiabetic drugs.
“In general, the highest mortality was found for insulin-treated patients, suggesting that cancer patients with more intensive diabetes treatment have a larger degree of comorbidity at the time of cancer diagnosis, and hence poorer survival,” Ranc said in a press release.