Effect of diabetes on endometrial cancer recurrence and survival

The purpose of this study was to investigate the influence of diabetes mellitus (DM) on cancer stage at diagnosis, cancer recurrence, and survival of endometrial cancer (EC) patients and the influence of the treatment of EC on glycaemic control, treatment, and complications of DM.

In this retrospective cohort study all 1644 patients with EC newly diagnosed in 2000-2008 and recorded in the population-based Eindhoven Cancer Registry (ECR) were included. In addition, from this total cohort a subcohort was selected for additional data collection and analyses, including 193 EC patients with DM and an age-matched sample of 195 EC patients without DM. Patients with FIGO stage IV as well as non-endometrioid histology were excluded.

In the total cohort EC patients with DM had a significantly higher age (69 years vs. 64 years), higher FIGO stages and more additional comorbidities compared to EC patients without DM. The 5-year overall survival rate for EC patients with DM was significantly lower than for EC patients without DM (68% vs. 84%). After adjusting for age, stage, period of diagnosis, cardiovascular disease, and treatment, this significant effect of DM on overall mortality persisted (HR 1.4, 95% CI: 1.0-1.8). Subcohort analyses showed that EC patients with DM were diagnosed more often with a higher body mass index (BMI) (34 kg/m(2) vs. 30 kg/m(2)) and EC was not significantly associated with changes in DM characteristics over time. Although the 5-year overall survival rate for EC patients with DM was significantly lower in the subcohort, for EC-specific mortality (n=388) no statistically significant effect of DM was observed after adjustment for FIGO stage (HR=1.7, 95% CI: 0.7-3.9).

EC patients with DM compared to those without had worse patient characteristics, a higher FIGO stage, similar recurrence rates and worse overall survival.