The impact of diabetes on survival in women with ovarian cancer.

OBJECTIVE: Diabetes is increasingly common among cancer patients and plausible biologic mechanisms exist by which diabetes may influence cancer prognosis. We aimed to investigate the impact of diabetes on ovarian cancer outcomes.

METHODS: We assessed the outcomes of 570 non-diabetic and 72 diabetic patients with epithelial ovarian, fallopian tube, and primary peritoneal cancer over a ten-year period. All inpatient and outpatient records were reviewed. The primary end points were overall and disease-free survival.

RESULTS: Of the 642 cases, 11.2% had type II diabetes. Diabetics were more likely to be older, had a higher BMI (33.4 vs. 27.8), and had more comorbid conditions. Diabetics were less likely to have been surgically staged as compared to non-diabetics (p=0.04) although stage, grade, and likelihood of optimal cytoreduction were similar between groups. Over a period of 10 years, with an average of 44 months of follow-up, the median overall survival for diabetics was 1503 days. The median overall survival for non-diabetics was 2464 days (log rank test, p=0.02). In a Cox proportional hazards multivariable model, diabetes remained a significant predictor of overall survival (HR=2.04, p<0.01).

CONCLUSIONS: Diabetics with ovarian cancer demonstrate strikingly poorer survival. The underlying reason for this is yet unknown and deserves further attention. Differences in care, competing risks of death, and changes within the tumor biology are plausible mechanisms for the observed difference in survival.