Elevated Hemoglobin A1c Levels Are Associated with Worse Survival in Advanced Pancreatic Cancer Patients with Diabetes

BACKGROUND/AIMS: Pre-existing diabetes mellitus (DM) has been identified as an adverse prognostic variable associated with increased mortality in various cancers. Although DM and hyperglycemia are considered risk factors for pancreatic cancer (PC), antidiabetic treatments for patients with advanced PC have been overlooked. This study aimed to evaluate the impact of hemoglobin A1c (HbA1c) levels on PC survival. METHODS: We retrospectively reviewed the medical records of first-diagnosed patients with advanced PC who were admitted to Konkuk University Medical Center from 2005 to 2011. RESULTS: A total of 127 patients were enrolled, and there were 111 deaths (87.4%) within the 7-year observational period. The most common etiology was disease progression (n=108). DM before PC diagnosis was observed in 65 patients (51.1%), including 28 patients with new-onset DM. The overall median survival times in patients with and without DM were 198 and 263 days, respectively (p=0.091). Survival time according to HbA1c was significantly different between the <7.0% and ≥7.0% groups (362 and 144 days, respectively; p=0.038). In the HbA1c ≥7.0% group, the median overall survival time was 273 days for the metformin group and 145 days for the nonmetformin oral agent group; however, there was no significant difference between the two groups (p=0.058). CONCLUSIONS: A high HbA1c level may be associated with worse survival in patients with advanced PC with DM. Antidiabetic treatment, metformin in particular, was associated with an improved outcome.