Format

Send to

Choose Destination
Cancer Epidemiol Biomarkers Prev. 2019 Nov 4. pii: cebp.0781.2019. doi: 10.1158/1055-9965.EPI-19-0781. [Epub ahead of print]

Metformin Use and Pancreatic Cancer Survival among non-Hispanic White and African American US Veterans with Diabetes Mellitus.

Author information

1
Department of Surgery, Division of Public Health Sciences, Washington University in St. Louis School of Medicine a.toriola@wustl.edu.
2
Hematology, Washington University in St. Louis School of Medicine.
3
Research Service, St. Louis Veterans Affairs Medical Center.
4
Department of Surgery, Division of Public Health Sciences, Washington University in St. Louis.
5
Division of Public Health Sciences, Department of Surgery, Washington University in St. Louis.

Abstract

BACKGROUND:

The effect of metformin use on survival among pancreatic ductal adenocarcinoma (PDAC) patients is controversial. Further, there are no data on African American patients. To address these, we analyzed data from the United States Veterans Health Administration (VHA).

METHODS:

A population-based retrospective cohort study evaluating overall survival among 3,811 PDAC patients with pre-existing diabetes mellitus (DM), diagnosed with PDAC within the VHA between 1998 and 2013. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) using multivariable adjusted time-varying Cox proportional hazards regression to control for immortal time bias and confounders.

RESULTS:

Metformin use was not associated with overall survival in the complete analyses: HR=1.05 (95%CI 0.92-1.14, p-value=0.28). However, among patients who were metformin naïve at the time of PDAC diagnosis (N=1,158), metformin use was associated with improved overall survival in non-Hispanic white: HR=0.78 (95%CI 0.61-0.99, p-value=0.04), but not African American patients: HR=1.20 (95%CI 0.75-1.93, p-value=0.45). The survival benefit among non-Hispanic whites was limited to patients with metastatic disease: HR=0.67 (95%CI 0.44-1.01, p-value=0.06). Among African American patients with metastatic disease, HR= 1.30 (95%CI 0.77-2.53, p-value=0.28). There was suggestion of heterogeneity by race in patients with metastatic disease (p-heterogeneity=0.05).

CONCLUSIONS:

We observed no associations between metformin use and survival in PDAC patients, but there appears to be a survival benefit among non-Hispanic white patients who were metformin naïve at the time of PDAC diagnosis.

IMPACT:

If confirmed in other studies, our findings suggest that metformin as an adjunctive treatment for PDAC may not improve survival among African American patients.

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center