Table 3.

Associations of metformin use with risk of all-cause mortality in patients with PDAC with preexisting diabetes mellitus among patients who were metformin naïve at the time of PDAC diagnosis, using the time-varying Cox model.

Metformin useDeaths/totalMedian survival (95% CI)HR (95% CI)aPPheterogeneity
 Nonuserb988/1,0193.7 (3.3–4.0)Ref.
 User107/13919.6 (12.0–31.0)0.77 (0.61–0.98)0.03
Non-Hispanic whites
 Nonuserb746/7703.8 (3.3–4.3)Ref.
 User85/11225.7 (14.9–34.4)0.78 (0.61–0.99)0.04
African Americans
 Nonuserb242/2493.4 (2.8–4.0)Ref.
 User22/279.2 (3.4–16.6)1.20 (0.75–1.93)0.45
  • aAdjusted for age (continuous), gender (male or female), BMI, year of diagnosis (2004 and prior, 2005–2008, 2009, and after), surgery (yes or no), smoke status (never, current, or previous), and stage (resectable, locally advanced, metastatic, or unknown).

  • bMetformin nonusers comprised individuals who were not taking just metformin. They could be taking other medications for diabetes.