Background and Objective: Current epidemiological studies report conflicting
results for the effect of statin or metformin on pancreatic cancer overall survival. This literature
review and meta-analysis summarize the studies reporting an association between
statin or metformin use and overall survival of pancreatic cancer patients.
Methods: We systematically searched for studies about the association between statin or
metformin use and pancreatic cancer overall survival in electronic databases (PubMed, ISI
Web of Science, MEDLINE, Cochrane, Scopus, Google Scholar). A meta-analysis based
on hazard ratios (HRs) and 95% confidence intervals (CIs) was performed using random
effect models. Heterogeneity between the studies was examined using I2 statistics, and sensitivity
analyses were conducted to assess the robustness of the findings.
Results: Of 116 statin-related articles identified, 6 retrospective cohort studies representing
12,057 patients were included. There was significant heterogeneity between studies. Statin
use was associated with improved survival among pancreatic cancer patients (meta-HR =
0.75; 95% CI: 0.59, 0.90; P < 0.001). Of 311 metformin-related articles, 8 retrospective cohort
studies and 2 randomized clinical trials, representing 3,042 patients were identified.
Metformin use was associated with better overall survival among pancreatic cancer patients
(meta-HR = 0.79; 95% CI: 0.70, 0.92, P < 0.001), and significant heterogeneity was observed
Conclusion: Our findings suggest that the improved survival time of pancreatic cancer patients
are associated with statin or metformin use. Due to the multiple sources of heterogeneity
of the original studies, these findings should be considered cautiously, and confirmed
with larger prospective individual-level studies.