Impact of diabetes mellitus on the survival of pancreatic cancer: a meta-analysis

BACKGROUND: Diabetes mellitus (DM) is a risk factor for pancreatic cancer (PC), but its prognostic value in PC is still unclear. To elucidate this issue, we systematically reviewed the evidence concerning the association between diabetes status and PC. METHODS: Medline and EMBASE databases were searched to identify the eligible studies. Overall and subgroup analyses were performed to detect the discrepancy of prognosis according to diabetes status. Hazard ratios (HRs) with 95% CI were used to estimate the effect size. RESULTS: Eighteen studies including 16,181 patients with sample size ranging from 113 to 4,658 were pooled in this meta-analysis. Results showed that patients with DM had worse survival (HR 1.19, 95% CI: 1.07–1.32). In view of the impact of diabetes duration and tumor stage on the outcomes, we classified the studies into different groups. The results indicated that DM was associated with survival in both long-standing diabetes (HR 1.26, 95% CI: 1.14–1.40) and recent-onset diabetes (HR 1.29, 95% CI: 1.09–1.51). Data regarding localized disease (HR 1.57, 95% CI: 1.00–2.46) and nonlocalized (locally advanced and metastatic) disease (HR 1.42, 95% CI: 1.16–1.73) verified that the prognostic value was independent of tumor stage. CONCLUSION: Our results suggested that patients with DM were associated with worse survival than those without DM. Diabetes may be a predictive factor of survival in patients with PC. Surveillance of diabetes status and antidiabetes medication administration after the diagnosis of PC is of clinical importance.