15123 Background: Though pancreatic cancer ranks eighth among all major forms of cancer related deaths, it accounts for only 3% of all cancers worldwide. Diabetes mellitus type 2 and pancreatic cancer are known to be associated but this relationship decreases inversely with an increasing duration of diabetes. The aim of the present study is to assess whether new onset type 2 diabetes is a risk factor for pancreatic cancer or it results as an outcome of pancreatic cancer. Methods: We conducted a meta-analysis of all available studies to examine this association. Using PUBMED, EMBASE & MEDLINE we searched the literature for studies from 1980 to present. All published studies with quantitative estimates and standard errors, or confidence limits, of the association between type 2 diabetes and pancreatic cancer were included. Studies having patients with an un-defined period of diabetes or diabetes for greater than 5 years before the development of pancreatic cancer were excluded. 14 case control and 11 cohort trials with information on 5807 individuals with pancreatic cancer met the above criteria. Each study was independently reviewed by 2 reviewers. Results: The pooled odds ratio for case control studies for patients with diabetes and pancreatic cancer was 1.98 (95% CI - 1.58–2.42) while that for cohort studies was 1.88 (95% CI - 1.72–2.16). The combined odds ratio was 1.92 (95% CI - 1.62 - 2.38). However in patients who developed pancreatic cancer with in 2 years of diagnosis of diabetes the odd’s ratio was significantly higher (OR- 3.2, 95% CI - 2.24- 4.02). Conclusions: On the basis of above data pancreatic cancer is more likely to occur in new onset diabetes mellitus type 2 than the general population. However, the evidence above is insufficient to conclude that diabetes mellitus is indeed a risk factor for pancreatic cancer. Since the relative risk of developing pancreatic cancer was higher in patients with new onset type 2 diabetes in the first two years, it further supports the hypothesis that the development of diabetes may be a manifestation of early but yet undiagnosed pancreatic cancer. Large population based studies are needed to truly determine this relationship. No significant financial relationships to disclose.
Is diabetes mellitus a risk factor for pancreatic cancer?
