Published online Oct 6, 2020. doi: 10.12998/wjcc.v8.i19.4416
Peer-review started: May 6, 2020
First decision: June 18, 2020
Revised: June 26, 2020
Accepted: August 26, 2020
Article in press: August 26, 2020
Published online: October 6, 2020
Processing time: 144 Days and 17.4 Hours
Chronic pancreatitis is associated with pancreatic cancer (PC), although the relationship between acute pancreatitis (AP) and the risk of PC remains unclear due to inconsistent and contradictory results.
To conduct a meta-analysis of retrospective and prospective studies to explore the association between AP and PC risk.
We first searched original articles on the association of AP with PC using PubMed, Web of Science, Cochrane, and EMBASE databases. Then we calculated the combined overall effect estimates (EEs) between AP and PC risk at a 95% confidence interval (CI) deploying a random-effects model, and assessed heterogeneity using the I2 test. The combined relative risk with 95%CI was performed to examine the relationship between AP and PC. Publication bias and subgroup analyses were also conducted. Furthermore, we performed sensitivity analysis to explain this heterogeneity.
Eleven studies were eligible for inclusion standards in this meta-analysis, resulting in pooled EEs of 2.07 (95%CI: 1.36-2.78) for AP and PC risk. Additionally, five prospective cohort studies reported 103961 patients in the AP group, relative to 1442158 subjects in the control group, with a pooled relative risk of 7.81 (95%CI: 5.00-12.19). We also performed subgroup analyses using different follow-up times and type of research methods (case-control or cohort). Results from analyses of different follow-up times revealed the following pooled effect values: 1-year lag period (EEs = 23.47, 95%CI: 3.26-43.68), 2-year lag period (EEs = 9.82, 95%CI: 3.01-16.64), 5-year lag period (EEs = 2.47, 95%CI: 1.93-3.02), 10-year lag period (EEs = 1.69, 95%CI: 1.26-2.11), and > 10-year lag period (EEs = 1.17, 95%CI: 0.78-1.57). With regards to the methods, the case-control studies recorded EEs = 3.03 (95%CI: -1.02 to 7.08), whereas cohort studies had EEs = 2.09 (95%CI: 1.22-2.97) pooled effect values.
Overall, our findings indicated an association between AP and PC risk. Based on subgroup analyses, AP is unlikely to be a causal factor for PC.
Core Tip: It is well-known that acute pancreatitis (AP) might be the earliest clinical presentation of pancreatic cancer (PC). However, the relationship between AP and the risk of PC remains unclear due to inconsistent and contradictory results. In the current study, we conducted a meta-analysis of retrospective and prospective studies to explore the association between AP and PC risk. Our findings suggest that AP might not be a direct cause of PC risk, but its occurrence could be an indicator of PC. Future studies are expected to analyze the association between AP and PC risk across different follow-up times in order to improve early PC identification. Overall, more focus should be directed towards improving PC prevention approaches, of which a key element is early screening for patients at the onset of AP.