Association between oral contraceptive use and pancreatic cancer risk:A systematic review and meta-analysis

摘要

BACKGROUND Studies on the association of oral contraceptive(OC)use and pancreatic cancer showed inconsistent findings.AIM To evaluate the relationship between OC use and pancreatic cancer risk.METHODS A literature search for observational studies(case-control and cohort studies)was conducted up to December 2020.A meta-analysis was performed by calculating pooled relative risks(RRs)and 95%confidence intervals(CIs).Heterogeneity was assessed using Cochran’s chi-square test and I2 statistic.Subgroup analyses were performed by study design,source of controls in case-control studies,number of cases of pancreatic cancers,study quality according to Newcastle-Ottawa Scale score,geographical region and menopausal status.All analyses were performed using Review Manager 5.3(RevMan 5.3).RESULTS A total of 21 studies(10 case-control studies and 11 cohort studies)were finally included in the present meta-analysis,comprising 7700 cases of pancreatic cancer in total.A significant association was observed between the ever use of OC and pancreatic cancer risk in the overall analysis(RR=0.85;95%CI=0.73-0.98;P=0.03).Duration of OC use(<1 year,<5 years,5-10 years,>10 years)was not significantly associated with the risk of pancreatic cancer.Subgroup analyses revealed a statistically significant subgroup difference for the geographic region in which the study was conducted(Europe vs Americas vs Asia;P=0.07).Subgroup analyses showed a statistically significant decrease in pancreatic cancer risk and OC use in high-quality studies,studies conducted in Europe,and in postmenopausal women.CONCLUSION Despite the suggested protective effects of OC use in this meta-analysis,further epidemiological studies are warranted to fully elucidate the association between the use of OC and pancreatic cancer risk.