Clinicopathological Significance of CDKN2A Promoter Hypermethylation Frequency with Pancreatic Cancer

The prognosis of pancreatic cancer patients is very poor, with a 5-year survival of less than 6%. Previous studies demonstrated that the loss of function of CDKN2A is mainly caused by the hypermethylation of CDKN2A gene promoter; however, whether or not it is associated with the incidence of pancreatic cancer still remains unclear. In this study, we systematically reviewed the association between CDKN2A promoter methylation and pancreatic cancer using meta-analysis methods. The pooled data were analyzed by Review Manager 5.2. Fourteen studies eligible studies, including 418 pancreatic cancer, 155 pancreatic intraepithelial neoplasia (PanINs) and 45 chronic pancreatitis (CP) patients were analyzed. We observed that the frequency of CDKN2A methylation was significantly higher in pancreatic cancer patients than in normal healthy controls, the pooled OR = 17.19, 95% CI = 8.72-33.86, P < 0.00001. The frequency of CDKN2A methylation was also significantly higher in PanINs patients than that in normal individual controls, OR = 12.35, 95% CI = 1.70-89.89, P = 0.01. In addition, CDKN2A methylation was associated with worse survival in pancreatic cancer, HR = 4.46, 95% CI = 1.37-14.53, P = 0.01. The results strongly suggest that CDKN2A methylation is correlated with an increased risk of pancreatic cancer. CDKN2A methylation plays a critical role in pancreatic carcinogenesis and may serve as a prognostic marker.