Meta-analysis of the studies dedicated to the predictive significance of circulating tumor DNA in pancreatic cancer

Abstract

The method of liquid biopsy allows detection of circulating tumor DNA (ctDNA) in patient blood, but the clinical significance of this approach in pancreatic cancer is still unclear. In this regard, we have carried out a meta-analysis of the studies dedicated to the predictive significance of ctDNA in pancreatic cancer.
 Materials and methods.We carried out the search for the articles and abstracts in PubMed, ASCO and ESMO databases published before February 2020, containing data about the connection between ctDNA and the prognosis of pancreatic cancer. The exclusion criteria were the studies including 10 or less participating patients, absence of the data about the relative risk of mortality and/or progression, and the 95% confidence interval. The meta-analysis was carried out by using the Review Manager software (RevMan), Version 5.3.
 Results.There were no significant systematic errors associated with the publications. The presence of ctDNA in patient blood showed poor overall survival of patients (odds ratio OR 2.21, 95% confidence interval CI 1.35-3.33,p=0.001) regardless of the prevalence of the disease. In case of the resectable process, the detection of ctDNA in patient blood both before and after surgery was a factor of worse progression-free survival (OR 2.32, 95% CI 1.543.5,p0.001 and OR 3.06, 95% CI 1.635.76,р=0.0005 and overall survival (OR2.01, 95% CI 1.123.63,р=0,02 and OR 3.39, 95% CI 2.125.44,р0.00001, respectively).
 Conclusions.The detection of ctDNA in the bloodstream in pancreatic cancer patients is a factor of poor prognosis in both localized and advanced cancer. It is very important to make further prospective studies to develop the optimal protocol for detecting ctDNA in patient bloodstream.