Comparison of clinical usefulness of serum Ca125 and CA19-9 in pancreatic adenocarcinoma diagnosis: meta-analysis and systematic review of literature

Introduction: Pancreatic adenocarcinoma remains one of the most lethal cancers. The only recommended biomarker CA19-9 proves to be not accurate enough to establish a certain diagnosis. Therefore, a determination of usefulness of other biomarkers is essential. Our aim was to compare the specificity and sensitivity of Ca125 and CA19-9 by means of meta-analysis. The systematic review of combined tests (CA19-9 + Ca125) was also performed. Methods: We conducted a systematic search of Medline (via PubMed) and Ovid. After screening of abstracts and the assessment of full-texts, nine studies (number of patients, n = 1599) were included. Hierarchical summary receiver under operator curve (hsROC) model was applied to estimate the diagnostic accuracy. Results: CA19-9 sensitivity and specificity were 0.748 (95%CI 0.676-0.809) and 0.782 (95%CI 0.716-0.836), respectively. These values were estimated on 0.593 (95%CI 0.489-0.69) and 0.754 (95%CI 0.817-0.668) for Ca125. Regarding the heterogeneity of studies, a strong threshold effect for Ca125 and moderate one for CA19-9 were found. Conclusions: Our meta-analysis did not prove the superiority of Ca125. It should be nevertheless noted that the sparsity of studies precludes accurate analysis of various factors' influence. The review of proposed combined tests shows that CA19-9 + Ca125 models are generally characterized by higher sensitivity.