Droplet digital PCR quantification of miR-1290 as a circulating biomarker for pancreatic cancer

Droplet digital PCR was used to validate miR-1290 as circulating biomarker for pancreatic cancer (PC). The diagnostic performance of miR-1290 was evaluate in 167 PC patients and 267 healthy subjects at clinical risk of developing the disease (HS). MiR-1290 plasma levels were compared to CA 19-9 determinations, and the combination of the two biomarkers was also taken into account. Plasma levels of miR-1290 were higher in PC patients compared to HS (p = 2.55 x 10(-16)). A similar trend was observed for CA 19-9 determinations (p = 1.03 x 10(-47)). ROC curve analysis revealed that miR-1290 in combination with CA 19-9 was effective for discriminating between PC patients and HS (AUC = 0.956, 95% CI = 0.933-0.979) than the two biomarkers tested alone (miR-1290: AUC = 0.734, 0.678-0.789; CA 19-9: AUC = 0.914, 0.877-0.951). The discriminating ability was higher when only PC patients with low or slightly increased CA 19-9 levels were compared with HS. MiR-1290 concentrations were not able to differentiate between PC patients with single or multiple risk factors for developing PC. Our data suggest that the absolute quantification of circulating miR-1290 levels does not allow to select patients at clinical risk of PC for entry into a surveillance program, and underline the methodological challenges still existing in utilizing circulating miRNAs as new promising biomarkers for PC.