Ligand-targeted polymerase chain reaction for the detection of folate receptor-positive circulating tumour cells as a potential diagnostic biomarker for pancreatic cancer.

Abstract

ObjectivesTo detect folate receptor (FR)‐positive circulating tumour cells (FR+ CTCs) by using ligand‐targeted polymerase chain reaction (LT‐PCR) in periampullary cancer patients and to investigate the diagnostic value of FR+ CTCs in distinguishing pancreatic cancer (PC) from benign pancreatic disease.Materials and MethodsCTCs were enriched from 3 mL of peripheral blood and portal vein blood by immunomagnetic depletion of leucocytes and were then detected by LT‐PCR. The diagnostic performance of FR+ CTCs in PC was investigated by receiver‐operating characteristic curve analysis.ResultsIn total, 57 consecutive patients, including 46 patients with PC, five patients with non‐pancreatic periampullary cancer (non‐PC) and six patients with benign pancreatic diseases, were enrolled. FR+ CTC levels were significantly higher in patients with malignant diseases (PC and non‐PC) than in patients with benign pancreatic diseases (P < .01). There was no notable difference in CTC levels between patients with PC and those with non‐PC (P > .05). The combination of FR+ CTCs with carbohydrate antigen 19‐9 (CA19‐9) had better diagnostic efficiency than each of these two markers alone, with high sensitivity (97.8%) and specificity (83.3%).ConclusionsLT‐PCR is feasible and reliable for detecting FR+ CTCs in patients with periampullary cancer. FR+ CTCs, especially when used in combination with CA19‐9, have potential as a biomarker for the diagnosis of PC.