Acquisition of Portal Venous Circulating Tumor Cells From Patients With Pancreaticobiliary Cancers by Endoscopic Ultrasound

Abstract

BACKGROUND & AIMSTumor cells circulate in low numbers in peripheral blood; their detection is used predominantly in metastatic disease. We evaluated the feasibility and safety of sampling portal venous blood via endoscopic ultrasound (EUS) to count portal venous circulating tumor cells (CTCs), compared with paired peripheral CTCs, in patients with pancreaticobiliary cancers (PBCs).METHODSIn a single-center cohort study, we evaluated 18 patients with suspected PBCs. Under EUS guidance, a 19-gauge EUS fine needle was advanced transhepatically into the portal vein and as many as four 7.5-mL aliquots of blood were aspirated. Paired peripheral blood samples were obtained. Epithelial-derived CTCs were sorted magnetically based on expression of epithelial cell adhesion molecules; only those with a proper morphology and found to be CD45 negative and positive for cytokeratins 8, 18, and/ or 19 and 4′,6-diamidino-2-phenylindole were considered to be CTCs. For 5 samples, CTCs also were isolated by flow cytometry and based on CD45 depletion. ImageStream was used to determine the relative protein levels of P16, SMAD4, and P53. DNA was extracted from CTCs for sequencing of select KRAS codons.RESULTSThere were no complications from portal vein blood acquisition. We detected CTCs in portal vein samples from all 18 patients (100%) vs peripheral blood samples from only 4 patients (22.2%). Patients with confirmed PBCs had a mean of 118.4 ± 36.8 CTCs/7.5 mL portal vein blood, compared with a mean of 0.8 ± 0.4 CTCs/7.5 mL peripheral blood (P < .01). The 9 patients with nonmetastatic, resectable, or borderline-resectable PBCs had a mean of 83.2 CTCs/7.5 mL portal vein blood (median, 62.0 CTCs/7.5 mL portal vein blood). In a selected patient, portal vein CTCs were found to carry the same mutations as those detected in a metastatic lymph node and expressed similar levels of P16, SMAD4, and P53 proteins.CONCLUSIONSIt is feasible and safe to collect portal venous blood from patients undergoing EUS. We identified CTCs in all portal vein blood samples from patients with PBCs, but less than 25% of peripheral blood samples. Portal vein CTCs can be used for molecular characterization of PBCs and share features of metastatic tissue. This technique might be used to study the pathogenesis and progression of PBCs, as well as a diagnostic or prognostic tool to stratify risk of cancer recurrence or developing metastases.

Clinical Significance of Circulating Tumor Cells in Pancreatic Cancer

“…Compared to other types of cancer, pancreatic cancer produces fewer CTCs in peripheral blood, evidenced by the lowest number of CTCs detected per unit of blood in PC among 12 different cancer types [24]. Catenacci et al have reported that significantly more CTCs were detected in the portal vein blood than peripheral blood (118.4 ± 36.8 CTCs/7.5 mL vs. 0.8 ± 0.4 CTCs/7.5 mL, p<0.1) [25]. Correspondingly, 100% patients were detected to be CTC positive (18 pancreatic cancer patients) with portal vein blood but only 4 out of 18 CTC positive patients were seen in peripheral blood.…”

Endoscopic Ultrasound and Related Technologies for the Diagnosis and Treatment of Pancreatic Disease - Research Gaps and Opportunities

“…Pancreatic venous effluent in the portal venous system is an obvious potential source of large numbers of CTCs in PDAC, and in 2015, Catenacci et al 85 demonstrated that EUS-guided transhepatic aspiration of portal venous blood was safe and yielded relatively large numbers (~ 100 CTCs per 7.5 mL blood) of PDAC CTCs. Further, these CTCs contained the same mutations as seen in regional lymph nodes of patients who later underwent surgery.…”

The role of contrast-enhanced endoscopic ultrasound in pancreatic adenocarcinoma

“…EUS-guided sampling of the portal vein flow has been actually proposed to detect circulating tumor cells, with the aim of better selecting patients for chemotherapy or local resections. [33] Local delivery of cytotoxic or even magnetic nanoparticles, based on EUS-guided portal vein injections, has also been envisaged in advanced pancreatic adenocarcinoma with liver metastases. [34]…”