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World J Gastrointest Oncol. Apr 15, 2023; 15(4): 632-643
Published online Apr 15, 2023. doi: 10.4251/wjgo.v15.i4.632
Clinical implications and perspectives of portal venous circulating tumor cells in pancreatic cancer
Sung Woo Ko, Seung Bae Yoon
Sung Woo Ko, Seung Bae Yoon, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, South Korea
Seung Bae Yoon, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, Seoul 03312, South Korea
Author contributions: Ko SW and Yoon SB contributed equally to the conception, design, and literature search; Ko SW drafted the manuscript and prepared the tables; Yoon SB modified and revised the manuscript.
Supported by the National Research Foundation of Korea, No. NRF-2021 R1F1A1062255.
Conflict-of-interest statement: All authors report no relevant conflicts of interest for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Seung Bae Yoon, MD, PhD, Associate Professor, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, 1021, Tongil Ro, Eunpyeong-gu, Seoul 03312, South Korea. sbyoon@catholic.ac.kr
Received: December 24, 2022
Peer-review started: December 24, 2022
First decision: January 30, 2023
Revised: February 10, 2023
Accepted: March 15, 2023
Article in press: March 15, 2023
Published online: April 15, 2023
Abstract

Despite recent improvements in the diagnosis and treatment of pancreatic cancer (PC), clinical outcomes remain dismal. Moreover, there are no effective prognostic or predictive biomarkers or options beyond carbohydrate antigen 19-9 for personalized and precise treatment. Circulating tumor cells (CTCs), as a member of the liquid biopsy family, could be a promising biomarker; however, the rarity of CTCs in peripheral venous blood limits their clinical use. Because the first venous drainage of PC is portal circulation, the portal vein can be a more suitable location for the detection of CTCs. Endoscopic ultrasound-guided portal venous sampling of CTCs is both feasible and safe. Several studies have suggested that the detection rate and number of CTCs may be higher in the portal blood than in the peripheral blood. CTC counts in the portal blood are highly associated with hepatic metastasis, recurrence after surgery, and survival. The phenotypic and genotypic properties measured in the captured portal CTCs can help us to understand tumor heterogeneity and predict the prognosis of PC. Small sample sizes and heterogeneous CTC detection methods limit the studies to date. Therefore, a large number of prospective studies are needed to corroborate portal CTCs as a valid biomarker in PC.

Keywords: Circulating tumor cell, Pancreatic cancer, Portal vein, Outcomes, Prognosis, Survival

Core Tip: Circulating tumor cells (CTCs) are emerging minimally invasive biomarkers for evaluating tumor characteristics; however, limited CTCs are detected in the peripheral blood. Portal venous blood, which does not undergo hepatic filtration, can theoretically harbor a large number of CTCs and can be safely assessed using endoscopic ultrasound. The efficacy of CTCs in portal venous blood have shown encouraging results (i.e., higher detection rate and better prediction of prognosis). Here, we provide an overview of CTCs in portal venous blood in the clinical context and future perspectives to enhance the role of portal CTCs as a valid biomarker in pancreatic cancer.