Systematic Reviews
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 7, 2022; 28(21): 2383-2395
Published online Jun 7, 2022. doi: 10.3748/wjg.v28.i21.2383
Endoscopic ultrasound-guided injectable therapy for pancreatic cancer: A systematic review
Jyotroop Kaur, Veeravich Jaruvongvanich, Vinay Chandrasekhara
Jyotroop Kaur, Veeravich Jaruvongvanich, Vinay Chandrasekhara, Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, United States
Author contributions: Kaur J and Chandrasekhara V conceived and designed the study and critically reviewed the manuscript; Kaur J and Chandrasekhara V conducted the literature search, screened for eligibility, and drafted the manuscript; Kaur J and Jaruvongvanich V collected, analyzed, and interpreted the data; all authors reviewed the literature and revised the manuscript, read and approved the final manuscript.
Conflict-of-interest statement: There are no conflicts of interest to report.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
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: Vinay Chandrasekhara, FASGE, MD, Associate Professor, Attending Doctor, Department of Gastroenterology and Hepatology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, United States. chandrasekhara.vinay@mayo.edu
Received: December 10, 2021
Peer-review started: December 10, 2021
First decision: January 8, 2022
Revised: January 18, 2022
Accepted: April 22, 2022
Article in press: April 22, 2022
Published online: June 7, 2022
Abstract
BACKGROUND

Given the low survival rate in pancreatic cancer, new therapeutic techniques have been explored, especially for unresectable or borderline resectable disease. Endoscopic ultrasound (EUS) provides real-time imaging and minimally invasive access for local and targeted injection of anti-tumor agents directly into the pancreatic tumor. Limited studies have been reported using this technique for the treatment of pancreatic ductal adenocarcinoma (PDAC).

AIM

To evaluate the progress made with EUS-guided injectable therapies in the treatment of PDAC.

METHODS

All original articles published in English until July 15, 2021, were retrieved via a library-assisted literature search from Ovid Evidence-Based Medicine Reviews and Scopus databases. Reference lists were reviewed to identify additional relevant articles. Prospective clinical studies evaluating the use of EUS-guided injectable therapies in PDAC were included. Studies primarily directed at non-EUS injectable therapies and other malignancies were excluded. Retrieved manuscripts were reviewed descriptively with on critical appraisal of published studies based on their methods and outcome measures such as safety, feasibility, and effectiveness in terms of tumor response and survival. Heterogeneity in data outcomes and therapeutic techniques limited the ability to perform comparative statistical analysis.

RESULTS

A total of thirteen articles (503 patients) were found eligible for inclusion. The EUS-injectable therapies used were heterogeneous among the studies consisting of immunotherapy (n = 5) in 59 patients, chemotherapy (n = 1) in 36 patients, and viral and other biological therapies (n = 7) in 408 patients. Eleven of the studies reviewed were single armed while two were double armed with one randomized trial and one non-randomized comparative study. Overall, the included studies demonstrated EUS-guided injectable therapies to be safe and feasible with different agents as monotherapy or in conjunction with other modalities. Promising results were also observed regarding their efficacy and survival parameters in patients with PDAC.

CONCLUSION

EUS-guided injectable therapies, including immunotherapy, chemotherapy, and viral or other biological therapies have shown minimal adverse events and potential efficacy in the treatment of PDAC. Comparative studies, including controlled trials, are required to confirm these results in order to offer novel EUS-based treatment options for patients with PDAC.

Keywords: Pancreatic ductal adenocarcinoma, Endoscopic ultrasound-guided fine-needle injection, Local injectable therapy, Immunotherapy, Chemotherapy, Oncolytic viral therapy

Core Tip: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy. Resistance to systemic therapies may be attributable to the dense stromal matrix in the pancreatic tumor mass. Endoscopic ultrasound-guided fine-needle injection (EUS-FNI) is a novel technique to deliver various anti-tumor agents locally in real-time and may overcome this limitation. This review examines the EUS-FNI therapies used to treat PDAC.