Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 14, 2022; 28(30): 4019-4043
Published online Aug 14, 2022. doi: 10.3748/wjg.v28.i30.4019
Role of one-step nucleic acid amplification in colorectal cancer lymph node metastases detection
Francesco Crafa, Serafino Vanella, Onofrio A Catalano, Kelsey L Pomykala, Mario Baiamonte
Francesco Crafa, Serafino Vanella, Mario Baiamonte, Division of General and Surgical Oncology, St. Giuseppe Moscati Hospital, Center of National Excellence and High Specialty, Avellino 83100, Italy
Onofrio A Catalano, Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, United States
Kelsey L Pomykala, Department of Nuclear Medicine, Department of Radiological Sciences, David Geffen School of Medicine at University of California, Los Angeles, University Hospital Essen, University of Duisburg-Essen, Essen 45141, Germany
Author contributions: Crafa F wrote and edited the manuscript and collected the clinical data; Vanella S reviewed the discussion section of the manuscript; Baiamonte M, Catalano OA and Pomykala KL revised the manuscript and provided recommendations for the clinical diagnosis paragraph.
Conflict-of-interest statement: Dr Crafa has nothing to disclose.
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:
Corresponding author: Francesco Crafa, MD, Director, Division of General and Surgical Oncology, St. Giuseppe Moscati Hospital, Center of National Excellence and High Specialty, C/da Amoretta, Avellino 83100, Italy.
Received: February 26, 2022
Peer-review started: February 26, 2022
First decision: May 9, 2022
Revised: June 3, 2022
Accepted: July 20, 2022
Article in press: July 20, 2022
Published online: August 14, 2022

Current histopathological staging procedures in colorectal cancer (CRC) depend on midline division of the lymph nodes (LNs) with one section of hematoxylin and eosin staining. Cancer cells outside this transection line may be missed, which could lead to understaging of Union for International Cancer Control Stage II high-risk patients. The one-step nucleic acid amplification (OSNA) assay has emerged as a rapid molecular diagnostic tool for LN metastases detection. It is a molecular technique that can analyze the entire LN tissue using a reverse-transcriptase loop-mediated isothermal amplification reaction to detect tumor-specific cytokeratin 19 mRNA. Our findings suggest that the OSNA assay has a high diagnostic accuracy in detecting metastatic LNs in CRC and a high negative predictive value. OSNA is a standardized, observer-independent technique, which may lead to more accurate staging. It has been suggested that in stage II CRC, the upstaging can reach 25% and these patients can access postoperative adjuvant chemotherapy. Moreover, intraoperative OSNA sentinel node evaluation may allow early CRC to be treated with organ-preserving surgery, while in more advanced-stage disease, a tailored lymphadenectomy can be performed considering the presence of aberrant lymphatic drainage and skip metastases.

Keywords: Colorectal malignancies, One-step nucleic acid amplification, Diagnostic accuracy, Negative predictive value, Upstaging, Organ-sparing surgery, Tailored lymphadenectomy

Core Tip: Our findings suggest that the one-step nucleic acid amplification (OSNA) assay has high diagnostic accuracy and negative predictive value in detecting metastatic lymph nodes in colorectal cancer (CRC). The short turnaround time renders OSNA an attractive intra-operative method. OSNA results in upstaging in about 25% of stage II CRC cases. Moreover, organ-sparing surgery in early CRC and tailored lymphadenectomy, in more advanced cases, can be performed.