Retrospective Cohort Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Nov 14, 2017; 23(42): 7609-7617
Published online Nov 14, 2017. doi: 10.3748/wjg.v23.i42.7609
Post-colonoscopy colorectal cancer rate in the era of high-definition colonoscopy
Mineo Iwatate, Tomoyuki Kitagawa, Yasumi Katayama, Naohiko Tokutomi, Shinichi Ban, Santa Hattori, Noriaki Hasuike, Wataru Sano, Yasushi Sano, Masaya Tamano
Mineo Iwatate, Santa Hattori, Noriaki Hasuike, Wataru Sano, Yasushi Sano, Gastrointestinal Center and Institute of Minimally-Invasive Endoscopic Care, Sano Hospital, Kobe, Hyogo 655-0031, Japan
Mineo Iwatate, Tomoyuki Kitagawa, Yasumi Katayama, Naohiko Tokutomi, Masaya Tamano, Department of Gastroenterology, Dokkyo Medical University Koshigaya Hospital, Koshigaya, Saitama 343-8555, Japan
Shinichi Ban, Department of Pathology, Dokkyo Medical University Koshigaya Hospital, Koshigaya, Saitama 343-8555, Japan
Author contributions: Iwatate M, Katayama Y, Sano Y and Tamano M contributed to study concept and design; Iwatate M, Kitagawa T, Katayama Y, Tokutomi N, Ban S, Hattori S, Hasuike N, Sano W and Sano Y contributed to acquisition and analysis of data; Iwatate M drafted the manuscript; Katayama Y, Ban S, Sano Y and Tamano M critically revised the manuscript for intellectual content.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board at Sano Hospital and Dokkyo Medical University Koshigaya Hospital.
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous data that were obtained after each patient agreed to colonoscopy or surgery by written consent.
Conflict-of-interest statement: The authors have no conflicts of interest to declare in relation to this study.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Mineo Iwatate, MD, Gastrointestinal Center and Institute of Minimally-Invasive Endoscopic Care, Sano Hospital, 2-5-1 Shimizugaoka, Tarumi-ku, Kobe, Hyogo 655-0031, Japan. m.iwatate15@gmail.com
Telephone: +81-78-7851000 Fax: +81-78-7850077
Received: August 30, 2017
Peer-review started: August 31, 2017
First decision: September 20, 2017
Revised: October 2, 2017
Accepted: October 26, 2017
Article in press: October 26, 2017
Published online: November 14, 2017
Processing time: 73 Days and 12.2 Hours
Abstract
AIM

To investigate the post-colonoscopy colorectal cancer (PCCRC) rate for high-definition (HD) colonoscopy compared with that for standard-definition colonoscopy reported previously.

METHODS

Using medical records at Sano Hospital (SH) and Dokkyo Medical University Koshigaya Hospital (DMUKH), we retrospectively obtained data on consecutive patients diagnosed as having CRC between January 2010 and December 2015. The definition of PCCRC was diagnosis of CRC between 7 and 36 mo after initial high-definition colonoscopy that had detected no cancer, and patients were divided into a PCCRC group and a non-PCCRC group. The primary outcome was the rate of PCCRC for HD colonoscopy. The secondary outcomes were factors associated with PCCRC and possible reason for occurrence of early and advanced PCCRC.

RESULTS

Among 892 CRC patients, 11 were diagnosed as having PCCRC and 881 had non-PCCRC. The PCCRC rate was 1.7% (8/471) at SH and 0.7% (3/421) at DMUKH. In comparison with the non-PCCRC group, the PCCRC group had a significantly higher preponderance of smaller tumors (39 mm vs 19 mm, P = 0.002), a shallower invasion depth (T1 rate, 25.4% vs 63.6%, P = 0.01), a non-polypoid macroscopic appearance (39.0% vs 85.7%, P = 0.02) and an earlier stage (59.7% vs 90.9%, P = 0.03). Possible reasons for PCCRC were “missed or new” in 9 patients (82%), “incomplete resection” in 1 (9%), and “inadequate examination’” in 1 (9%). Among 9 “missed or new” PCCRC, the leading cause was non-polypoid shape for early PCCRC and blinded location for advanced PCCRC.

CONCLUSION

The PCCRC rate for HD colonoscopy was 0.7%-1.7%, being lower than that for standard-definition colonoscopy (1.8%-9.0%) reported previously employing the same methodology.

Keywords: Post-colonoscopy colorectal cancer; High-definition; Post-colonoscopy colorectal cancer rate; Associated factor; Possible explanation

Core tip: Technological advance from standard-definition to high-definition colonoscopy has the potential to reduce the incidence of post-colonoscopy colorectal cancer (PCCRC). We demonstrated the lower PCCRC rate for high-definition colonoscopy compared for standard-definition colonoscopy reported previously (0.7%-1.7% vs 1.8%-9.0%). Our data might help to set a benchmark for the quality of colonoscopy in Asian countries, where data on PCCRC are scarce. We firstly analyzed the possible reasons for both early and advanced “missed or new” PCCRC cases and found differences between the two groups. The leading cause was non-polypoid shape for early PCCRC and blinded location for advanced PCCRC.