Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 14, 2015; 21(6): 1857-1864
Published online Feb 14, 2015. doi: 10.3748/wjg.v21.i6.1857
Prediction of synchronous colorectal cancers by computed tomography in subjects receiving an incomplete colonoscopy: A single-center study
Er-Jun Pang, Wei-Jie Liu, Jia-Yuan Peng, Ni-Wei Chen, Jian-Hong Deng
Er-Jun Pang, Wei-Jie Liu, Jia-Yuan Peng, Department of Surgery, the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, Shanghai 200233, China
Ni-Wei Chen, Center of Endoscopy, the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, Shanghai 200233, China
Jian-Hong Deng, Department of Radiology, the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, Shanghai 200233, China
Author contributions: Pang EJ and Liu WJ contributed equally to this work; Pang EJ and Liu WJ collected the infomation of the included patients and performed the retrospective analysis; Peng JY designed the research and revised the paper for the intelectual content; Chen NW assisted in analyzing the colosocopic data; and Deng JH offered assistance in analyzing the CT findings.
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: Jia-Yuan Peng, MD, Department of Surgery, the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, 600 Yishan Road, Shanghai 200233, China. pp_no_suzhi@sina.com
Telephone: +86-21-64361349 Fax: +86-21-64368920
Received: April 11, 2014
Peer-review started: April 12, 2014
First decision: May 29, 2014
Revised: June 27, 2014
Accepted: July 29, 2014
Article in press: July 30, 2014
Published online: February 14, 2015
Processing time: 306 Days and 7.4 Hours
Abstract

AIM: To assess the value of computed tomography (CT) for diagnosis of synchronous colorectal cancers (SCRCs) involving incomplete colonoscopy.

METHODS: A total of 2123 cases of colorectal cancer (CRC) were reviewed and divided into two groups according to whether a complete or incomplete colonoscopy was performed. CT results and final histological findings were compared to calculate the sensitivity and specificity associated with CT for detection of SCRCs following complete vs incomplete colonoscopy. Factors affecting the CT detection were also analyzed.

RESULTS: Three hundred and seventy-four CRC patients underwent incomplete colonoscopy and 1749 received complete colonoscopy. Fifty-six cases of SCRCs were identified by CT, and 36 were missed. In the incomplete colonoscopy group, the sensitivity and specificity of CT were 44.8% and 93.6%, respectively. The positive and negative predictive values were 23.6% and 95.0%, respectively. In contrast, the sensitivity and specificity of CT for the complete colonoscopy group were 68.3% and 97.0%, while the positive and negative predictive values were 22.2% and 98.7%, respectively. In both groups, the mean maximum dimension of the concurrent cancers identified in the CT-negative cases was shorter than in the CT-positive cases (incomplete group: P = 0.02; complete group: P < 0.01) Topographical proximity to synchronous cancers was identified as a risk factor for missed diagnosis (P = 0.03).

CONCLUSION: CT has limited sensitivity in detecting SCRCs in patients receiving incomplete colonoscopy. Patients with risk factors and negative CT results should be closely examined and monitored.

Keywords: Synchronous colorectal cancer; Computed tomography; Colonoscopy

Core tip: This retrospective study aimed to evaluate the diagnostic accuracy of computed tomography (CT) in predicting synchronous colorectal cancers, especially in patients with incomplete colonoscopy. The study suggested that CT remains a feasible option when complete colonoscopy cannot be performed. However, the sensitivity of CT is limited due to several factors such as small tumor size, lumen conditions, and tumor location.