Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 14, 2015; 21(10): 2967-2972
Published online Mar 14, 2015. doi: 10.3748/wjg.v21.i10.2967
Indeterminate pulmonary nodules in colorectal cancer
Eun-Joo Jung, Su-Ran Kim, Chun-Geun Ryu, Jin Hee Paik, Jeong Geun Yi, Dae-Yong Hwang
Eun-Joo Jung, Su-Ran Kim, Chun-Geun Ryu, Jin Hee Paik, Dae-Yong Hwang, Department of Surgery, Colorectal Cancer Center, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-729, South Korea
Jeong Geun Yi, Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-729, South Korea
Author contributions: Jung EJ wrote the paper and analyzed the data; Kim SR, Ryu CG and Paik JH filled up the data; Yi JG reviewed the radiologic imagings; Hwang DY designed the research.
Supported by Konkuk University.
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: Dae-Yong Hwang, MD, PhD, Professor of Surgery, Department of Surgery, Colorectal Cancer Center, Konkuk University Medical Center, Konkuk University School of Medicine, 120-1 Neungdong-ro (Hwayang-dong), Gwangjin-gu, Seoul 143-729, South Korea. hwangcrc@kuh.ac.kr
Telephone: +82-2-20305111 Fax: +82-2-20305112
Received: August 25, 2014
Peer-review started: August 26, 2014
First decision: September 15, 2014
Revised: October 11, 2014
Accepted: November 30, 2014
Article in press: December 1, 2014
Published online: March 14, 2015
Abstract

AIM: To investigate the clinicopathologic parameters of pulmonary metastasis in colorectal cancer (CRC) patients after lung operation of indeterminate pulmonary nodules (IPNs).

METHODS: From a prospective database of CRC patients, 40 cases that underwent lung operation between November 2008 and December 2012 for suspicious metastatic pulmonary nodules on chest computed tomography (CT) were enrolled. The decision to perform a lung operation was made if the patient met the following criteria: (1) completely resected or resectable primary CRC; (2) completely resectable IPNs; (3) controlled or controllable extrapulmonary metastasis; and (4) adequate general condition and pulmonary function to tolerate pulmonary operation. Lung operation was performed by a thoracic surgeon without CT-guided biopsy for pathologic confirmation.

RESULTS: A total of 40 cases of lung resection was performed in 29 patients. Five patients underwent repeated lung resection. The final pathology result showed metastasis from the CRC in 30 cases (75%) and benign pathology in 10 cases (25%). The primary tumor site was the rectum in 26/30 (86.6%) cases with pulmonary metastasis, but only 3/10 (30%) cases in the benign group had a primary rectal cancer (P = 0.001). Positron emission tomography (PET)-CT was performed for 22/30 (73.4%) patients in the lung metastasis group and for 6/10 (60.0%) patients in the benign group. PET-CT revealed hot uptake of 18fluorine 2-fluoro-2-deoxy-D-glucose with all IPNs in both groups. The group with pulmonary metastasis had a higher incidence of primary rectal cancer (P = 0.001), a more advanced tumor stage (P = 0.011), and more frequent lymphatic invasion of tumor cells (P = 0.005). Six cases with previous liver metastasectomy were present in the lung metastasis group. Serum carcinoembryonic antigen levels before lung operation were not elevated in any of the patients.

CONCLUSION: The stage and location of the primary tumor and tumor cell infiltration of lymphatics provide useful indicators for deciding on lung resection of IPNs in CRC.

Keywords: Colorectal neoplasm, Lung neoplasm, Indeterminate pulmonary nodule, Lung metastasis, Chest computed tomography

Core tip: This study demonstrated that 25% of indeterminate pulmonary nodules are benign lesions, even though metastasis was suspected after chest computed tomography or positron emission tomography before surgical pulmonary resection. More importantly, we demonstrated that useful indicators for deciding on lung resection of indeterminate pulmonary nodules in colorectal cancer were the primary tumor stage, location of the primary tumor, and tumor cell infiltration of lymphatics.