Published online Sep 14, 2017. doi: 10.3748/wjg.v23.i34.6315
Peer-review started: November 4, 2016
First decision: January 19, 2017
Revised: March 21, 2017
Accepted: May 19, 2017
Article in press: May 19, 2017
Published online: September 14, 2017
Processing time: 315 Days and 8.3 Hours
To detect the existence of isolated cancer cells in the mesentery of colorectum (named as Metastasis V), and investigate its clinical significance in colorectal cancer (CRC) patients.
Sixty-three CRC patients who received radical excision between January 2012 and September 2015 were included. All the patients underwent laparoscopy-assisted radical colorectomy or proctectomy [with complete mesocolic excision (CME) or total mesorectal excision (TME)] with R0 dissections at the Department of Gastrointestinal Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. The location and size of the primary lesions were recorded immediately after the tumor was removed, with the surrounding mesenterium completely separated along the intestinal wall. Each dissected mesentery sample was analyzed for hematoxylin-eosin staining and immunohistochemistry using cytokeratin 19 antibody. Image Pro Plus Software 6.0 (Media Cybernetics, CA, United States) was used to semi-quantitatively measure the concentration of the cytokeratin 19 immunohistochemistry. The correlation between metastasis found in mesentery and clinicopathological characteristics was examined. The prognosis of patients was also evaluated by preoperative serum CEA level.
Metastasis V was detected in 14 of 63 (22.2%) CRC patients who underwent laparoscopy-assisted radical colorectomy or proctectomy (with CME or TME) with R0 dissection in our hospital between January 2012 and September 2015. There was no significant difference in age, gender, tumor size, and tumor location in patients with Metastasis V (P > 0.05). Metastasis V was more likely to occur in poorly differentiated tumor (5/11; 45.5%) than moderately (8/46; 17.4%) and well- differentiated one (1/6; 16.7%). The Metastasis V in N2 stage (9/14; 64.3%) was more frequent that in the N0 stage (3/35; 8.6%) or N1 stages (2/14; 14.3%). In addition, Metastasis V was positively related to the tumor invasive depth (T1:0/1, 0%; T2:1/12, 8.3%; T3:7/39, 17.9%; T4:6/11, 54.5%). Furthermore, preoperative serum CEA level in Metastasis V-positive patients was significantly higher than in Metastasis V-negative patients (4.27 ng/mL vs 3.00 ng/mL).
Metastasis V might be associated with a poor prognosis of CRC patients.
Core tip: Local-regional recurrence of colorectal cancer (CRC) is common in patients who received R0 resection. Our previous study proposed a novel type of metastasis designated as “Metastasis V” in gastric cancer. Metastasis V is defined as the appearance of cancer cells in the mesentery in broad sense, and may be a risk factor for the poor prognosis after radical surgery. In this study, Metastasis V was also detected in the mesentery of colorectum, and it might be associated with the poor prognosis of CRC patients.