Association of Poor Differentiation or Positive Vertical Margin with Residual Disease in Patients with Subsequent Colectomy after Complete Macroscopic Endoscopic Resection of Early Colorectal Cancer.

Sang Won Lee,Seong Woo Jeon,Hyun Seok Lee,Sun Jin,Ki Ju Kim

doi:10.1155/2017/7129626

Abstract

In the presence of unfavorable pathologic results after endoscopic resection of colorectal cancer, colectomy is routinely performed. We determined the risk factors for residual diseases in patients with colectomy after complete macroscopic endoscopic resection of early colorectal cancer. We identified consecutive patients who underwent endoscopic resection of early colorectal cancer and subsequently underwent colectomy, from January 2011 to December 2014. Clinicopathologic risk factors related to the residual disease were analyzed. In total, 148 patients underwent endoscopic resection and subsequent colectomy. Residual disease on colectomy was noted in 16 (10.9%) patients. The rates of poorly differentiated/mucinous histology (p = 0.028) and of positive or unknown vertical resection margin (p = 0.047) were higher in patients with residual disease than in those without. In multivariate analysis, a poorly differentiated/mucinous histology and positive or unknown vertical resection margin were significantly associated with residual disease (odds ratio = 7.508 and 2.048, p = 0.015 and 0.049, resp.). After complete macroscopic endoscopic resection of early colorectal cancer, there is a greater need for additional colectomy in cases with a positive or unknown vertical resection margin or a poorly differentiated/mucinous histology, because of their higher risk of residual cancer and lymph node metastasis.

Highlights

The increased availability and widespread use of colonoscopy have allowed the early detection of colorectal polyps [1,2,3]
Concerning the associated risk, most authors acknowledge that a positive endoscopic resection margin, poor tumor differentiation, lymphovascular invasion, and deep submucosal invasion are associated with adverse outcomes [4, 5, 7,8,9,10]
All patients had 1 or more of the following risk factors for residual disease: (i) the lesion had a poorly differentiated/mucinous histology; (ii) the vertical or lateral endoscopic resection margin was positive, or the status of the margin was unknown; (iii) lymphovascular invasion was found in the endoscopic resection specimen; or (iv) the submucosal invasion depth was >1000 μm

Summary

Introduction

The increased availability and widespread use of colonoscopy have allowed the early detection of colorectal polyps [1,2,3]. The proportion of polyps that contain invasive cancer is not high; 0.2–8.3% of them are malignant polyps, which invade through the muscularis mucosa and can metastasize to regional lymph nodes. After endoscopic resection, colectomy may be necessary to ensure the complete removal of residual tumors in the colorectal wall and of local lymph node metastasis [4,5,6]. Patients with any of these high-risk factors typically undergo radical colectomy with lymph node dissection after endoscopic resection. Most such patients have no residual disease in their surgical specimen, despite these risk factors. The proportion of patients with residual tumor, lymph node metastasis, or recurrent tumor during follow-up is 10–13% [4]

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