High Rate of Positive Circumferential Resection Margins Following Rectal Cancer Surgery

Abstract

Objective To identify predictors of positive circumferential resection margin following rectal cancer resection in the United States. Background Positive circumferential resection margin is associated with a high rate of local recurrence and poor morbidity and mortality for rectal cancer patients. Prior study has shown poor compliance with national rectal cancer guidelines, but whether this finding is reflected in patient outcomes has yet to be shown. Methods Patients who underwent resection for stage I-III rectal cancer were identified from the 2010-2011 National Cancer Database. The primary outcome was a positive circumferential resection margin. The relationship between patient, hospital, tumor, and treatment-related characteristics was analyzed using bivariate and multivariate analysis. Findings A positive circumferential resection margin was noted in 2,859 (17.2%) of the 16,619 patients included. Facility location, clinical T and N stage, histologic type, tumor size, tumor grade, lymphovascular invasion, perineural invasion, type of operation, and operative approach were significant predictors of positive circumferential resection margin on multivariable analysis. Total proctectomy had nearly a 30% increased risk of positive margin compared to partial proctectomy (OR 1.293, 95%CI 1.185-1.411) and a laparoscopic approach had nearly 22% less risk of a positive circumferential resection margin compared to an open approach (OR 0.882, 95%CI 0.790-0.985). Interpretation Despite advances in surgical technique and multimodality therapy, rates of positive circumferential resection margin remain high in the United States. Several tumor and treatment characteristics were identified as independent risk factors, and advances in rectal cancer care are necessary to approach the outcomes seen in other countries.

Clinicopathological factors associated with positive circumferential margins in rectal cancers

“…Our series also demonstrates the aggressive pathological phenotypes of rectal cancers with positive CRM encountered in our population. Factors associated with positive CRM including APR as mode of surgery, worsening tumour grade, increased T‐stage, vascular and perineural invasion have previously been established . Patients undergoing APR are more likely to have locally advanced and distal tumours increasing the complexity of resection .…”

“…Despite pre‐operative local staging with magnetic resonance imaging (MRI), the widespread uptake of the total mesorectal excision technique and use of neoadjuvant radiation patients continue to remain at risk of positive CRM. Examples in recent studies range from 7.8% to 21% in centres located in Australia, New Zealand, USA, UK and Canada . Several factors have been associated with CRM status including technical performance, social demographics, hospital case load, neoadjuvant therapies, procedure performed (low anterior resection versus abdominoperineal resection (APR)) and tumour biology .…”

Lymph node yield is an independent predictor of survival in rectal cancer regardless of receipt of neoadjuvant therapy

“…The analysis was limited to cases of adenocarcinoma, mucinous adenocarcinoma and signet ring cell carcinoma on histology as these accounted for the largest proportion. Mucinous adenocarcinoma and signet ring cell carcinoma were considered separately due to the association of these histologies with more aggressive disease than typical adenocarcinoma as was done in previous NCDB studies 16 17. The sample was further limited to those who had undergone a documented proctectomy.…”

Oncological safety of laparoscopic versus open colorectal cancer surgery in obesity: a systematic review and meta‐analysis

“…The rate of CRM (6.8%) and R1 (6.9%) resections were consistent with current literature for NOB patients. Large national studies have shown CRM rates as low as 7.7% to higher rates of 21.1% . The lower rate seen in OB patients can be due to a number of factors, such as tumour size, type of operation, the degree of lymphovascular and perineural invasion, as shown in the Consortium for Optimizing the Treatment of Rectal Cancer (OSTRiCh) study .…”