Prognostic importance of circumferential resection margin in the era of evolving surgical and multidisciplinary treatment of rectal cancer: A systematic review and meta-analysis

Abstract

Background: Circumferential resection margin is considered an important prognostic parameter after rectal cancer surgery, but its impact might have changed because of improved surgical quality and tailored multimodality treatment. The aim of this systematic review was to determine the prognostic importance of circumferential resection margin involvement based on the most recent literature. Methods: A systematic literature search of MEDLINE, Embase, and the Cochrane Library was performed for studies published between January 2006 and May 2019. Studies were included if 3-or 5-year oncological outcomes were reported depending on circumferential resection margin status. Outcome parameters were local recurrence, overall survival, disease-free survival, and distant metastasis rate. The Newcastle Ottawa Scale and Jadad score were used for quality assessment of the studies. Meta-analysis was performed using a random effects model and reported as a pooled odds ratio or hazard ratio with 95% confidence interval. Results: Seventy-five studies were included, comprising a total of 85,048 rectal cancer patients. Significant associations between circumferential resection margin involvement and all long-term outcome parameters were uniformly found, with varying odds ratios and hazard ratios depending on circumferential resection margin definition (<1 mm, 1 mm, otherwise), neoadjuvant treatment, study period, and geographical origin of the studies. Conclusion: Circumferential resection margin involvement has remained an independent, poor prognostic factor for local recurrence and survival in most recent literature, indicating that circumferential resection margin status can still be used as a short-term surrogate endpoint.

Pathological Features and Prognostication in Colorectal Cancer

“…Criterion used to define a positive CRM remains controversial [ 252 , 253 , 254 ]. The most commonly-used definition of CRM positivity is tumour ≤1 mm from the tumour-free margin [ 252 ].…”

“…Criterion used to define a positive CRM remains controversial [ 252 , 253 , 254 ]. The most commonly-used definition of CRM positivity is tumour ≤1 mm from the tumour-free margin [ 252 ]. CRM positivity occurs in 7.3% to 25% of rectal cancers and 5.3% to 20.5% of colon cancers.…”

“…It is associated with advanced stage, aggressive tumour grade, infiltrating tumour border, and lymphovascular and perineural invasion [ 253 , 255 ]. In rectal cancer, CRM positivity is a strong predictor of recurrence and reduced survival, independent of TNM staging [ 252 , 256 , 257 , 258 , 259 ]. Positive CRM is associated with increased risk of local recurrence (HR 4.67 95% CI 2.51–4.15), distal metastasis (HR 2.95), and reduced OS (HR 3.21) and DFS (HR 3.63) [ 252 ].…”

“…In rectal cancer, CRM positivity is a strong predictor of recurrence and reduced survival, independent of TNM staging [ 252 , 256 , 257 , 258 , 259 ]. Positive CRM is associated with increased risk of local recurrence (HR 4.67 95% CI 2.51–4.15), distal metastasis (HR 2.95), and reduced OS (HR 3.21) and DFS (HR 3.63) [ 252 ]. The prognostic significance of CRM is stronger in patients undergoing neo-adjuvant radiotherapy prior to surgery compared with surgery alone, likely because tumours with limited response to radiotherapy are biologically unfavourable [ 256 ].…”

Quantifying displacement of urogenital organs after abdominoperineal resection for rectal cancer

“…The external validity of the study might also be influenced by other population characteristics such as age, although a mean of 64 years has commonly been found in European rectal cancer studies [11].…”