What is the Prognostic Significance of Positive Lymph Nodes at the Circumferential Resection Margin in Rectal Cancer: A Systematic Review
In brief
Node-positive margins double 5-year survival compared with direct tumor extension
In a systematic review of 5,303 rectal cancer patients, those whose circumferential resection margin was positive because of metastatic lymph nodes (162 patients) had 5-year overall survival around 50%, versus 20-30% when positivity was due to direct tumor spread. Local recurrence was also lower (5-12% vs 22-52%). The finding suggests the mechanism of margin involvement may influence prognosis, but larger prospective studies are needed before it changes practice.
- Journal
- Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract (Q1)
- Published
- 27 August 2026
- Study design
- Systematic review of cohort studies
- Evidence level
- Level 2, Moderate (CEBM 2a)
- Authors
- Ellen Groundwater, Christopher Ray, Harikrishnan Nair, David G Watt
- PMID
- 42660345
- DOI
- 10.1016/j.gassur.2026.102569
Why clinicians should know about it
- Picked for Pathology and Forensic Medicine (paper of the day, 30 August 2026): Prognostic significance of node‑positive circumferential resection margin in rectal cancer
Abstract
INTRODUCTION: Circumferential resection margin (CRM) positivity is an established predictor of local recurrence and survival in rectal cancer. The prognostic impact of CRM positivity specifically attributable to tumour within lymph nodes at the CRM (node-positive CRM) is unclear. We performed a systematic review to determine whether CRM positivity caused by lymph node metastases confers similar oncological risk to CRM positivity from direct tumour extension. METHODS: A systematic search of MEDLINE, EMBASE, CINAHL and Cochrane Library was conducted in March 2026 for studies reporting outcomes for patients with CRM positivity specifically due to lymph node involvement. Search strings combined terms for "rectal cancer", "circumferential resection margin" and "lymph node". Two reviewers screened records and extracted data. Study quality was assessed with the Newcastle-Ottawa Scale. Outcomes of interest were overall survival, disease-free survival, local recurrence and distant recurrence. Due to heterogenous outcome reporting and small numbers no meta-analysis was performed and a structured narrative synthesis was conducted. RESULTS: From 138 records screened, 5 studies (published between 2002-2024) including 5,303 patients met inclusion criteria; 162 patients were CRM-positive due to lymph nodes. Across all studies, node-positive CRM patients generally demonstrated more favourable outcomes than patients with CRM positivity due to direct tumour extension: 5-year overall survival ranged 49-51% for node-positive CRM versus 20-29% for tumour-extension CRM. Local recurrence in node-positive CRM ranged from 5-12% versus 22-52% for tumour-extension CRM. CONCLUSION: CRM positivity due solely to metastatic lymph nodes may be associated with more favourable oncological outcomes than CRM positivity resulting from direct tumour extension. Prospective multicentre studies with standardised pathological classification and reporting are required to determine whether the mechanism of CRM involvement represents an independent prognostic factor before these findings can inform clinical practice.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.