What is the significance of the circumferential margin in locally advanced rectal cancer after neoadjuvant chemoradiotherapy?

Ann Surg Oncol. 2013 Apr;20(4):1179-84. doi: 10.1245/s10434-012-2722-7. Epub 2013 Jan 18.


Background: The circumferential resection margin (CRM) is highly prognostic for local recurrence in rectal cancer surgery without neoadjuvant treatment. However, its significance in the setting of long-course neoadjuvant chemoradiotherapy (nCRT) is not well defined.

Methods: Review of a single institution's prospectively maintained database from 1998 to 2007 identified 563 patients with locally advanced rectal cancer (T3/T4 and/or N1) receiving nCRT, followed after 6 weeks by total mesorectal excision (TME). Kaplan-Meier, Cox regression, and competing risk analysis were performed.

Results: The authors noted that 75 % of all patients had stage III disease as determined by endorectal ultrasound (ERUS) and/or magnetic resonance imaging (MRI). With median follow-up of 39 months after resection, local and distant relapse were noted in 12 (2.1 %) and 98 (17.4 %) patients, respectively. On competing risk analysis, the optimal cutoff point of CRM was 1 mm for local recurrence and 2 mm for distant metastasis. Factors independently associated with local recurrence included CRM ≤1 mm, and high-grade tumor (p = 0.012 and 0.007, respectively). CRM ≤2 mm, as well as pathological, nodal, and overall tumor stage are also significant independent risk factors for distant metastasis (p = 0.025, 0.010, and <0.001, respectively).

Conclusion: In this dataset of locally advanced rectal cancer treated with nCRT followed by TME, CRM ≤1 mm is an independent risk factor for local recurrence and is considered a positive margin. CRM ≤2 mm was associated with distant recurrence, independent of pathological tumor and nodal stage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / mortality
  • Adenocarcinoma / pathology
  • Adenocarcinoma / therapy*
  • Adolescent
  • Adult
  • Aged
  • Chemoradiotherapy*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Neoadjuvant Therapy*
  • Neoplasm Metastasis
  • Neoplasm Recurrence, Local / diagnosis*
  • Neoplasm Recurrence, Local / mortality
  • Neoplasm Staging
  • Prognosis
  • Prospective Studies
  • Rectal Neoplasms / mortality
  • Rectal Neoplasms / pathology
  • Rectal Neoplasms / therapy*
  • Risk Factors
  • Survival Rate
  • Young Adult