Circumferential margin involvement after total mesorectal excision for mid or low rectal cancer: are all R1...

Area of Science:

• Oncology
• Surgical Pathology
• Rectal Cancer Research

Background:

• The circumferential resection margin (CRM) is a critical factor in rectal cancer surgery outcomes.
• Accurate assessment of CRM is essential for predicting locoregional recurrence after total mesorectal excision (TME).

Purpose of the Study:

• To evaluate the prognostic impact of the exact CRM value on outcomes after TME for mid or low rectal cancer.
• To determine the threshold CRM value associated with significantly different recurrence rates.

Main Methods:

• Retrospective analysis of 321 patients who underwent TME between 2005 and 2013.
• Patients were categorized into four groups based on CRM: 0 mm, 0-0.4 mm, 0.4-1 mm, and >1 mm.

Main Results:

• Locoregional recurrence rates were highest in patients with CRM = 0 mm (38%) and CRM 0-0.4 mm (23%).
• Patients with CRM >0.4 mm, including those up to 1 mm, had significantly lower recurrence rates (0% for 0.4-1 mm, 10% for >1 mm).
• A CRM ≤0.4 mm was an independent predictor of impaired locoregional recurrence-free survival and disease-free survival.

Conclusions:

• A CRM of 0.4 mm or less is associated with a worse prognosis in rectal cancer surgery.
• Prognosis is similar for patients with CRM >0.4 mm (up to 1 mm) and those achieving an R0 resection.