MRI-Pathology Agreement in Rectal Cancer: Real-World Data from a Prospective Rectal Cancer Registry

Area of Science:

• Oncology
• Radiology
• Gastroenterology

Background:

• Magnetic Resonance Imaging (MRI) is a standard tool for preoperative rectal cancer staging.
• Despite improvements, MRI staging concordance with final pathologic examination remains imperfect.
• Accurate staging is crucial for effective treatment planning and patient outcomes.

Purpose of the Study:

• To evaluate the agreement between MRI staging and pathologic findings in patients with mid-low rectal cancer.
• To compare MRI-pathology concordance in patients who received neoadjuvant chemoradiation therapy (nCRT) versus those who underwent upfront surgery.

Main Methods:

• Analysis of 140 patients from the AIMS Academy rectal cancer registry (January 2019 - December 2019).
• Patients included those who received nCRT (n=62) or upfront surgery (n=78).
• Comparison of T stage and N stage agreement between MRI and final pathologic examination.

Main Results:

• Overall agreement between MRI and pathology was 64.7% for T stage and 69.2% for N stage.
• T stage agreement was 62.7% for upfront surgery and 67.4% for nCRT groups (p=0.62).
• N stage agreement was 76.3% for upfront surgery and 60.0% for nCRT groups (p=0.075).

Conclusions:

• Real-world data indicates significant discrepancies between MRI staging and pathology findings in rectal cancer.
• The observed concordance rates raise concerns regarding the reliability of MRI for clinical decision-making in rectal cancer management.
• Further research is needed to improve MRI accuracy and its impact on multidisciplinary cancer board recommendations.