Non-Operative Management of Rectal Cancer

Patient Selection Criteria

• The American Society of Clinical Oncology recommends that non-operative management (NOM) should only be considered for patients meeting strict criteria for clinical complete response after neoadjuvant therapy, including digital rectal examination, rectoscopy findings, MRI criteria, and endoscopic biopsy 1, 2
• Patients must have no palpable tumor material present on digital rectal examination, no residual tumor material and no erythematous ulcer on rectoscopy, and substantial tumor downsizing with no observable residual tumor material on MRI 1

Optimal Neoadjuvant Regimen to Achieve cCR

• The National Comprehensive Cancer Network recommends total neoadjuvant therapy (TNT) with long-course chemoradiotherapy followed by consolidation chemotherapy to maximize the likelihood of achieving clinical complete response suitable for NOM 1, 3
• The specific TNT regimen should include long-course chemoradiation (50 Gy in 1.8 Gy fractions with concurrent 5-FU-based chemotherapy) followed by consolidation chemotherapy (FOLFOX or similar regimen) 1, 4

Special Population: MSI-H/dMMR Tumors

• The American Society of Clinical Oncology recommends immunotherapy as the preferred treatment for patients with microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) locally advanced rectal cancer, which may result in exceptionally high rates of complete response 1, 3

Patient Counseling and Shared Decision-Making

• The European Society for Medical Oncology recommends discussing improved functional outcomes with NOM, including preserved anorectal function and quality of life, as well as surgical risk factors and likelihood of identifying complete response 1, 2
• Patients should be informed about the intensive surveillance requirements necessary with NOM approach and the reduced risk of permanent ostomy if NOM is successful 1, 2

Surveillance Protocol for NOM

• The American Society of Clinical Oncology recommends regular digital rectal examinations, serial endoscopic assessments, interval MRI imaging with diffusion-weighted sequences, and CEA monitoring for patients selecting NOM 1, 2, 5

Current Evidence Level

• The National Comprehensive Cancer Network states that while retrospective and prospective cohort studies demonstrate high rates of local control and disease-free survival with NOM comparable to surgery-based therapy, total mesorectal excision after neoadjuvant therapy remains the standard of care for locally advanced rectal cancer 2