Does Omitting Additional Surgery After Local Resection Affect Oncological Outcomes in Patients with High-Risk pT1...

Area of Science:

• Gastroenterology and Surgical Oncology
• Colorectal Cancer Research
• Oncologic Pathology

Background:

• Colorectal cancer (CRC) is a major cause of cancer mortality in Spain.
• Endoscopic polypectomy (EP) is standard for pT1 adenocarcinomas, but determining the need for further surgery is challenging.
• Intramural residual tumor (IRT) and lymph node metastasis (LNM) incidence varies in high-risk pT1 cases.

Purpose of the Study:

• To identify histological factors predicting residual disease after EP for pT1 CRC.
• To evaluate strategies for reducing unnecessary completion surgeries in high-risk pT1 CRC patients.
• To analyze outcomes based on risk stratification and management approach.

Main Methods:

• Retrospective analysis of 276 patients with pT1 CRC treated with complete EP (2013-2021).
• High-risk pT1 criteria included positive margins, deep invasion (≥2mm), lymphovascular invasion, high-grade budding, unfavorable histology, or indeterminate features.
• Patients were stratified into low-risk (LR), high-risk endoscopic management (HR-E), and high-risk surgical management (HR-S) groups with long-term follow-up.

Main Results:

• Residual disease was found in 18.7% of surgical specimens.
• Positive margins correlated with IRT (p=0.01), and unfavorable histology with LNM (p=0.000).
• Recurrence rates were similar between HR-E and HR-S for single-risk-factor patients; no CRC-specific deaths occurred in the HR-E group.

Conclusions:

• Positive resection margins and unfavorable histology are key predictors of IRT and LNM in pT1 CRC.
• Selected high-risk patients, especially those with comorbidities or a single risk factor, may safely defer completion surgery with vigilant follow-up.
• This approach can reduce surgical morbidity without compromising survival outcomes in pT1 CRC management.