Histological Risk Factors for Lymph Node Metastasis in pT1 Colorectal Cancer: Does Submucosal Invasion Depth Really...

Area of Science:

• Gastroenterology
• Surgical Oncology
• Pathology

Background:

• Endoscopic resection of T1 colorectal cancer (CRC) requires careful assessment for lymph node metastasis (LNM).
• Deep submucosal invasion (DSI) is often considered an indicator for additional surgery, but its predictive value for LNM needs clarification.

Purpose of the Study:

• To identify reliable risk factors for LNM in patients with pT1 CRC.
• To evaluate the specific impact of DSI on LNM in this patient cohort.

Main Methods:

• Analysis of clinicopathological characteristics in pT1 CRC patients who underwent lymph node dissection.
• Utilized Chi-square tests and multivariate logistic regression to assess LNM risk factors.
• Measured submucosal invasion depth (SID) using four methods and three cut-off values.

Main Results:

• LNM was observed in 11.7% (28/239) of patients.
• Independent risk factors for LNM included high histological grade, lymphovascular invasion (LVI), intermediate to high tumor budding (Bd 2/3), and cancer gland rupture (CGR).
• Submucosal invasion depth (SID), width (WSI), and area (ASI) were not significant predictors of LNM; LNM rates increased significantly with the number of identified histological risk factors.

Conclusions:

• Subjective measurements like SID, WSI, and ASI are not reliable or practical risk factors for LNM in pT1 CRC.
• Histological factors such as grade, LVI, tumor budding, and CGR are statistically significant and more straightforward to assess for LNM risk.
• Clinical decisions for pT1 CRC should prioritize these histological indicators over subjective invasion measurements.