Deep Submucosal Invasion Is Not an Independent Risk Factor for Lymph Node Metastasis in T1 Colorectal Cancer:...

Area of Science:

• Oncology
• Gastroenterology
• Surgical Pathology

Background:

• Deep submucosal invasion (DSI) is a key factor for lymph node metastasis (LNM) in T1 colorectal cancer, often guiding surgical recommendations.
• However, the metastatic risk associated with DSI appears low when other histological risk factors are absent.

Purpose of the Study:

• To determine the independent risk of DSI for LNM in T1 colorectal cancer.
• To evaluate the necessity of DSI as a sole criterion for recommending oncologic surgery.

Main Methods:

• A meta-analysis was conducted, including studies that assessed LNM risk for DSI in univariable and multivariable analyses.
• Studies were eligible if they included DSI alongside other risk factors (poor differentiation, lymphovascular invasion, high-grade tumor budding) or analyzed DSI in their absence.

Main Results:

• The overall LNM rate was 11.2%, with DSI-positive cancers showing a higher rate (OR, 2.58).
• In multivariable analysis, DSI was not a significant predictor for LNM (OR, 1.73), unlike poor differentiation (OR, 2.14), high-grade tumor budding (OR, 2.83), and lymphovascular invasion (OR, 3.16).
• When analyzed as a solitary risk factor, the absolute LNM risk for DSI was 2.6%.

Conclusions:

• Deep submucosal invasion is not a strong independent predictor of lymph node metastasis.
• DSI should be reconsidered as a sole indicator for oncologic surgery in T1 colorectal cancer.
• This finding supports tailoring management strategies, potentially favoring local excision in suitable cases.