The majority of patients with pT2 colon cancer have no lymph node metastasis (LNM). Knowledge of risk factors for LNM in pT2 colon cancer could identify patients at low risk and thereby potential candidates for local tumor excision. The aim was to identify risk factors for LNM in pT2 colon cancer and describe a subgroup of low-risk patients.
Retrospective cohort study on patients with pT2 colon cancer from a nationwide Danish colorectal cancer database. Age, tumor size, location, histological type, mismatch repair protein status, venous, lymphatic and perineural invasion were included as potential risk factors in multivariate analysis. Primary outcome was LNM.
We identified 1306 patients with pT2 colon cancer, LNM was present in 244 (19%). Demographic data were comparable in patients with and without LNM, and 864 patients who had complete histological data were included for multivariate analysis. Lymphatic (OR = 3.60, 95% CI 2.14-5.9), venous (OR = 1.70, 95% CI 1.03-2.74) and perineural (OR = 4.61, 95% CI 1.60-13.5) invasion were independent risk factors for LNM. Patients with deficient mismatch repair protein tumors had a decreased risk of LNM (OR = 0.55, 95% CI 0.31-0.95). Patients with clinical stage I colon cancer and without risk factors had 10.5% (47/443) risk of LNM. For patients with tumors with deficient mismatch repair protein status and no risk factors, the risk was 7.9%.
Lymphatic, venous and perineural invasion are significant risk factors and we identified a subgroup of patients with a low risk of LNM.

This article is protected by copyright. All rights reserved.