Risk factors for lymph node metastasis in early colon cancer

The aim of the study was to determine factors predicting lymph node metastasis in patients with T1 or T2 colon cancer. A total of 906 patients with T1 or T2 colon cancer who underwent colon resection with regional lymphadenectomy in a tertiary hospital, from January 2008 to December 2013, were analyzed. The prognostic factors for LN metastasis and the risk factors for survival were analyzed. There were 728 patients (80.4%) without lymph node metastasis (LN-negative group) and 178 patients (19.6%) with lymph node metastasis (LN-positive group). Tumor invasion depth (P < 0.001), lymphatic invasion (P < 0.001), and perineural invasion (P = 0.008) were significantly different between the two groups. During the median follow-up period of 69 months, the 5-year disease-free survival rate was 98.6% for the LN-negative group and 92.8% for the LN-positive group (P ≤ 0.001). In multivariate analysis, influencing factors associated with disease-free survival rate were LN metastasis (P = 0.001) and perineural invasion (P = 0.040). Female, depth of tumor invasion (P = 0.001), and lymphatic invasion (P < 0.001) were significant independent predictive factors for lymph node metastasis in multivariate analysis. Positive LN status predicted poor disease-free survival in patients with early cancer. This suggests that depth of tumor invasion ≥ sm2 and the presence of lymphatic invasion in early colon cancer provide useful information to determine which patients would benefit from radical surgery.