Purpose: To identify the risk factors for apical node metastasis in colorectal cancer (CRC) patients who underwent laparoscopic radical resection with D3 lymphadenectomy.
Methods: The subjects were 578 consecutive patients who underwent laparoscopic radical resection with D3 lymphadenectomy for CRC between February, 2003 and December, 2009. The Cox proportional regression model was used to evaluate the association between apical node metastasis and survival and the logistic regression model was used to identify the risk factors for apical node metastasis.
Results: Thirty patients (5.2 %) had apical node metastasis, which was an independent risk factor for poor disease-free survival [hazard ratio (HR) = 3.02, P = 0.019]. Multivariate logistic regression analysis revealed that poor differentiation [odds ratio (OR) = 4.58, P < 0.001] and ulcerative/infiltrative morphology (OR = 5.57, P = 0.023) were independent risk factors for apical node metastasis. In the subgroup analysis based on pT3-4 tumors, multivariate logistic regression analysis also suggested that these factors were significantly associated with apical node metastasis.
Conclusions: Apical node metastasis is an independent risk factor for poor oncologic outcome. T3-4 stage, poor differentiation, and ulcerative/infiltrative morphology are significantly associated with apical node metastasis. Notably, in this study, T1-2 stage tumors had no apical node metastasis, suggesting that D3 lymphadenectomy may be over-performed without considering the T stage of tumors.