OBJECTIVETo investigate the rule of lymph node metastasis in colorectal cancer and its affecting factors, and to provide clues for clinical diagnosis and treatment of colorectal cancer patients.

METHODSThe clinical data of 1166 cases of colorectal cancer receiving surgical resection were analyzed retrospectively.The relationships between clinicopathologic variables and lymph node metastases were evaluated by crosstabs and logistic regression in SPSS 10.0 for windows.

RESULTSThe rate of lymph node metastasis in colorectal cancer was 49.7%. After entering crosstabs estimation, gender and tumor site were not significantly correlated with lymph node metastasis in colorectal cancer(chi2=1.46, r=0.035, P>0.05 and chi2=3.86, r=0.012, P>0.05). Age, tumor size, the massive type of the tumor, the differentiating degree of the tumor, histology type and the depth of tumor invasion were proved to be independent factors influencing the lymph node metastasis in colorectal cancer (chi2 =13.1, r=0.064, P<0.05 and chi2=77.161, r=0.245, P<0.01 and chi2=144.831, r=0.341, P<0.01 and chi2=128.310, r=0.318, P<0.01 and chi2=120.418, r=0.319, P<0.01 and chi2=227.287, r=0.434, P<0.01). After entering logistic regression estimation, the correlativity of risk factor of lymph node metastasis in colorectal cancer: the depth of tumor invasion > the massive type of the tumor>the differentiating degree of the tumor > tumor size. Preoperative blood serum CEA level was significantly correlated with lymph node metastasis (chi2=509.599, r=0.661, P<0.01).

CONCLUSIONThe depth of tumor invasion is the most risk factor of lymph node metastasis in colorectal cancer. Preoperative high level of blood serum CEA indicates the occurrence of lymph node metastasis.