Multivariate Regression Analysis Of Lateral Lymph Node Metastasis In Middle And Low Rectal Cancer

Objective To explore the necessity of lateral pelvic lymphadenectomy in middle and lower rectal cancer. To analyse the relationship between lateral lymph node metastasis in middle and lower rectal cancer and the clinical parameters such as patient’s sex, age, the distance of the tumor and the dentate line, the tumor’s size, infiltration extent around bowel wall, the infiltration depth, preoperative serum CEA concentration and expression of Ki-67and E-cad.Methods Detecting the content of serum CEA concentration preoperatively; observing the distance of the tumor and the dentate line,the tumor’s size and the infiltration extent around bowel wall during operation; the detecting the concentration of Ki-67and E-cad by immunohistochemistry, the infiltration depth and the lateral lymph node metastasis after operation. Collected data will be tested about univariate analysis by the use of SPSS13.0statistical software package. Factors, which are significant about single factor analysis, will be analyzed about multifactorial logistic regression analysis.ResultsThe results of univariate analysis1、There is no obvious relevance between lateral lymph node metastasis and parameters such as patient’s sex, age, tumor’s location, size, infiltration extent around bowel wall and the expression of E-cad, and their differences have no statistical significance(P>0.05). However, there was a tendency that the closer of the tumor from the anal, the larger the diameter of tumor, the higher incidence of lateral lymph node metastasis.2、It is showed that the lateral lymph node metastasis is significantly correlating with the infiltration depth, serum CEA concentration and expression of Ki-67(P<0.05). And we can find that with the increases of the infiltration depth and serum CEA concentration, the lateral lymph node metastasis rate increased. The patient with Ki-67negative expression had a higher rate of lateral lymph node metastasis than the ones with Ki-67positive expression,and the difference has statistical significance (P=0.012).(table1).The results of multifactorial logistic regression analysis.Multifactorial conditional logistic regression model was used to analyse the factors of depth of tumor invasion, expression of Ki-67and serum CEA concentration. It is showed that Ki-67is a protective factor of lateral lymph node metastasis in middle and lower rectal cancer (B=-22.302, OR<1).However, all factors which were studied had no statistical significance (P>0.05)Conclusions1, The rate of lateral lymph node metastasis in middle and lower rectal cancer is low, only for8.7%.Therefore, routine lateral pelvic lymphadenectomy is not reasonable.2、Depth of tumor invasion, expression of Ki-67and serum CEA were significantly telated to the lateral lymph node metastasis in middle lower rectal cancer,which are of some reference value to the options of rectal cancer surgery program in the clinic.