Expression And Clinical Significance Of The Septin 9 Protein In Monitoring Recurrence And Metastasis After Radical Resection Of Colorectal Cancer

Objective: To explore the value of Septin 9 protein in predicting recurrence and metastasis of colorectal cancer(CRC)after radical resection.Methods: From January 2013 to January2016,a total of 75 patients who were diagnosed with CRC and received radical rsection were enrolled in Qingdao University Affiliated Hospital,49 cases in recurrence and metastasis group(observation group)and 26 cases in non-recurrence and metastasis group(control group).The expression of Septin 9 protein in observation group and control group was determined by immunohistochemistry.The expression of Septin 9 was analyzed in three groups: non-recurrence and metastasis group,distant metastasis group and local recurrence group.The relationship between its expression and clinicopathological parameters and PFS was analyzed.The diagnostic efficacy of Septin 9 protein and serum CEA alone or in combination for recurrence and metastasis of colorectal cancer were evalued.The relationship between Ki-67 and K-ras gene mutant was also discussed.Results:The low expression rate of Septin 9 in patients with recurrence and metastasis after operation was significantly higher than that in patients without recurrence and metastasis(69.4%(34/49)VS 23.1%(6/26)).The expression of Septin 9 protein was closely related to preoperative BMI,clinical stage and lymph node metastasis,but not to sex,age,location of tumors,invasion of blood vessels and nerves.With the increase of pathological stages of colorectal cancer,the lower expression rate of Septin 9 protein,the shorter the PFS.The expression rate of Septin 9 protein in patients with distant metastasis was lower than that in patients without recurrence and metastasis.There was no significant difference in the expression of Septin 9 protein between patients with distant metastasis and patients with local recurrence(P>0.O5).The sensitivity and specificity of Septin 9 protein combined with preoperative serum CEA were 71.4% and 88.5% in the diagnosis of recurrence and metastasis of colorectal cancer after operation.The area under ROC curve was 0.787(P=0.001,95%confidence interval was 0.685-0.890)and it had moderate diagnostic efficacy for recurrence and metastasis after operation.The expression of Septin 9 was negatively correlated with the expression of Ki-67 gene mutant,and it was not related to the expression of K-ras gene mutant.Conclusion:The expression of Septin 9 protein was low in patients with recurrenceand metastasis of colorectal cancer after operation,which was significantly correlated with clinicopathological parameters.There was no significant difference in the expression of Septin 9 between distant metastasis group and local recurrence group.The combined detection of Septin 9 protein and preoperative serum CEA could improve the detection rate of recurrence and metastasis and it could promote cell proliferation,invasion and metastasis as well as Ki-67.The results show that it is closely related to the recurrence and metastasis of colorectal cancer after operation.We hope that this study can provide a reliable reference for clinical diagnosis and treatment.