KI-67 Expression And Clinical Significance In Childhood Bladder Rhabdomyosarcoma

OBJECTIVES AND BACKGROUND:Rhabdomyosarcoma(RMS)is the most common soft tissue tumor in children and adolescents,accounting for 5%of pediatric tumors.It is estimated that every year 350 new cases are diagnosed in patients under 20 in the United States.Whereas,,RMS is very rare in adults.Relatively more common in male but without clinical significance(1.4 times more common in men than in women).Rhabdomyosarcoma can occur in any part of the body,but the mechanism of rhabdomyosarcoma and genetic mechanismhave not been fully elucidated.Recent article summarized the genome-wide study and identified the prognostic value of the PAX-FKHR fusion gene in RMS,implicating in the mechanism of tumor escape inhibition.However,these findings could not be directly translated to identifying biomarkers for the diagnosis and prognosis of RMS and predicting response to Targeted therapy for individuals in clinical practice,so as to improve the prognosis of rhabdomyosarcoma.Therefore,it is important to identify a biomarker that can be easily prepared to predict the survival of cancer patients(eg,pathological staging system,clinical staging system,molecular biomarker).Ki-67 protein could be identified in the cell cycle,which is closely related to cell proliferation.In the urinary tract tumors,most of the literatures suggested that Ki-67 protein expression in urinary tumors is highly correlated with tumor grade,TNM stage,postoperative recurrence,metastasis and prognosis,especially in its postoperative prognosis.However,the study of KI-67 in rhabdomyosarcoma is still very rare.Therefore,Immunohistochemistry was used to detect the expression of Ki-67 protein in rhabdomyosarcoma and to explore the relationship between Ki-67 and rhabdomyosarcoma.METHODS:Twenty-six children with bladder rhabdomyosarcoma were enrolled in this study in the ZhuJiang Hospital of Southern Medical University from January 2010 to January 2016.Including 23 males and 3 females;aged from 1 to 9 years old,with an average age of 3.7±1.5 years.The expression of KI-67 protein in these tumor specimens was detected by immunohistochemical SP method.Statistical analysis was performed by using the commonly used statistical software IMB SPSS 20.0.The expression of KI-67 protein was correlated with age,tumor size(cm).The expression of KI-67 protein was analyzed by the method of chi-square analysis,and the expression of KI-67 protein was analyzed by chi-square analysis.The expression of KI-67 protein was correlated with sex,muscular invasion,positive margin and the number of tumor.Clinical stage.Clinical group and risk stratification.Kaplan-Meier test was used to analyze the relationship between the expression of KI-67 protein and the prognosis of rhabdomyosarcoma in children.Finally,we also explored the changes of KI-67 protein expression in children with rhabdomyosarcoma before and after chemotherapy.RESULTS:The expression of KI-67 was not correlated with the sex and age of the patients.Moreover,we found that the expression of KI-67 protein was not significantly correlated with tumor size,positive margin,muscular invasion and the number of tumor,but was significantly correlated with number of lymph node metastases(P=0.033,0.05>P>0.01).The expression of KI-67 protein in children with rhabdomyosarcoma was not significantly correlated with clinical stage,the clinical group and the risk stratification.Kaplan-meier test of prognosis demonstrated that there was statistically significant differences in survival between KI-67 high expression and KI-67 low expression group.(P=0.0108,P<0.05).Patients with low expression of KI-67 had a better prognosis than those with high Ki-67 expression.CONCLUSIONS:Children with low KI-67 expression bladder rhabdomyosarcoma have better prognosis than those with high expression of Ki-67,suggesting that KI-67 protein expression might be a prognostic biomarker in children with rhabdomyosarcoma.