Clinical Value Of Detection Of Circulating Tumor Cells Of Breast Cancer By Nested RT-PCR

Objective:To evaluate the clinical value of detection of circulating tumor cells of breast cancer by the optimized nested RT-PCR using cytokeratin 19(CK19) and small breast epithelial mucin(SBEM).Methods:The reverse transcripted products of the gradient mixture of the RNA of MCF-7 cells and peripheral mononuclear cells of healthy volunteers were detected by the optimized nested-RT-PCR to evaluate its sensitivity,peripheral blood of 10 healthy volunteers and 20 patients of benign lesions of breast were detected to evaluate its specificity,and peripheral blood of 56 patients of breast cancer were detected.Results:The optimized detecting system could detect 1 MCF-7 cell from peripheral mononuclear cells of 3ml peripheral blood,no positive expression of CK19 mRNA and SBEM mRNA were found in 10 healthy volunteers and 20 patients of benign lesions of breast.The positive rate of CK19 mRNA was 33.9%.The positive rate of SBEM mRNA was 28.6%.The rate that either CK19 mRNA or SBEM mRNA was positive was 42.9%.The positive expression of CK19 mRNA and SBEM mRNA in the tumor size group of≤2cm,2~5cm and >5cm were 13.3%,32.3%,70% and 6.7%,25.8%,70%, in the group of lymph node positive and negative were 43.2%,15.8% and 37.8%,10.5%,in the TNM stage group of I,II and III+IV were 14.3%,25.8%,75% and 7.1%,23.3%,66.7%,in the clinicopathological type group of invasive ductal carcinoma, invasive lobular carcinoma and ductal carcinoma in situ(DCIS) were 34.0%,25.0%,50.0% and 30.0%,25.0%,0%,in the group of ER positive and negative were 34.2%,33.3% and 34.2%,16.7%,in the group of PR positive and negative were 36.0%,32.3% and 28.0%,29.0%, in the group of C-erbB-2 positive and negative were 40.6%,25.0% and 34.4%,20.8%.After the statistical analysis,the expression of the two markers were related to the size of primary tumor,axillary lymph nodes status and TNM(P<0.05),but not related to the status of ER,PR and C-erbB-2(P>0.05).Conclusions:The optimized nested-RT-PCR system achieved higher sensitivity and specificity,could detect the expression level of CK19 mRNA and SBEM mRNA effectively in the peripheral blood of breast cancer patients;CTC detection was useful for the assessment of prognosis and treatment of breast cancer patients.