Abstract:

Objective

To assay cancer cells in peripheral blood of breast cancer patient using CK19m RNA as gene marker and analyze the variation of CK19m RNA expression before and after chemotherapy and its relation with clinical pathologic factors,and compare the variation of CK19m RNA expression under different chemotherapy regimens.

Methods

RT-PCR was used to assay the expression of peripheral blood CK19m RNA in 217 breast cancer patients,including 176 cases of infiltrative ductal carcinoma(IDC group),17 in situ ductal carcinoma(DCIS group)and 24 metastatic breast cancer(MBC group).Among the 217 patients,only 67 completed routine blood taking and examination dwing the whole process of chemotherapy.The variation of peripheral blood CK19m RNA copy number before and after chemotherapy and its relation with clinicopathological factors of these 67 patients were analyzed.Chemotherapy included CEF regime(Cyclophosphamide 600 mg/M ²,Epirubicin 90 mg/M ²,5-Fluorouracil 500 mg/M ²,CEF group n=23),TEC regime(Paclitaxel 140 mg/M ²,Epirubicin 90 mg/M ²,Cyclophosphamide 600 mg/M ²,TEC group n=28)and TP regime(Paclitaxel 140 mg/M ²,Cis-platinum 60 mg/M ²,TP group n=16).There was a total of 6 cycles,21 days as one cycle.Kruskal-Wallis test and Wilcoxon ran sum test were used for statistical analysis,for the distribution of CK19 m RNA copy numbers data of the 217 cases was not a normal distribution.

Results

Between the three groups of IDC group,DCIS group and MBC group,the peripheral blood CK19m RNA copy numbers were statistically different(P=0.048);the median number of the MBC group was higher than that of the other two groups(P＜0.050).For the 67 patients,the peripheral blood CK19m RNA copy number variation before and after chemotherapy was statistically different among subgroups of clinical stageⅠ-Ⅳpatients;the median number of the clinical stageⅣpatients was higher than that of stagesⅠ-Ⅲpatients(P＜0.050).The median number of peripheral blood CK19m RNA copy number variation before and after chemotherapy was higher in PCNA positive patients than in PCNA negative patients,with statistical difference between the two(P=0.032).The peripheral blood CK19m RNA copy number variations before and after chemotherapy in tumour size,lymph node metastasis,histological stage,ER,PR,and HER-2 had no statistical difference(P＞0.050).The peripheral blood CK19m RNA copy numbers after chemotherapy in the three chemotherapy groups all changed,there was a statistical difference between the three groups(P=0.011).

Conclusion

The peripheral blood CK19mRNA expression of breast cancer can be used to assay distance metastatic status.TEC has stronger effect on CK19mRNA expression of peripheral blood compared with TP and CEF chemotherapy regimes,so the assessment of peripheral blood CK19mRNA expression can indirectly provide an reference for postoperative chemotherapy.

Key words: Breast neoplasms, Periferal blood, CK19 mRNA expression, Chemotherapy