Role Of Pathological Biomarkers And Dynamic Enhanced Magnetic Resonance Imaging In Evaluating The Response Of Neoadjuvant Chemotherapy Of Breast Cancer

[Objective] 1. To investigate the relationship between the expression of ER, PR. P-gp, Ki-67 and Her-2 and the therapeutic response of neoadjuvant chemotherapy (NAC) of breast cancer.2. To investigate the value of MRI in evaluating the therapeutic response of neoadjuvant chemotherapy of breast cancer.3. To compare the accuracy of MRI and pathology in terms of residual tumor size after NAC.[Materials and Methods] MRI was preceded to 114 patients who were pathologically diagnosed of invasive breast cancer via core needle biopsy before and after CET regimen NAC. A series of tumor biomarkers including ER, PR, Her-2, P-gp and Ki-67 was tested by IHC in the specimens of both core needle biopsy and radical mastectomy. The changes of the tumor biomarkers’ expression and the shrunk tumor were observed. The changes in residual tumor after NAC were compared in terms of MRI and pathology. The accuracy of MRI was evaluated in not only the size of residual tumor but also the therapeutic effect of NAC. By observing the changes of tumor biomarkers before NAC and after operation, the therapeutic effect and the prognosis of NAC were estimated.[Results] The P-gp expression before chemotherapy was associated with the effect of NAC. The up-regulation of P-gp expression after NAC was associated with poor therapeutic effect (P=0.0011). The expression of Ki-67 was significantly down-regulated (P<0.0001) but it had no association with NAC response (P= 0.9645). The mean size of residual tumor after NAC detected by MRI was (20.83±14.31) mm and that of pathological specimen was (18.89±12.83) mm, MRI overestimated the residual tumor size. In our study, the sensitivity of MRI was 95.12%, the specificity was 28.57%, the positive predictive value was 79.59% and negative predictive value was 66.67%.[Conclusion] Multivariable logistic regression indicated that the amount of metastasis lymph nodes and P-gp status were important factors for pCR acquisition. The positive transition of P-gp after NAC indicated the increase of drug resistance of chemotherapy. The down-regulation of Ki-67 was associated with the decline of tumor proliferation. The evaluation of the efficacy of NAC either by MRI or pathology did not reach satisfied consistency. Due to the limited sample, the survival curves did not come to the consistency with efficacy. More samples need to be accumulated and studies to be applied.