ABSTRACT
With the widespread clinical application of neoadjuvant chemotherapy, it has become an essential part of combination therapy for patients with breast cancer. However, a rapid, accurate, and effective approach for assessing the therapeutic efficacy of neoadjuvant chemotherapy is unavailable. Routine physical examinations cannot provide effective clinical evaluation. Although imaging techniques play an important role in evaluating the therapeutic effect of neoadjuvant chemotherapy, this is limited because it only detects morphologic changes. Blood oxygen detection for breast diseases is an emerging diagnostic technique that has distinctive merit in assessing the efficacy of chemotherapy. Biologic markers are becoming more important in assessing the effect of neoadjuvant chemotherapy for patients with breast cancer. This review summarizes the principles and the current applied practice of these approaches to evaluate the effect of neoadjuvant chemotherapy for patients with breast cancer.
Subject(s)
Female , Humans , Biomarkers, Tumor , Metabolism , Breast Neoplasms , Diagnosis , Drug Therapy , Metabolism , Chemotherapy, Adjuvant , Evaluation Studies as Topic , Magnetic Resonance Imaging , Mammography , Molybdenum , Neoadjuvant Therapy , Oxyhemoglobins , Metabolism , Positron-Emission Tomography , Ultrasonography, MammaryABSTRACT
<p><b>OBJECTIVE</b>To filtrate breast cancer resistance protein (BCRP)-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance.</p><p><b>METHODS</b>MTT assay was performed to filtrate BCRP-mediated resistant agents with BCRP expression cell model and to detect chemosensitivity of breast cancer tissue specimens to these agents. A high performance liquid chromatography (HPLC) assay was established, and was used to measure the relative dose of intracellular retention resistant agents. RT-PCR and immunohistochemistry (IHC) were employed to investigate the BCRP expression in breast cancer tissue specimens.</p><p><b>RESULTS</b>MTT assay showed that the expression of BCRP increased with the increasing resistance of 5-fluorouracil (5-Fu) (P<0.05, n=3) in the cell model, while HPLC assay indicated that the intracellular retention dose of 5-Fu was significantly correlated with the expression of BCRP (r=-0.897, P<0.05, n=3). A total of 140 breast cancer tissue specimens were collected. BCRP-positive expression was detected in forty-seven specimens by both RT-PCR and IHC. As shown by MTT assay subsequently, the resistance index (RI) of 47 BCRP-positive breast cancer tissue specimens to 5-Fu was 7-12 times as high as that of adjacent normal tissue samples. BCRP expression was related to 5-Fu resistance (R2=0.8124, P<0.01).</p><p><b>CONCLUSION</b>Resistance to 5-Fu can be mediated by BCRP. Clinical chemotherapy for breast cancer patients can be optimized based on BCRP-positive expression.</p>