Study On Chemosensitivity And Prognosis Of Breast Cancer

Background and purpose:It is difficult to overcome the problem of drug-resistance in breast cancer patients. This study is based on the anti-microtubules drugs(including epothilone B and taxanes), for the aim to analysize the resistant factors including resistant protein and miRNA. First, it was reported that MRP7may contribute to the resistance of epothilone B,so the patients with epothilone B only in one of our phase I clinical trials were enrolled in our study.We detect the expression of MRP7in vivo and hope to find the relationship between epothilone B and MRP7. Second, taxanes based chemotherapy was one of the most common choices in breast cancer treatment. The type of luminal A was only partly sensitive to chemotherapy, including taxanes based chemotherapy. The aim of our study is to find the biomarkers of chemotherapy resistance by detecting miRNAs in serum, which may give direction to clinical treatment choice in the type of luminal A breast cancer patients.Methods:First, based on the epothilone B phase I clinical trial in our department, we collected blood samples from patients at different time points, to detect the pharmaco kinetic parameters. We want to find the relationship between MRP7expression and epothilone B pharmacokinetics as well as efficacy by detecting MRP7protein expression in cancer tissue and peripheral blood with immunohistochemistry and flow cytometry respectively. Winnonlin pharmacokinetic statistics software was used to make blood drug concentration-time curve fit. To get pharmacokinetic parameters of epothilone B in vivo, the trapezoidal area method was used to estimate AUC. Confidence interval method was used to evaluate the relationship between pharmacokinetic parameters and drug doses. Standard curve regression equation was obtained by regression analysis. Double variable spearman correlation analysis was used between two groups. All inspection was bilateral, with standards of alpha=0.05, P<0.05indicates statistical significance. Secondly, obtain the serum sample of luminal A type breast cancer patients who received anthracycline combined with taxanes (AT) regimen before surgery. Based on the sensitivity differences to AT regimen, sensitive and resistant groups were separated, total RNA in serum was extracted. As a pool,6samples of accurate matching patients were selected in sensitive and resistant groups respectively. After pre-amplification, TaqMan Real-time PCR chip was used to detect differentially expressed miRNAs. Selected38cases from sensitive group, and30cases from drug-resistant group with well-balanced clinical pathologic features. Fluorescence quantitative polymerase chain reaction (PCR) was used to verify the miRNAs with apparent differences from chip screening in a larger sample size. Analyze the results after confirmation and explore the predictive value of these miRNAs in chemosensitivity. RQ manager1.2and Data Asist V2.0software was used to analyze the chip. SPSS16.0software was used for statistical analysis. Statistical description was used to describe the clinical pathological features, t test (Student’s t test) was used to analyze measurement data; Mann-Whitney U in nonparametric test was used to analyze the continuous variable. P value was bilateral tested less than0.05was regarded as statistical significance.Results:First, pharmacokinetic:we found the average fluorescence intensity from peripheral blood MRP7and the pharmacokinetic parameters including AUC (P=0.001), t1/2β (P=0.039), the Cmax (P=0.017) and Cl (P=0.001) were significantly correlated. Negative correlation was found in the MRP7fluorescence intensity and AUC, t1/2β, Cmax, and positive correlation was found both in MRP7fluorescence intensity and positive staining cells with Cl (P=0.026). However, MRP7in tissue does not show obvious correlation with pharmacokinetic parameters. Efficacy:MRP7expression levels in tissue were high in all of the17patients. But for the only one who got partial response (PR), her MRP7expression in tissue was relatively low, and MRP7average fluorescence intensity was relatively weak in peripheral blood. These data showed that MRP7expression may have relationship with efficacy. At the same time, the AUC, tl/2β in the only patient who got response were the highest in the three patients with same dose level, and her Cl was the lowest in all of the17patients. These data indicated that the pharmacokinetic parameters of AUC, tl/2(3and Cl might have correlation with efficacy. Second, based on217differentially expressed microRNAs screened by miRNA chip, we selected9miRNAs which show more apparent differences between the two groups, and gave validation in68cases of type luminal A breast cancer (30cases from resistant group,38cases from sensitive group). Results show that the let-7b, miR-205, miR-19a and miR-27a were obviously different between the two groups. The difference was statistically significant (P<0.05). Among them, miR-19a and miR-27a showed more significant difference with1.56fold between the two groups than the other two miRNAs. Conclusion:First, MRP7expression may influence drug pharmacokinetic parameters in breast cancer patients, and may have a tendency to affect efficacy. At the same time, there may be correlation between pharmacokinetic and efficacy. Second, miR-27a-3p%miR-19a-3p/、miR-205-5p and let-7b-5p miRNAs in serum of breast cancer patients with luminal A type are associated with chemosensitivity. Objective To analyze the clinicopathological feature and prognostic factors of breast cancer patients with inguinal lymph node metastasis.Methods From January1999to December2010,17breast cancer patients with inguinal lymph node metastasis were treated in our cancer center. All of the patients had a history of breast cancer without the other primary cancer. Clinicopathological characteristics, prognostic factors were surveyed.Results The frequency of breast cancer cases who occurred inguinal lymph node metastasis was0.11%in the period.2patients (11.8%) had inguinal lymph node metastasis only, multi-sites metastases were observed in the remaining15(88.2%) patients. The number of ER and/or PR-positive and negative were10(58.8%) and7(41.2%) respectively, and in the13cases who underwent HER-2test, the number of HER-2-positive was4(30.8%). For the16patients who underwent surgery,9patients were detected metastatic axillary lymph nodes equal or greater than4. All of the17patients were treated with chemotherapy. The median follow-up time was156months. The5year overall survival was49.9%. Univariate analysis revealed that metastatic axillary lymph nodes>4, ER and (or)PR negative, adjuvant chemotherapy<6cycles, disease stage as III/IV at diagnosis and the period from diagnosis of breast cancer to the occurrence of inguinal lymph node metastasis<36months were predictors of shorter PFS (P<0.050). Metastatic axillary lymph nodes>4, ER and (or)PR negative, adjuvant chemotherapy≤6cycles, primary recurrence as multiple distant metastases, the period from diagnosis of breast cancer to the occurrence of inguinal lymph nodes metastasis≤<36months and pleural effusion were predictors of shorter OS (P<0.05).Multivariate analysis revealed that the period from diagnosis of breast cancer to the occurrence of inguinal lymph node metastasis was the only independent prognostic factor concerning PFS(P<0.05).Conclusions The prognostic factors of breast cancer patients with inguinal lymph node metastasis included the number of metastatic axillary lymph nodes, ER and (or) PR status, the cycles of adjuvant chemotherapy, type of primary recurrence, the period from diagnosis of breast cancer to the occurrence of inguinal lymph node metastasis and pleural effusion. Regular and complete physical examination after surgery as well as prompt intensive treatment for high-risk patients may have positive significance in the treatment of such type of patients, still, a type of more reasonable and individualized treatment must be in need in future.