The Value Of CTnI Measurement In Prediction Of Anthracycline Induced Cardiotoxicity In Breast Cancer Patients

Objective Anthracyclines, such as doxorubicin and epirubicin, are active antisneoplatic agents that are commonly used in the chemotherapy of breast cancer, which can decrease the mortality significantly. The most serious side-effect of these drugs is dose-dependent cardiomyopathy. The highest risk is associated with chronic administration, when congestive heart failure (CHF) may develop. CHF is usually seen in 1 year after the chemotherapy, sometimes, even in severe years later. Therefore, monitoring of cardiac function is essential both during and after the administration of anthracycline-containing chemotherapy, which is able to select the high-risk patients suffering congestive heart failure.186 breast cancer patients who had been scheduled to receive anthracycline-containing combination chemotherapy were included in this study. And serum cardiac troponin-Ⅰ(cTnⅠ) levels and left ventricular ejection function (LVEF) were measured in order to find the value of cTnⅠmeasurement in prediction of anthracycline induced CHF in breast cancer patients.Methods 1. In case of the evaluable 186 patients the following chemotherapy protocols were used:6 cycles of TE regimen (75mg/m2 epirubicin and 75mg/m2 docetaxel,Ⅳ, d1 q3w); 4 cycles of EC (75 mg/m2 epirubicine and 600mg/m2 cyclophosphamide,Ⅳ, d1 q3w) followed by 4 cycles of T (75mg/m2 docetaxel,Ⅳ, dl q3w).2. Monitoring data:the cTnⅠlevels were measured by immunoassay (ADVIA(?) CentaurTM CP system) 1day before the first cycle of chemotherapy (labeled CO) and on the second day of every cycle (labeled C1-C6). Values were considered normal bellow 0.10 ng/ml, therefore, the determination of a CTnⅠconcentration 0.10 was considered to represent an elevated serum level (CTnI+), and all measurements <0.10 ng/ml were scored as cTnⅠ-. Left ventricular ejection fraction (LVEF) was assessed by echocardiography 1 week before beginning chemotherapy, and then the 2nd,4th,and 6th months after the begining of chemotherapy (labeled M0, M2, M4, and M6). In this study, we defined toxic events of heart as below:①LVEF decreases more than 10%. (2)CHF。This study started at the first echocardiography, and deterioration was not labeled until toxic events appeared, lost follow-up was defined as no toxic event happening in the follow-up 6 months. This study ended on Oct.30th,2010.Results 1.1116 cTnⅠvalues were detected during the 1st cycle to the 6th cycle regimen, in which 136 values is equal to or greater than 0.1ng/ml(12.2%,136/1116). Patients were allocated to two subgroups according to the cTnⅠvalue detected after chemotherapy:the troponin positive group (cTnⅠ+, n=60,32.6%(60/186)) and the cTnⅠ-group. The baselines of cTnⅠwere similar between cTnI+ and cTnⅠ-group(t=-0.842, P=0.401).There were statistically significant differences between C1-C6 and CO in both cTnⅠ- and cTnⅠ+ group(F= 17.066, P=0.000 and F=17.580, P=0.000). In this study,the raised range of cTnI values detected after the 2nd cycle of chemotherapy was greater than other values both in troponin positive group and negative group. And in cTnⅠ+, cTnⅠvalues went up and down with a peak in the 2nd day after the 2nd cycle regimen.2. In the troponin positive group, LVEF of 16 patients decreased more than 10%(1 case in the 2nd month,5 cases in the 4th month, and 10 cases in the 6th month, totally 26.7%(16/60)). And seven of 126 individuals in cTnⅠ- showed a drop of>10%(2 cases in 4th month, and 5 cases in the 6th month, totally 5.6% (7/126)). No CHF happened in both groups.3. The incidence of toxic events of heart is greater in cTnⅠ+ compared with cTnⅠ-, there were statistically significant differences (x2=17.192, P=0.000).Conclusion The data presented here reveal that elevated serum levels of cTnⅠearly after anthracycline therapy predict subsequent cardiac dysfunction in the breast cancer patients. And the cut-off value for cTnⅠis 0.1ng/ml. The value of cTnⅠcan be used to select the high-risk patients suffering congestive heart failure...