Incidence And Risk Factors Of The QTc Prolongation In Breast Cancer Patients Induced By Anthracyclines

Objective:To study the incidence and the influenced factors of the corrected QT(QTc)prolongation in breast cancer patients treated with anthracyclines,and to explore ways to reduce or avoid cardiotoxicity induced by anthracyclines.Methods:This is a single center retrospective study.From July 2017 to January 2019,279 female breast cancer patients who underwent 4 cycles of anthracycline treatment in the Department of Breast Surgery of the People's Hospital of Shanxi Medical University were selected.The ECG of all the selected patients before treatment was sinus rhythm and QTc < 440 ms.The most common electrocardiographic abnormalities after treatment were found to be the changes of QTc.Taking QTc ?440ms as the prolongation.According to whether or not the QTc was prolonged,the patients were divided into the QTc prolongation group(n=78)and the QTc non-prolongation group(n=201).The clinical data between the two groups were collected,and influenced factors of the QTc prolongation were analyzed by univariate and multivariate logistic regression.Factors that have statistical significance calculate the incidence of QTc prolongation.Cardiac toxicity was evaluated according to cardiac toxicity symptoms and ECG results during treatment.Results:The common ECG abnormalities after treatment were 78 cases of the QTc prolongation(27.96%),22 cases of ST-T changes(7.89%)and 18 cases of sinus bradycardia(6.45%),etc.Univariate analysis showed that there were significant differences in administration of anthracyclines(contained epirubicin in 48 and 73 cases,pirubicin in 10 and 33 cases,doxorubicin in 4 and 12 cases,liposomal doxorubincin in 16 and 83 cases,?~2=15.54,P<0.01),dexrazoxane use(?~2 =5.43,P=0.02),coronary heart disease(?~2=4.56,P=0.03),overweight or obesity(?~2=4.51,P=0.03)between two groups.Multivariate logistic regression analysis showed that the use of different types of anthracyclines(OR=1.42,95%CI: 1.37-1.48,P= 0.024)and overweight/obesity(OR=1.23,95%CI: 1.16-1.30,P=0.038)were independent risk facors of QTc prolongation.The liposomal doxorubicin in anthracyclines resulted in a minimum incidence of the QTc prolongation of 16.16%(16/99),while epirubicin was up to 39.67%(48/121).Preventive use of dexrazoxane reduced the incidence of the QTc prolongation to 11.43%(4/35).The incidence of the QTc prolongation in breast cancer with coronary heart disease or overweight/obesity is relatively high,which is 66.67%(4/6)and 34.43%(42/122),respectively.No cardiotoxic symptoms such as hypotension,shock,dizziness,syncope,angina and heart failure occurred during the treatment,and no fatal arrhythmia such as ventricular tachycardia and ventricular fibrillation was recorded in electrocardiogram.Conclusion:Although the incidence of the QTc prolongation in breast cancer treated with anthracyclines is high,there is recently no cardiotoxicity such as cardiotoxic symptoms and fatal arrhythmias.Breast cancer patients with coronary heart disease or overweight/obesity are more likely to have the QTc prolongation.Preventive use of dextrazoxan or/and the selection of liposomal doxorubicin in anthracyclines can reduce the incidence of the QTc prolongation.