engleski

O146 Prediction of reversibility of cardiotoxicity caused by immunotherapy with trastuzumab

Introduction: Cardiotoxicity is the most important side effect of trastuzumab, humanized monoclonal antibody to the HER2 protein in use for immunotherapy of breast cancer. It is mainly manifested as a reduction in left ventricular contractility without myocardial necrosis and the process is therefore mostly reversible. However, sometimes the disease can progress to irreversible dilated cardiomyopathy. Objectives: Aim of the study is to distinguish factors that can at first appearance of cardiotoxicity, with a certain probability, determine whether the process is reversible or irreversible. Methods: In this prospective study, we have analyzed 387 patients (pts) with non-metastatic breast cancer, treated with trastuzumab for one year with the standard adjuvant therapy protocol. Cardiotoxicity was defined with the reduction of left ventricular ejection fraction (LVEF) by 15% from the baseline or by 10% of normal values. Echocardiography was performed before the beginning and in three months period during therapy. If cardiotoxicity was established, pts were suspended from the trastuzumab therapy, with monthly echocardiography controls. Results: Cardiotoxicity was established in 51 pts (13.17%) and they were divided in two groups. Complete recovery of the cardiac function was found in 28 pts (54.9%, assorted to group A) and they managed to finish trastuzumab protocol. Due to only partial recovery of the cardiac function or cardiotoxicity after readministration, trastuzumab therapy was not finished in 23 pts (45.1%, assorted to group B). Pts in group B had significantly greater reduction of LVEF (A:B¼27:15 %, p<0, 0001) and in those pts trastuzumab was started earlier after prior chemotherapy (A:B¼33, 5:27 days, p¼0, 037). As expected the mean NT-proBNP level in the serum was significantly higher in group B (A:B¼92, 3:134, 7 ng/L, p¼0, 01). There was no significant effect of age, body mass, hypertension, stage, histology grade or the side of the tumor, expression of the estrogen or progesterone receptors and the ACE gene polymorphism on recovery of the cardiac function. Conclusion: Trastuzumab induced cardiotoxicity is more likely to be irreversible in pts with more extensive fall of the EFLV. If the drop is more than 25% we suggest not to readminister trastuzumab. Time between prior chemotherapy and administration of trastuzumab shorter than 30 days is more often associated with irreversible cardiac impairment.

cardiotoxicity, reversibility, trastuzumab, prediction

nije evidentirano