Abstract & Overview
Background: Cancer therapy-related cardiac dysfunction (CTRCD) is a new term that encompasses a wide range of potential manifestations and is etiologically associated with a wide variety of cancer treatments. Detection of early subclinical cardiac dysfunction is of great clinical importance. Objective: To assess subclinical CTRCD in women with HER2-positive locally advanced or metastatic breast cancer undergoing a course of anthracyclines (doxorubicin), docetaxel, and trastuzumab. We prospectively enrolled women aged 18-75 years with an established diagnosis of HER2-positive locally advanced or metastatic breast cancer across 3 centers. Material and methods: We monitored 122 women with HER2-positive locally advanced or metastatic breast cancer undergoing a course of anthracyclines (doxorubicin), docetaxel, and trastuzumab using speckle-tracking echocardiography. Based on the treatment protocol, we formed 3 comparison blocks: block 1 (chemotherapy: doxorubicin+cyclophosphamide); block 2 (chemotherapy+targeted therapy: docetaxel+trastuzumab), and block 3 (targeted therapy: trastuzumab). Results: The rate of subclinical CTRCD detection was high and exceeded 20%-30% in all comparison blocks after the 3rd course of chemotherapy, chemotherapy+targeted therapy, and targeted therapy. The rate of subclinical CTRCD increased significantly from the 1st to the 2nd, from the 2nd to the 3rd, from the 3rd to the 4th therapy courses in each block. Comparisons between the blocks were significant only after the 4th course of chemotherapy and the 4th course of targeted therapy (Yates-corrected chi-square, P=.0394); all the other comparisons between the blocks were not significant in terms of subclinical CTRCD rate. Discussion: Given the growing number of patients with breast cancer, such frequent monitoring of the cardiac function is likely to improve the quality of cancer treatment and might have a positive impact on the overall survival of patients with breast cancer. Conclusions: Criteria for frequency of echocardiographic monitoring of cardiac dysfunction in patients with malignant tumors, especially with HER2-positive breast cancer, should be revised.