Abstract: Objective To investigate the results of echocardiographic detection and the incidence of left ventricular systolic dysfunction during medication with trastuzumab following treatment with anthracyclines in patients with human epidermal growth factor receptor 2 (HER-2) positive early-stage breast cancer, and to provide reference for rational drug use. Methods The results of echocardiographic detection of patients with early-stage breast cancer treated with trastuzumab following anthracyclines in a big hospital between July 1, 2016 and December 31, 2019 were collected. At baseline (T1), before administration of anthracycline (T2), during trastuzumab administration (T3) and when trastuzumab therapy was finished (T4), the detection rate of echocardiography, the number of times of echocardiographic detection at T3 and the changes of left ventricular ejection fraction (LVEF) were analyzed. Results Among the 60 patients with breast cancer who met the inclusion and exclusion criteria, 15.00%, 58.33%, 51.67% and 11.67% underwent echocardiographic detection at T1, T2, T3 and T4. At T3, the composition ratio of the number of times of echocardiography detection was 41.94% (once), 25.81% (twice), 29.03% (three times) and 3.23% (four times) respectively. There was no significant decrease in LVEF (P<0.05) after treatment, However, LVEF decreased when trastuzumab was used (P>0.05), but by less than 10%. Its damage to the heart was below the diagnostic criteria of cardiotoxicity. Conclusion Failure to effectively monitor the left ventricular systolic function during medication with trastuzumab following the anthracyclines therapy may pose a risk to the safety of patients.

Key words: breast neoplasms, anthracyclines, trastuzumab, cardiotoxicity, echocardiography