Effects of taxane-anthracycline and taxane only treatment on cardiac function in breast cancer-a retrospective cohort study.

Introduction: Cardiotoxic, anthracycline-based therapies have high value in selected patients with breast cancer. We aimed to describe the effect of anthracycline plus taxane and single taxane chemotherapies on echocardiographic parameters in women with breast cancer.

Methods: We retrospectively analysed data of 68 women (> 18 years old) treated for breast cancer in 2018-2021 in the Cardiology Outpatient Clinic of Semmelweis University, Department of Internal Medicine and Oncology. Cardiovascular medical history was collected at baseline and transthoracic echocardiography was completed at each visit. Also, we reviewed electronic medical records for other relevant medical information. Measured echocardiography parameters were assigned to five periods (0-14 days, then every half year and beyond day 545) based on the time since the first treatment. Trajectories of ejection fraction and diastolic function associated markers over the follow-up periods were analysed by linear mixed models.

Results: Mean age of the anthracycline plus taxane group was 52.7 ± 14.1 years, of the single taxane group 55.2 ± 13.1 years. The mean anthracycline dose was equivalent to 240 mg/m² of doxorubicin. Overall pre-existing cardiovascular burden was low. Statistically significant changes were found only in the anthracycline plus taxane group: ejection fraction decreased mildly from 65.5 ± 3.1% at baseline to 62.1 ± 3.2% at 181-365 days (p = 0.007) while deceleration time decreased mildly from 227.9 ± 33.9 msec to 197.4 ± 29.4 msec at 15-180 days (p = 0.028). Both drops were only temporary and values neared baseline values over follow-up (p = NS vs. baseline). Other important determinants of ejection fraction were age and hypertension among the investigated risk factors.

Conclusion: Our study confirms the overall safety on cardiac function of both single taxane and anthracycline plus taxane chemotherapy, as we found no changes in echocardiographic parameters associated with single taxane therapy, while anthracycline plus taxane chemotherapy was associated with a temporary and clinically insignificant reduction of ejection fraction and deceleration time over 1.5 years of follow-up. Our study is limited by its retrospective nature and the low number of participants.