Patterns of on-treatment cardiac adverse events within three clinical trials of adjuvant anthracycline-based chemotherapy.

BACKGROUND

This study aims to assess the patterns of development of on-treatment cardiac side effects among patients with early breast cancer receiving anthracycline-based chemotherapy.

METHODS

This is a pooled analysis of patient-level data of patients with early-stage breast cancer who were recruited into three clinical trials to receive different adjuvant chemotherapy regimens. Univariable and multivariable analyses of factors predicting the development of on-treatment cardiac adverse events were conducted through logistic regression analysis. The following factors were evaluated in the univariable analysis: age, menopausal status, body mass index, T stage, and type of chemotherapy protocol.

RESULTS

Among the studied patients, 226 patients (6.7%) experienced 230 incidents of on-treatment cardiac toxicities. Cardiac ischemia was reported among 8 patients, cardiac dysfunction was reported among 19 patients, arrhythmias were reported in 161 patients and other non-specified forms of cardiac adverse events were reported in 42 patients. In univariable logistic regression, the following parameters were predictive of a higher probability of on-treatment cardiac adverse events (P < 0.05): higher age, higher body mass index and FAC chemotherapy protocol. When these factors were included in the multivariable logistic regression analysis, the following factors were predictive of a higher probability of cardiac adverse events: higher body mass index (P = 0.050) and FAC chemotherapy protocol (P = 0.001).

CONCLUSION

On-treatment cardiac events are not uncommon during adjuvant chemotherapy for early breast cancer. Higher dose of anthracyclines and higher body mass index are associated with a higher risk of on-treatment cardiac events.