Comparison of cardiac events associated with liposomal doxorubicin, epirubicin and doxorubicin in breast cancer: a Bayesian network meta-analysis

Norihiro Yamaguchi, Takeo Fujii, Shunsuke Aoi, Peter S. Kozuch, Gabriel N. Hortobagyi, Ronald H. Blum

Anthracyclines play a broad and important role in the care of patients with either operable or metastatic breast cancer. However cardiotoxicity narrows the therapeutic index of this drug class leading to potentially clinically meaningful treatment delays or discontinuations. We conducted a Bayesian network meta-analysis, a validated statistical methodology, allowing direct and indirect comparison of cardiotoxicity of different anthracycline and non-anthracycline regimens. We conducted a systematic review of prospective randomised controlled trials through MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Google Scholar comparing non-anthracycline based regimens (NON), doxorubicin (DOX), epirubicin (EPI) and liposomal doxorubicin (LD). We included studies published up to 1st January 2014 in both adjuvant and metastatic contexts. Notably, HER2/neu-targeted regimens were excluded. We assessed the studies' eligibility criteria and data collection with consensus of two independent authors. Our primary outcome measure was cardiac events grade 3 or greater (CE3) in accordance with Common Terminology Criteria for Adverse Events (CTCAE) Version 4.0. A Bayesian pairwise and network meta-analysis was conducted to estimate pooled Odds Ratio (OR). Nineteen randomised controlled trials met eligibility criteria and were included in this analysis. We found a trend showing that LD is less cardiotoxic than DOX with an OR of 0.60 (95% confidence interval (CI) 0.34-1.07) There was no difference between Epi and LD with an OR of 0.95 (95%CI 0.39-2.33). DOX is more cardiotoxic than Non with an OR of 1.57 (95%CI 0.90-2.72). DOX has higher CE3 rates than NON does. LD statistically trended to lower cardiac event rates than DOX. Non-statistical significance among EPI, LD and DOX with regard to cardiac toxicity indicates that avoidance of CE3 should not motivate selection of a particular anthracycline in otherwise healthy women in whom total lifetime anthracycline exposure will likely be limited. Overall low incidence of CE3 with any type of anthracycline indicates that we can safely use any anthracycline if cumulative dose limits are not exceeded. While CE3 does not limit our choice of anthracycline LD appears to be the least cardiotoxic. Takeo Fujii is supported by the grant named Young Investigator Award for Study Abroad in Clinical Epidemiology from St. Luke's Life Science Institution.