Conventional cardiac risk factors associated with Trastuzumab induced cardio-toxicity in breast cancer: a meta-analysis
Abstract Funding Acknowledgements Type of funding sources: None. Background Trastuzumab has had a major impact on the treatment of human epidermal growth factor receptor 2(HER-2) positive breast cancer patients. However, it is associated with cardiotoxicity, expressed as an asymptomatic decrease in LVEF and less often as clinical HF. Published studies have tried to identify risk factors predisposing to cardiotoxicity but the results are not uniform. The aim of this meta-analysis is to identify the association of the conventional cardiovascular risk factors:age, smoking, hypertension, hyperlipidaemia, obesity, diabetes mellitus, family history of cardiac disease and the previous history of coronary artery disease (CAD), with the development of Trastuzumab induced cardiotoxicity (TIC). Methods A literature search of PubMed was conducted to identify studies examining the association between cardiovascular risk factors and TIC. The primary outcome of interest was the development of cardiotoxicity manifested as heart failure or deterioration in LVEF based on the criteria presented within each study. We included prospective and retrospective studies of patients with HER2 positive breast cancer who were treated with Trastuzumab. Data were extracted and pooled odds ratios (ORs) with 95% confidence intervals (Cis) were calculated examining the odds of developing TIC for each of the risk factors. Results A total of 35 studies were included in the analysis. Age > 60 years old (OR: 0.7; 95% CI: 0.318-1.09; p = 0.0004), hypertension (OR: 0.69; 95% CI: 0.26-1.12; p = 0.001), smoking (OR: 0.35; 95% CI: 0.01- 0.69; p = 0.038), diabetes mellitus (OR: 0.44; 95% CI: 0.24- 0.68; p = 0.0001) and family history of CAD (OR: 5.51, 95%CI 1.76-17.25; p< 0.00001) were significantly associated with the development of cardiotoxicity. Known history of CAD (OR: 3.72; 95%CI 2.11-6.57; p = 0.0005) was also associated with the development of TIC. On the other hand, obesity (OR: 2.47; 95% CI: 0.93- 6.55; p= 0.07) and hyperlipidaemia (OR: 1.32, 95% CI: 0.71- 2.46; p = 0.38) did not meet statistical significance for association with TIC. Conclusion Identifying women at risk for TIC have several important potential applications. Clinicians may decide to assess LVEF more frequently in patients at highest risk for TIC in order to detect LV systolic dysfunction earlier. Identifying high risk patients may play a role for recognition which individuals would obtain the most benefit from prophylactic therapy for preventing TIC. this could help identify patients who would benefit most from prophylactic therapy for preventing TIC. Finally, these factors could in the future form the basis of a risk model for TIC.