Results
A total of 16,375 patients from 15 randomized controlled trials were included for analysis; the pooled incidence of LVEF decline and CHF in dual HER-2 blocked were 4.6% and 0.9%, which was higher than that in anti-HER-2 monotherapy (3.2% and 0.7%, respectively). Dual HER-2 blockade therapy in breast cancer patients significantly increased the risk of developing LVEF decline (OR:1.19, 95%CI: 1.02-1.40,p =0.031) and CHF (OR:1.45, 95%CI: 1.00-2.11, p =0.049) when compared to anti-HER2 monotherapy. Sub-group analysis showed that addition of dual HER-2 blockade to adjuvant treatment for breast cancer significantly increased the risk of developing LVEF decline (p =0.048) and CHF (p= 0.005). In addition, dual HER-2 blockade in breast cancer patients significantly increased the risk of developing LVEF decline (p =0.004) when compared to lapatinib alone, but not for CHF (p =0.11, respectively).