Background: The prognosis of cancer survivors has dramatically improved, but effective strategies for cancer treatment-related cardiovascular disorders (CTRCD) remain to be elucidated in the emerging field of cardio-oncology. In this study, we investigated risk factors for CTRCD in breast cancer patients treated with trastuzumab. Methods and Results: We performed a retrospective analysis of 141 consecutive women who received adjuvant trastuzumab, and underwent baseline (BL) and follow-up (FU) echocardiography at Juntendo University between April 2010 and December 2016. The major concomitant treatment was anthracyclines in 94% and radiotherapy in 53%. During the median treatment period of 11 months, there were 22 (15.6%) cardiology consultations, 3 (2.1%) treatment interruptions with irreversible CTRCD, and no deaths. Left ventricular ejection fraction (LVEF) was decreased from a median 67.5% (BL) to 63.4% (FU; P<0.0001), with reduced LVEF noted in 26.2% at FU<90%BL, in 13.5% at FU<BL-10%, and in 5.7% at LVEFFU <53%. A significantly greater percentage of patients with CTRCD (FU<BL-10% and LVEFFU <53%) had cardiovascular risk factors (CVRF; 42.9% vs. 8.2%, P=0.02). On multivariable analysis, CVRF were also significantly associated with CTRCD (OR, 11.96; 95% CI: 1.30-110.34). Conclusions: Adjuvant trastuzumab for early-stage breast cancer was associated with reduced LVEF; and CVRF were an independent predictor for CTRCD. The concomitant effect of anthracyclines should not be underestimated, even at lower doses.
Keywords: Breast cancer; Cancer treatment-related cardiovascular disorder; Cardio-oncology; Cardiovascular risk factor; Trastuzumab.
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