Objective Adjuvant chemotherapy with trastuzumab improves the postoperative life expectancy of women with early-stage breast cancer. Although trastuzumab is reportedly cardiotoxic, quantification based on real-world evidence is lacking. Therefore, in this study, we aimed to analyse trastuzumab cardiotoxicity using a nationwide claim-based database. Methods In this retrospective study, we used data from a nationwide claims database (Japan Medical Data Center, Tokyo, Japan) under the universal healthcare system. Women with breast cancer who underwent initial surgery were included. Patients with recurrent or advanced-stage breast cancer, with a history of heart failure, receiving neoadjuvant chemotherapy or a preoperative history of less than 6 months were excluded. Propensity score (PS) was calculated using logistic regression based on age, cardiovascular risk factors, radiotherapy and concomitant anthracyclines (AC). Results We identified 12 060 eligible patients (mean age 50.8±8.56 years) between January 2010 and December 2019. After 1:2 PS matching (trastuzumab users, TZ, n=1005; non-users, NT, n=2010), Cox proportional hazards model analysis showed that the rate of heart failure development within 18 months postoperative was significantly higher in the TZ group than in the NT group (adjusted HR 2.28, 95% CI 1.38 to 3.77). Baseline cardiac evaluation in the combined AC/TZ cases was 27.2% preoperative, 66.0% pre-AC and 86.6% pre-TZ, respectively. Conclusion Trastuzumab cardiotoxicity remained relevant in the claim-based analysis adjusted for AC effects. Further collaborative studies in cardio-oncology with real-world data are warranted to improve the rate of baseline cardiovascular risk assessment in patients with cancer scheduled for cardiotoxic cancer treatment.

We have produced 14 monoclonal antibodies to inducible nitric oxide synthase purified from rat peritoneal cytotoxic activated macrophages. None of the antibodies showed neutralizing activity, but some of them enhanced the enzyme activity through stabilization of the enzyme.

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.