Trastuzumab-induced cardiotoxicity in breast cancer patients: A meta-analysis and review of the literature (2012-2022).

Abstract

e24101 Background: Breast cancer (BC) is the most common type of cancer diagnosed, and 10-15% of BC patients develop a HER2-positive disease with a poor prognosis. In a previous meta-analysis of NCCTG N9831 and NSABP B-31 trials, treatment of early-stage HER2-positive BC patients with Trastuzumab and chemotherapeutic drugs improved overall survival by 37%. Trastuzumab-induced cardiotoxicity (TIC) is characterized by cardiac dysfunction, including decreased left ventricular ejection fraction (LVEF) and heart failure. Per package inserts, the incidence of TIC is 4-6 times higher than the control. An important risk factor for TIC is the administration of concomitant anthracycline chemotherapy. Several studies have reported that this treatment combination can significantly reduce LVEF compared to Trastuzumab alone. In this study, we compiled recent randomized controlled trials (RCTs) and clinical trial data to evaluate the incidence of cardiotoxicity in Trastuzumab-treated BC and study management guidelines specifically directed for TIC. This will help reduce the morbidity and mortality in these patients. Methods: Our search included PubMed, EMBASE, Web of Science, and Cochrane Library articles from July 2012 through July 2022. RCTs and clinical trials that used Trastuzumab as a therapy and reported its cardiotoxic effects were included. A random-effects model was utilized with Review Manager, and a P value < 0.05 was considered significant. The entire analysis of treatment and control groups had various guideline-directed chemotherapies, including anthracycline-based regimens. Results: Our initial search yielded 26 results. After a full literature review by two independent reviewers, we selected four studies that included 1481 patients with cardiotoxicity data in the treatment and control groups. The analysis pooled from clinical trials showed that the odds of cardiotoxicity (specifically LVEF reduction) in patients treated with Trastuzumab were about seven times higher than the control group (OR 6.78, 95% CI 2.85-16.09, p-value < 0.0001). The guidelines recommend withholding Trastuzumab for ≥ 16% absolute decrease in LVEF from pre-treatment values or an LVEF value below normal institutional limits and ≥ 10% absolute decrease in LVEF from pretreatment values. The safety of continuation or resumption of Trastuzumab in patients with TIC has not been studied, and there are no standardized management guidelines. Conclusions: We conclude in our study that the odds of TIC are increased by almost seven times compared to chemotherapy alone. In addition to just regular monitoring of these patients with history, physical examination, and determination of LVEF by echocardiogram or MUGA scan per protocol, there is a need to formulate guidelines for continuation or resumption of Trastuzumab in patients with TIC.