Clinical impact of interruption in adjuvant Trastuzumab therapy in patients with operable HER-2 positive breast cancer

Real-world data of cardio-oncologic interventions for cardiovascular adverse events with oral oncolytics

BACKGROUND

Oral cancer therapy-related cardiovascular (CV) toxicity has a wide variety of presentations including arrhythmia, cardiomyopathy, and myocardial infarction, but clinical evidence related to its management is limited. The purpose of this IRB-approved, single-center, retrospective, cohort study was to characterize cardio-oncologic interventions for CV adverse events related to oral oncolytics.

METHODS

The cohort included 67 patients who were admitted to a multi-hospital health system between June 1, 2016 and July 31, 2021, had at least one medical record order of oral oncolytics considered to have cardiotoxic potential, and had an ICD10 code for a cardiotoxic event added to their electronic medical records after initiation of oral oncolytics.

RESULTS

The majority (97%) had pre-existing cardiovascular disease (CVD) or a CV risk factor. The three most common classes of oral oncolytics were aromatase inhibitors (36%), BCR-ABL inhibitors (16%), and VEGFR inhibitors (13%). New-onset or worsening heart failure (HF) (n = 31), which occurred after a median of 148 days (Interquartile range (IQR) 43-476 days) was the most common cardiotoxic event. The most frequent interventions were pharmacological treatment of the CV adverse event (n = 44) and treatment interruption (n = 18), but guideline-directed medication therapy for HF could be further optimized.

CONCLUSION

Pre-existing CVD or CV risk factors predispose oncology patients to CV adverse events. Real-world practice reveals that CV adverse events require temporary interruption of treatment and initiation of pharmacologic treatment. A multidisciplinary, patient-centered approach that includes discussion of risks/benefits of treatment continuation, and initiation of guideline-directed treatment is recommended until high-quality, drug-specific data for monitoring and treatment become available.

Adjuvant Trastuzumab Emtansine Versus Paclitaxel and Trastuzumab in Stage I HER2-Positive Breast Cancer: The ATEMPT Trial

This ASO perspective reviews the findings of a randomized, phase II clinical trial evaluating adjuvant trastuzumab emtansine (T-DM1) compared with paclitaxel and trastuzumab (TH) in stage I human epidermal growth factor receptor 2-positive breast cancer, as reported recently by the ATEMPT trial investigators. Patients treated with T-DM1 had better disease-free survival but did not have fewer treatment toxicities. The T-DM1-treated group had higher rates of treatment discontinuations, therefore long-term follow-up will be required to evaluate survival differences between T-DM1 and TH.

Three-Year Outcomes Following Permissive Cardiotoxicity in Patients on Trastuzumab

INTRODUCTION

Cardiotoxicity, manifest by reduced left ventricular ejection fraction (LVEF), is the most common reason for the premature discontinuation of trastuzumab. While permissive cardiotoxicity (where mild cardiotoxicity is accepted to enable ongoing trastuzumab) has been shown feasible, the longer-term outcomes are unknown. We aimed to study the intermediate-term clinical outcomes of patients who underwent permissive cardiotoxicity.

MATERIALS AND METHODS

We performed a retrospective cohort study of patients referred to the cardio-oncology service at McMaster University from 2016 to 2021 for LV dysfunction following trastuzumab administration.

RESULTS

Fifty-one patients underwent permissive cardiotoxicity. The median (25th-75th percentile) follow-up time from cardiotoxicity onset was 3 years (1.3-4 years). Forty-seven (92%) patients completed trastuzumab; 3 (6%) developed severe LV dysfunction or clinical heart failure (HF) while on trastuzumab and prematurely discontinued therapy. One discontinued trastuzumab by patient choice. At final follow-up after therapy completion, 7 (14%) patients still had mild cardiotoxicity, including 2 who had clinical heart failure and stopped trastuzumab early. Among those with recovered LV function, 50% had normalized LVEF or GLS by 6 and 3 months, respectively, after initial cardiotoxicity. There was no difference in characteristics between those who did or did not recover their LV function.

CONCLUSIONS

Among patients exposed to permissive trastuzumab cardiotoxicity for HER2-positive breast cancer, 6% were unable to complete planned trastuzumab due to severe LV dysfunction or clinical HF. Although most patients recover their LV function after trastuzumab discontinuation or completion, 14% still have persistent cardiotoxicity by 3-year follow-up.

Monocyte-to-lymphocyte ratio as predictor of cancer therapy-related cardiotoxicity in patients with breast cancer: a pilot cohort study

BACKGROUND

Elevated pre-treatment baseline inflammation has been associated with cancer therapy-related cardiac dysfunction (CTRCD) in patients with breast cancer. Monocyte-to-lymphocyte ratio (MLR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio and systemic immune-inflammation index (NLR × platelets) have emerged in clinical context as markers of disease-related inflammation.

OBJECTIVES

To evaluate development of CTRCD according to pre-treatment blood inflammatory biomarkers in patients with breast cancer.

METHODS

Pilot cohort study including consecutive female patients ≥ 18 years with HER2-positive early breast cancer who consulted at the institution's breast oncology outpatient clinic between march/2019 and march/2022. CTRCD: absolute reduction in LVEF > 10% to below 53% (2D-echocardiogram). Survival analysis was performed using Kaplan-Meier curves, compared by the log-rank test, and discrimination ability was evaluated through AUC-ROC.

RESULTS

Forty-nine patients (53.3 ± 13.3 y) were included and followed-up for a median of 13.2 months. CTRCD was observed in 6 (12.2%) patients. Patients with high blood inflammatory biomarkers had lower CTRCD-free survival (P < 0.050 for all). MLR showed statistically significant AUC (0.802; P = 0.017). CTRCD was observed in 27.8% of patients with high MLR versus 3.2% with low MLR (P = 0.020); negative predictive value was 96.8% (95%CI 83.3-99.4%).

CONCLUSION

In patients with breast cancer, elevated pre-treatment inflammatory markers were associated with increased risk of cardiotoxicity. Among these markers, MLR had good discriminatory performance and high negative predictive value. The incorporation of MLR might improve risk evaluation and selection of patients for follow-up during cancer therapy.

Mechanisms of trastuzumab induced cardiotoxicity - is exercise a potential treatment?

The use of the adjuvant therapeutic antibody trastuzumab in breast cancer is associated with a range of cardiotoxic side effects despite successfully reducing the severity of outcomes cancer patients,. The most common cardiac effect, a reduction in left ventricular ejection fraction (LVEF), is a known precursor to heart failure and often requires interruption of chemotherapy to avoid endangering patients further. An understanding of trastuzumab's cardiac-specific interactions is therefore critical in devising new methods to not only avoid permanent cardiac damage, but also prolong treatment time, and therefore effectiveness, for breast cancer patients. Increasingly, the use of exercise as a treatment has been indicated across the field of cardio-oncology due to encouraging evidence that it can protect against LVEF reductions and heart failure. This review explores the mechanisms of trastuzumab-mediated cardiotoxicity, as well as the physiological effects of exercise on the heart, in order to assess the suitability of exercise intervention for breast cancer patients on trastuzumab antibody-therapy. We furthermore draw comparison to existing evidence for exercise intervention as a cardioprotective treatment in doxorubicin-induced cardiotoxicity. Although preclinical evidence seems to support exercise-based approaches also in trastuzumab-cardiotoxicity, current clinical evidence is too limited to confidently recommend it as a treatment, largely owing to issues of adherence. Future studies should therefore examine how the variety and duration of exercise can be adjusted to improve treatment effectiveness at a more personalised level.

Herceptin-Mediated Cardiotoxicity: Assessment by Cardiovascular Magnetic Resonance

Herceptin (trastuzumab) is a recombinant, humanized, monoclonal antibody that targets the human epidermal growth factor receptor 2 (HER2) and is used in the treatment of HER2-positive breast and gastric cancers. However, it carries a risk of cardiotoxicity, manifesting as left ventricular (LV) systolic dysfunction, conventionally assessed for by transthoracic echocardiography. Clinical surveillance of cardiac function and discontinuation of trastuzumab at an early stage of LV systolic dysfunction allow for the timely initiation of heart failure drug therapies that can result in the rapid recovery of cardiac function in most patients. Often considered the reference standard for the noninvasive assessment of cardiac volume and function, cardiac magnetic resonance (CMR) imaging has superior reproducibility and accuracy compared to other noninvasive imaging modalities. However, due to limited availability, it is not routinely used in the serial assessment of cardiac function in patients receiving trastuzumab. In this article, we review the diagnostic and prognostic role of CMR in trastuzumab-mediated cardiotoxicity.

Long-term follow-up assessment of cardiac safety in SAFE-HEaRt, a clinical trial evaluating the use of HER2-targeted therapies in patients with breast cancer and compromised heart function

PURPOSE

HER2-targeted therapies are associated with cardiotoxicity which is usually asymptomatic and reversible. We report the updated cardiac safety assessment of patients with compromised heart function receiving HER2-targeted therapy for breast cancer, enrolled in the SAFE-HEaRt trial, at a median follow-up of 3.5 years.

METHODS

Thirty patients with stage I-IV HER2-positive breast cancer receiving trastuzumab with or without pertuzumab, or ado-trastuzumab emtansine (T-DM1), with asymptomatic LVEF (left ventricular ejection fraction) 40-49%, were started on cardioprotective medications, with the primary endpoint being completion of HER2-targeted therapy without cardiac events (CE) or protocol-defined asymptomatic worsening of LVEF. IRB-approved follow-up assessment included 23 patients.

RESULTS

Median follow-up as of June 2020 is 42 months. The study met its primary endpoint with 27 patients (90%) completing their HER2-targeted therapies without cardiac issues. Of the 23 evaluable patients at long-term f/u, 14 had early stage breast cancer, and 9 had metastatic disease, 8 of whom remained on HER2-targeted therapies. One patient developed symptomatic heart failure with no change in LVEF. There were no cardiac deaths. The mean LVEF improved to 52.1% from 44.9% at study baseline, including patients who remained on HER2-targeted therapy, and those who received prior anthracyclines.

CONCLUSIONS

Long-term follow-up of the SAFE-HEaRt study continues to provide safety data of HER2-targeted therapy use in patients with compromised heart function. The late development of cardiac dysfunction is uncommon and continued multi-disciplinary oncologic and cardiac care of patients is vital for improved patient outcomes.