Vascular Inflammation and Cardiovascular Burden in Metastatic Breast Cancer Female Patients Receiving Hormonal Treatment and CDK 4/6 Inhibitors or Everolimus

Cardiovascular complications of ribociclib in breast cancer patients

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have unprecedentedly advanced hormone-dependent breast cancer treatment paradigm. In the metastatic setting, ribociclib has consistently demonstrated survival benefit in pre-, peri-, and postmenopausal patients, conjugating efficacy with health-related quality of life preservation. Accordingly, the emergence of cardiac and/or vascular adverse events related to this novel targeted agent is gaining significant interest. This narrative review provides an overview of the incidence and spectrum of cardiovascular toxicity, in both clinical trial framework and real-world evidence. The potential pathogenetic mechanism, along with the available diagnostic parameters including biomarkers, and proper management, are also summarized.

CDK4/6 inhibitors: basics, pros, and major cons in breast cancer treatment with specific regard to cardiotoxicity - a narrative review

Breast cancer is characterized by the uncontrolled proliferation of breast cells, with a high incidence reported in 2020 to have affected over 2 million women. In recent years, the conventional methods of treating breast cancer have involved radiotherapy and chemotherapy. However, the emergence of CDK4/6 inhibitors has shown potential as a promising cancer therapy. Cyclin-dependent kinases (CDK) inhibitors are a class of molecules that impede the formation of an active kinase complex, thereby hindering its activity and consequently halting the progression of the cell cycle. It was discovered that they have a significant impact on impeding the progression of the cancer. This is evident with the Food and Drug Administration's approval of drugs such as palbociclib, ribociclib, and abemaciclib for hormone receptor-positive metastatic breast cancer in combination with specific endocrine therapies. In spite of enormous success in breast cancer treatment, certain obstacles have emerged, such as therapy resistance, side effects, and most of all, cardiotoxicity. Some of these drawbacks have been successfully overcome by dosage reduction, different combinations of the drugs, and the assessment of each patient's condition and suitability prior to treatment. Yet other drawbacks still require tenacious research, especially certain cases of cardiotoxicities. This article delves into the biological mechanisms of CDK4/6 in the cell cycle and cancer, as well as the clinical advantages and most common adverse events (AEs) associated with CDK4/6 inhibitors. The primary objective of this review is to provide a comprehensive analysis of cardiotoxic AEs and elucidate the underlying pathophysiological mechanisms responsible for the cardiotoxicity of CDK4/6 inhibitors.

Adverse Cardiovascular Events Associated With Cyclin-Dependent Kinase 4/6 Inhibitors in Patients With Metastatic Breast Cancer

Background Cyclin-dependent kinase (CDK) 4 and 6 inhibitors have significantly improved survival in patients with hormone receptor-positive metastatic breast cancer. There are few data regarding the epidemiology of cardiovascular adverse events (CVAEs) with these therapies. Methods and Results Using the OneFlorida Data Trust, adult patients without prior cardiovascular disease who received at least 1 CDK4/6 inhibitor were included in the analysis. CVAEs identified from International Classification of Diseases, Ninth and Tenth Revisions (ICD-9/10) codes included hypertension, atrial fibrillation(AF)/atrial flutter (AFL), heart failure/cardiomyopathy, ischemic heart disease, and pericardial disease. Competing risk analysis (Fine-Gray model) was used to determine the association between CDK4/6 inhibitor therapy and incident CVAEs. The effect of CVAEs on all-cause death was studied using Cox proportional hazard models. Propensity-weight analyses were performed to compare these patients to a cohort of patients treated with anthracyclines. A total of 1376 patients treated with CDK4/6 inhibitors were included in the analysis. CVAEs occurred in 24% (35.9 per 100 person-years). CVAEs were slightly higher in patients who received CKD4/6 inhibitors compared with anthracyclines (P=0.063), with higher death rate associated with the development of AF/AFL or cardiomyopathy/heart failure in the CDK4/6 group. The development of cardiomyopathy/heart failure and AF/AFL was associated with increased all-cause death (adjusted hazard ratio [HR], 4.89 [95% CI, 2.98-8.05]; and 5.88 [95% CI, 3.56-9.73], respectively). Conclusions CVAEs may be more common with CDK4/6 inhibitors than previously recognized, with increased death rates in these patients who develop AF/AFL or heart failure. Further research is needed to definitively determine cardiovascular risk associated with these novel anticancer treatments.

Elevated transaminases and development of cardiomyopathy in a 32-year-old woman with metastatic breast cancer after treatment with ribociclib followed by palbociclib

INTRODUCTION

Cyclin-dependent kinase 4 and 6 inhibitors, ribociclib and palbociclib, are associated with reports of transaminitis and adverse cardiac events.

CASE REPORT

The patient is a previously healthy 32-year-old female diagnosed with estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor 2 negative metastatic breast cancer. From July to September 2021, the patient was initiated on ribociclib followed by palbociclib for metastatic breast cancer. She subsequently experienced two episodes of transaminitis and was diagnosed with cardiomyopathy.

MANAGEMENT AND OUTCOME

The patient experienced transaminitis 2 weeks after the initiation of ribociclib resulting in discontinuation. When rechallenged with palbociclib, the patient experienced transaminitis within 1 week of initiation, which resulted in discontinuation. Approximately 1 month after palbociclib discontinuation, the patient was diagnosed with congestive heart failure with a left ventricular ejection fraction of 24%.

DISCUSSION

To our knowledge, there are few case studies investigating cyclin-dependent kinase 4 and 6 inhibitor rechallenge following transaminitis. Prior literature suggests that transaminitis with cyclin-dependent kinase 4 and 6 inhibitors is not a class effect, but this case report suggests otherwise. This report presents a rare case of cardiomyopathy and transaminitis following the administration of cyclin-dependent kinase 4 and 6 inhibitors, ribociclib and palbociclib.