Assessing Thrombotic Risk in Patients with HR+/HER2- Breast Cancer Receiving CDK4/6 Inhibitors: Insights from...

Area of Science:

• Oncology
• Pharmacology
• Cardiovascular Medicine

Background:

• Hormone receptor-positive, HER2-negative (HR+/HER2-) breast cancer is the most common subtype.
• Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors (palbociclib, ribociclib, abemaciclib) are crucial for advanced HR+/HER2- breast cancer.
• CDK4/6 inhibitors may elevate the risk of thrombotic events, including venous thromboembolism (VTE).

Purpose of the Study:

• To evaluate the incidence of thrombotic events in patients with HR+/HER2- breast cancer treated with CDK4/6 inhibitors in a real-world setting.
• To compare the risk of thrombosis associated with different CDK4/6 inhibitors.
• To identify factors influencing thrombosis risk in this patient population.

Main Methods:

• Retrospective study analyzing data from 447 patients treated with CDK4/6 inhibitors between 2016 and 2023.
• Inclusion criteria: early-stage, high-risk breast cancer patients receiving abemaciclib for at least one month.
• Primary outcomes: incidence of VTE and arterial thrombosis.

Main Results:

• A total of 447 patients were included; 11.8% experienced thrombotic events (37.7% pulmonary embolism, 18.8% symptomatic deep vein thrombosis).
• Patients with a prior VTE history had a significantly higher thrombosis risk (p=0.03).
• Abemaciclib was associated with a higher incidence of thrombosis (16.3%) compared to palbociclib (10.2%).

Conclusions:

• The incidence of thrombotic events in real-world settings exceeds clinical trial data.
• Risk assessment and potential thromboprophylaxis are crucial for patients on CDK4/6 inhibitors.
• Further research is needed to develop risk assessment tools for predicting thrombosis in these patients.