Cyclin-dependent kinase (CDK)4/6 inhibitors in combination with endocrine therapy (ET) are recommended as adjuvant treatment for patients with hormone receptor (HR)-positive/HER2-negative, node-positive early breast cancer at high risk of recurrence. High-risk patients are defined as those with ≥4 positive lymph nodes or 1 to 3 positive lymph nodes with either grade 3 disease or tumor size ≥5 cm (preoperatively or at surgery). This study evaluated the use of CDK4/6 inhibitors plus ET in high-risk, HR-positive/HER2-negative early breast cancer among practices participating in the Integra Connect Quality Initiatives (QI) program compared with those not participating.
Patients aged ≥18 years with HR-positive/HER2-negative early breast cancer at high risk of recurrence were identified using the Integra Connect PrecisionQ real-world deidentified database. The analysis included patients who initiated adjuvant therapy between January 1, 2023, and December 31, 2024, with follow-up through February 28, 2025. Practices were grouped into those participating in the QI program (group A) and those not participating (group B). Group A practices engaged in regular reviews of treatment approaches by care site and provider, with physician roundtable discussions to examine results. Descriptive statistics were used to assess proportions, and chi-square tests were applied to evaluate statistical significance.
Group A included 391 patients, and group B comprised 1320 patients treated with adjuvant therapy. Group A demonstrated higher use of CDK4/6 inhibitors plus ET, with 51% of patients receiving this guideline-recommended combination compared with 42% in group B (P<.01). The use of CDK4/6 inhibitors plus ET was consistently higher in group A across all risk subgroups. Among patients treated with CDK4/6 inhibitors plus ET, abemaciclib was the predominant CDK4/6 inhibitor used in both groups, with 89.7% of group A patients receiving abemaciclib compared with 85.8% in group B. Ribociclib use accounted for 10.3% and 14.2% of CDK4/6 inhibitor–treated patients in group A and group B, respectively.
Participation in the Integra Connect QI program was associated with improved adherence to clinical guidelines for the use of CDK4/6 inhibitors plus ET in HR-positive/HER2-negative early breast cancer patients at high risk of recurrence. These findings highlight the value of quality improvement initiatives in enhancing guideline concordance and optimizing care delivery for high-risk breast cancer patients.
Source: Gorantla V, Choksi R, Kudrik F, et al. Quality initiative for patients with HR+/HER2-, node-positive, early breast cancer at a high risk of recurrence. Presented at: ESMO Congress 2025. October 20, 2025; Berlin, Germany. Abstract 440eP.