Treatment Landscape in Early-Stage HR+/HER2- Breast Cancer

Disease Burden & Stage Distribution

Across all countries, the majority of patients were reported to have early-stage disease (84.7%), while 15.3% were in the metastatic setting. On average, clinicians reported managing 211.5 (± 72.7) breast cancer patients, of whom a mean of 61.9 (± 13.3) were identified as having HR+/HER2- breast cancer.

Nodal Risk Segmentation

Among premenopausal patients, 67.2% were N0, while 25.2% had N1 and 7.6% had N2+ nodal involvement. In comparison, a higher proportion of postmenopausal patients were node-negative (76.6%), while 17.8% had N1 and 5.5% had N2+ nodal involvement.

Neoadjuvant Decision Patterns

Among premenopausal women, the use of neoadjuvant chemotherapy increased with greater nodal involvement — 42.3% of N0 patients, 61.6% of N1 patients, and 57.6% of N2+ patients received neoadjuvant chemotherapy. In postmenopausal women, the proportion of patients receiving neoadjuvant chemotherapy was generally lower, particularly among N0 patients (20.7%).

Adjuvant Treatment Intensification

Among N0 patients, the majority received endocrine therapy alone (72.6%), reflecting lower recurrence risk in this group. As the number of involved lymph nodes increased, the treatment pattern shifted toward more intensive therapy. In N2+ patients, approximately half (50.3%) received combined chemotherapy and endocrine therapy.

Endocrine Strategy by Menopausal Status

In premenopausal N2+ patients, abemaciclib + AIs ± an LHRH agonist accounted for the largest share (51.3%). In postmenopausal N2+ patients, AIs ± an LHRH agonist accounted for 47% of the treatment share, closely followed by abemaciclib + AIs ± an LHRH agonist (42.7%).

CDK4/6 Adoption Signals

The survey showed increased use of abemaciclib in patients with ≥4 positive nodes, aligning with findings from the monarchE trial, which demonstrated improved invasive disease-free survival with adjuvant abemaciclib plus endocrine therapy in high-risk, node-positive HR+/HER2− breast cancer. Country-level variation was observed, with the use of abemaciclib + AIs ± an LHRH agonist highest in Germany (59.3%) and lowest in Japan (35.7%).

Market Variation

Country-level variation was observed across Italy, Germany, the United Kingdom, Japan, and China, with lower neoadjuvant utilization rates in Japan and China, while Italy and Germany reported comparatively higher use. Japan demonstrated a distinctly different adjuvant pattern, with treatment approaches more evenly distributed across categories compared with other participating countries.

Strategic Implications

The CDK4/6 inhibitor class is expected to remain highly competitive, with differentiation driven by efficacy in high-risk populations, safety profiles, and treatment convenience. Oral SERDs and ADCs represent key growth opportunities, particularly if supported by robust survival data and clearly defined positioning within treatment algorithms. Significant opportunities exist in addressing unmet needs such as overcoming endocrine resistance, reducing long-term recurrence risk, and identifying predictive biomarkers to enable personalized treatment.