Managed Care Report Examines Barriers to Breast Cancer Biomarker Testing

Breast cancer is the most commonly diagnosed cancer among U.S. women. Resistance to first-line endocrine therapy is common in hormone receptor-positive, HER2-negative advanced disease. Mutations in ESR1, which encodes estrogen receptor alpha, drive resistance in nearly half of these patients, potentially leaving them on ineffective treatment until imaging detects progression. To explore earlier identification, an AMCP Market Insights Program examines uncertainty surrounding biomarker testing and managed care for ESR1-mutated advanced breast cancer.

The Academy of Managed Care Pharmacy (AMCP; Alexandria, VA, USA) identified evolving biomarker testing and treatment paradigms in its program, “Managed Care Approaches to ESR1-Mutated Advanced Breast Cancer.” The findings focus on monitoring ESR1m before radiologic progression using circulating tumor DNA (ctDNA) liquid biopsy. This approach can enable earlier switching to effective therapy and timely treatment adjustment to extend time on first-line therapy.

The program found that uncertainty around optimal testing parameters is contributing to inconsistent testing practices. AMCP also cited coverage friction across medical and pharmacy benefits and care delays as challenges affecting biomarker testing pathways. Payers were described as weighing earlier detection against a growing class of targeted therapies.

AMCP outlined opportunities for payers to address these gaps through flexible, evidence-based treatment pathways. Recommendations included aligning coverage policies across benefits and streamlining prior authorization through auto-approvals for guideline-concordant testing, extended authorization durations, and gold carding. Payers also emphasized the need for total cost-of-care analyses that consider delayed progression rather than testing costs alone.

The program was independently conducted with funding support from AstraZeneca. The full peer-reviewed Market Insight supplement was published in the October 2026 edition of the Journal of Managed Care & Specialty Pharmacy. AMCP stated that improved support for community oncologists, patient shared decision-making, and multi-stakeholder alignment may help promote testing consistency as next-generation selective estrogen receptor degraders move into earlier treatment lines.

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