Blood test may reveal hidden cancer mutations in breast cancer patients

NCT ID NCT06417801

Recruiting now Knowledge-focused Sponsor: AstraZeneca Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Jul 23, 2026 · Updated 4 times

Summary

This study is collecting blood samples from 170 people with metastatic breast cancer to look for ESR1 gene mutations, which can make cancer resistant to hormone therapy. Researchers will compare these blood-based results with standard tissue tests. The goal is to better understand how common these mutations are and when they appear, which could improve future monitoring and treatment strategies.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

What this could lead to: If successful, this could help doctors better understand when and why ESR1 mutations emerge, potentially guiding future treatment decisions.
What could go wrong: This is an observational study, not testing a new treatment. It may not directly improve patient outcomes, and results might not apply to all breast cancer types.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

breast cancer breast carcinoma breast neoplasm

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

METASTATIC BREAST CANCER

Contacts and locations

Locations

Ensino E Terapia de Inovação Clínica Amo - Ética
NOT_YET_RECRUITING

Salvador, Estado de Bahia, 41.950-640, Brazil
Fundação Antonio Prudente - A.C. Camargo Cancer Center
NOT_YET_RECRUITING

São Paulo, 01.509-900, Brazil
Instituto D'Or de Pesquisa E Ensino - São Paulo
NOT_YET_RECRUITING

São Paulo, 01401-002, Brazil
Irmandade Da Santa Casa de Misericórdia de Porto Alegre
NOT_YET_RECRUITING

Porto Alegre, Rio Grande do Sul, 90020-090, Brazil
Research Site
RECRUITING

São Paulo, 04513-020, Brazil
Sociedade Beneficente Israelita Brasileira Hospital Albert Eisntein
NOT_YET_RECRUITING

São Paulo, 05652-000, Brazil

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