A Study of the Association of the Gut and Tumor Microbiome With Disease and Treatment Outcome of CDK4/6 Inhibitors in Hormone Receptor-positive HER2-negative Breast Cancer
Ciclibiome is a prospective study including BC patients starting treatment with a CDK4/6 inhibitor (in the metastatic and in the adjuvant setting). This study will focus on the interplay between the gut microbiome (its composition and evolution during treatment), circulating immune, metabolic and cytokine biomarkers (before and during treatment), and response outcomes to the CDK4/6 inhibitor. The main aim of the study is to highlight the existence of a microbial, immune and/or metabolic biomarker of response to CDK4/6 inhibition in BC, assessable by a stool or blood sample examination. Ultimately, this will allow to study new potential combination partners for CDK4/6 inhibitors in escalation trials for poor prognosis patients.
⁃ Patients that respond to each of these criteria can be included :
• Diagnosis of previously untreated HR+ HER2- advanced breast cancer (defined as locally advanced and unresectable, or metastatic). HR+ defined as positive estrogen receptors as per local laboratory testing. HER2- defined as negative ISH test or an IHC status of 0 or 1+ as per local laboratory testing.
• Planned first-line treatment with an endocrine therapy (aromatase inhibitor or fulvestrant) and a CDK4/6i.
• Male or female ≥ 18 years of age at the time the informed consent is signed.
• Being able to provide written informed consent.
• Patients with a history of early breast cancer are allowed providing systemic therapy (including adjuvant endocrine therapy) was discontinued more than 6 months ago.
• Patients are willing and able to comply with the protocol for the duration of the study including sample collection.
• Paraffin-embedded tumor tissue available at diagnosis of metastatic disease (inclusion to be discussed if not available).
⁃ Patients that respond to each of these criteria can be included :
• Early HR+ HER2- node-positive breast cancer considered at high risk of relapse (≥ 4 positive lymph nodes, or 1-3 positive lymph nodes and either or both grade 3 or tumor size \> 5 cm). HR+ defined as positive estrogen receptors as per local laboratory testing. HER2- defined as negative ISH test or an IHC status of 0 or 1+ as per local laboratory testing.
• Planned adjuvant treatment with a CDK4/6i, in combination with an endocrine therapy (aromatase inhibitor or tamoxifen, with or without LHRH agonists).
• Male or female ≥ 18 years of age at the time the informed consent is signed.
• Being able to provide written informed consent.
• Patients are willing and able to comply with the protocol for the duration of the study including sample collection.
• Paraffin-embedded tumor tissue available at diagnosis of the disease or at surgical resection (inclusion to be discussed if not available).