Estimation of the Prevalence of HER2 Low and Describe the SoC, Treatment Patterns, and Outcome in Real-world Practice Among Unresectable and/or Metastatic Breast Cancer Patients With HER2 Low Status
Condition: Breast Cancer
MeSH terms: Breast Neoplasms
Study type: Observational

Summary: 
      This is a worldwide, multicenter, non-interventional, retrospective study of patient medical
      records from metastatic breast cancer (mBC) patients previously identified as human epidermal
      growth factor receptor 2 negative (HER2-neg), regardless of hormone status.
    

Detailed description: 
      This is a worldwide, multicenter, non-interventional, retrospective study. The study will
      consist of 2 components. The first component involves local lab rescoring of qualified
      historical HER2 fixed tissue immunohistochemistry (IHC) stained slides (preferably using
      Ventana 4B5 assay) at sites (post-training) for mBC patients previously identified as
      HER2-neg, and independent central retesting of HER2 status using Ventana 4B5 assay for any
      enrolled patients with available archived tissue samples at designated central laboratories.
      Local lab rescoring and independent central retesting/local lab retesting will be conducted
      blinded of historical HER2 IHC scores.

      The second component involves linking the rescored IHC status to the patient medical record
      either through registry databases or patient chart review. Such information will be used to
      describe the patient demographics, histopathological features, clinical presentation, and
      treatment patterns following mBC diagnosis, and clinical outcomes in real-world settings for
      all patients with HER2 scores of 0, >0 and < 1+, and 1+2+/ISH- (HER2 low). The
      clinicopathological and other relevant BC biomarker information will also be examined based
      on historical biomarker testing results and/or new testing conducted as part of this study.
    

Intervention name(s): None (Observational study)
Intervention type(s): Other
Intervention description(s): The data source for this project will be HER2 IHC historical scores, local lab rescoring of historical HER2 fixed tissue slides, independent central retesting or local lab retesting (under special occasions) of HER2 IHC status for enrolled patients who have available tissue, other biomarker testing results based on historical testing and/or testing of archived tissue samples when available, and curated patient-level data. Real-world data sources include electronic health records/electronic medical records (EHR/EMR) and biobank registries. Data from EHR/EMR sources will be curated. Biobank tissue for enrolled patients who have multiple samples available will be selected consecutively when possible and will start with the latest available samples then move backward in time.
Other intervention name(s): Observational study
Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Patients will be eligible for study inclusion if their mBC diagnosis date is between 01
        January 2015 and 31 December 2017 (dating back from 31 December 2017 but no older than 01
        January 2015).
      
Keywords: Metastatic breast cancer; Retrospective study; Epidemiology study; Human epidermal growth factor receptor 2 negative; Human epidermal growth factor receptor 2 low