Guideline on Hormone Receptor Testing in Breast Cancer and Other Primary Care Providers

Guideline Objective

To improve the quality and accuracy of hormone receptor (HR) testing and its utility as a prognostic and predictive marker for invasive and in situ breast cancer.

Patient Population

Tissue from adult female patients with primary or metastatic invasive or in situ breast cancer was the focus, since most of the literature includes tissue from female patients. However, the recommendations in this guideline would also apply to tissue from male breast cancer patients.

Intended Guideline Users

Personnel involved in HR testing and interpretation and any healthcare provider involved in the management of breast cancer patients.

Research Question(s)

1. Clinical Validity of Immunohistochemistry (IHC): Can IHC reliably determine the levels of expression of the HR pathway and potentially correlate with the clinical outcome compared to other assays (dextran-coated charcoal [DCC] or ligand-binding assay [LBA], enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], and flow cytometry)?
2. Optimizing IHC:
   How should HR testing be performed optimally to assess true HR status? This includes evaluating the effect of the following:
   • Preanalytic variables (i.e., variables of testing involving the collection, fixation, and storage of samples)
   • Analytic variables (i.e., variables associated with the method of testing itself)
   • Thresholds to define results
   • Postanalytic variables (i.e., variables associated with handling of the results, such as reporting)
3. Quality Assurance of IHC:
   What parameters should be used to assess the proficiency of an individual laboratory performing HR-status testing?
4. Clinical Validity of the Oncotype DX Assay:
   Can Oncotype DX reliably determine the levels of expression of the HR pathway?