Estrogen and Progesterone Receptor Testing in Breast Cancer
Key Points
Key Points
A well-performed ER/PgR assay identifies which patients could benefit from to endocrine therapy as treatment after a diagnosis of breast cancer. Additionally, hormone receptor status can be valuable more broadly for tumor classification and other factors that inform treatment.
Globally, more than 1 million women are being diagnosed annually with breast cancer and receptor testing conducted on these biopsies typically discern that approximately 8 in 10 of these women have ER positive breast cancer.
The new guidance reaffirms many of the 2010 recommendations, including that patients with breast cancers having 1–100% ER expression be considered ER positive for the purpose of endocrine therapy decisions. However, new reporting recommendations are made for cases with 1–10% ER expression to acknowledge the more limited data on endocrine responsiveness in this group and overlapping features with ER negative cancers.
The update also has a new recommendation for labs to establish a specific standard operating procedure to ensure the validity of low positive (1–10%) or negative (0 or <1%) interpretations and results. Correlation of ER staining with the histologic features (as well as attention to other standard quality control measures) is also recommended and unusual/discordant results worked up.
The utility of PgR-positive population, but testing using similar principles to ER testing is still recommended for invasive cancers.
Additionally, the updated draft now recommends ER testing for patients diagnosed with ductal carcinoma in situ, but PgR testing is optional.
Diagnosis
Diagnosis
...algorithm for ER/PgR testingSamples with 1...
...sting conditions (no change)Large, (preferably...
...ssue handling requirements (no chan...
...ernal validation procedures (change anticipated)T...
...QA proceduresOngoing quality control and e...
...l proficiency assessmentThe laborator...
...mal laboratory accreditationOn-site...
...es should include ongoing quality co...
...tation of any ER result should include e...
...uld establish and follow a standard oper...
...s of internal controls should be reported...
...dated IHC is the recommended standard test for pre...
...testing in cases of newly diagnosed DCIS (w...
...ive Breast Cancer Histopathologic Concordance with...
...nal Recommended Reporting Comments for...
...ommendations for Scoring (Readout) and Interp...
...Case examples to illustrate stain intensit...
...gure legend: Examples of invasive cancers...
...ternal ControlsFigure legend: Examples of int...
...rnal ControlsFigure legend: Optimal external (ide...