Update to ASCO/CAP Guideline on ER and PgR Testing in Breast Cancer

On Jan. 13, an updated guideline for estrogen and progesterone receptor (ER/PgR) testing in breast cancer was released jointly by the College of American Pathologists (CAP) and the American Society of Clinical Oncology (ASCO). The updated guideline reaffirms much of the original guidance and includes more specific recommendations for handling and reporting cases with low ER expression. The updated guideline was posted as online early release to the Archives of Pathology & Laboratory Medicine (Jan. 13, 2020, doi: 10.5858/arpa.2019-0904-SA).

A CAP press release highlights the following changes:
"Cases with 1-10% of cells staining for ER expression will now be reported as ER-low positive. Pathology reports for these cases should include a recommended comment that acknowledges the more limited data on endocrine responsiveness in this group. Also in such cases, pathologists should report the status of internal controls, with a special comment for specimens that lack internal positive controls."

The CAP press release also notes that the new guideline more clearly recommends that:
". . . ER be tested in cases of newly diagnosed DCIS (without invasion) to help estimate potential benefit of endocrine therapy to reduce the risk of a future breast cancer event. But, specifically, PgR testing in DCIS is optional."

Read the CAP press release.
Access the updated Estrogen and Progesterone Receptor Testing in Breast Cancer guideline.

Posted 1/14/2020