5
Recommendation 2.2
➤ Interpretation of any ER result should include evaluation of the
concordance with the histologic findings of each case. Clinicians
should also be aware of when results are highly unusual/discordant
and work with pathologists to attempt to resolve or explain atypical
reported findings (see Table 1 as an aid in this process). (Strong
Recommendation; IC-H)
Recommendation 2.3
➤ Laboratories should establish and follow a standard operating
procedure (SOP) stating the steps the lab takes to confirm or
adjudicate ER results for cases with weak stain intensity or ≤10%
of cells staining (see Figure 1 for an example SOP). (Strong
Recommendation; IC-H)
Recommendation 2.4
➤ The status of internal controls should be reported for cases with
0-10% staining. For cases with these results without internal controls
present and with positive external controls, an additional report
comment is recommended (see Table 2). (Strong Recommendation;
IC-H)
Recommendation 3
➤ Validated IHC is the recommended standard test for predicting
benefit from endocrine therapy. No other assay types are
recommended as the primary screening test for this purpose. (Strong
Recommendation; EB-H)
Recommendation 4
➤ ER testing in cases of newly diagnosed DCIS (without associated
invasion) is recommended to determine potential benefit of endocrine
therapies to reduce risk of future breast cancer. PgR testing is
considered optional. (Moderate Recommendation; EB-I)
