6
Diagnosis
Ki67
Recommendation 1.19
➤ If a patient is postmenopausal and has stage I–II breast cancer, the
clinician may use Ki67 expression in conjunction with other clinical
and pathologic parameters to guide decisions on adjuvant endocrine
and chemotherapy when multigene assays are not available. Ki67
expression levels are most informative for prognosis when the level
is <5% (low proliferation) or >30% (high proliferation) because
technical reliability of distinguishing values within this range is
limited. (Moderate recommendation; EB-I)
Recommendation 1.20
➤ If a patient is postmenopausal and has breast cancer, there is
insufficient evidence to use baseline Ki67 expression or Ki67 level
after 2 weeks of neoadjuvant aromatase inhibitor (AI) therapy to
guide decisions on adjuvant endocrine and chemotherapy. (Weak
recommendation; IC-L)
Recommendation 1.21
➤ Despite the limitations associated with Ki67 testing, a patient with
node-positive breast cancer with a high risk of recurrence and a
Ki67 score of ≥20% as determined by an FDA-approved test may be
offered two years of abemaciclib plus endocrine therapy. (Strong
recommendation; EB-I)
Immunohistochemistry 4 (IHC4)
Recommendation 1.22
➤ If a patient has node-negative or node-positive breast cancer with
1–3 positive nodes, the clinician may use IHC4 test to guide decisions
for adjuvant endocrine and chemotherapy if the assay has been
validated in the performing laboratory and if multigene assays are not
available. (Moderate recommendation; EB-I)
uPA and PAI-1
➤ If a patient has ER-positive, HER2-negative (node-negative) breast
cancer, the clinician may use the uPA and PAI-1 to guide decisions
about adjuvant endocrine and chemotherapy. (Weak recommendation;
EB-H)
➤ If a patient has HER2-positive breast cancer or triple-negative breast
cancer (TNBC), the clinician should NOT use the uPA and PAI-1 to
guide decisions about adjuvant endocrine and chemotherapy. (Weak
recommendation; IC-Ins)
