8
Diagnosis
HER2-positive Breast Cancer or TNBC
Oncotype DX, EndoPredict, MammaPrint, BCI, Prosigna,
Ki67, or IHC4
Recommendation 1.27
➤ If a patient has HER2-positive breast cancer or TNBC, the clinician
should NOT use multiparameter gene expression or protein assays
(Oncotype DX, EndoPredict, MammaPrint, BCI, Prosigna, Ki67, or
IHC4) to guide decisions for adjuvant endocrine and chemotherapy.
(Strong recommendation; IC-Ins)
Emerging Biomarkers
Tumor-Infiltrating Lymphocytes (TILs)
Recommendation 1.28
➤ If a patient has node-negative or node-positive ER-positive, HER2-
positive, or TNBC, the clinician should NOT use TILs test to guide
decisions for (neo)adjuvant endocrine and chemotherapy. (Strong
recommendation; IC-Ins)
PD-L1 Testing
Recommendation 1.29
➤ If a patient has node-negative or node-positive ER-positive, HER2-
positive, or TNBC, the clinician should NOT use PD-L1 testing to
guide decisions for (neo)adjuvant endocrine and chemotherapy.
(Strong recommendation; EB-H)
Circulating Tumor Cells (CTC)
Recommendation 1.30
➤ If a patient has node-negative or node-positive ER-positive, HER2-
positive, or TNBC, the clinician should NOT use CTC test to guide
decisions for adjuvant endocrine and chemotherapy. (Strong
recommendation; EB-I)
Circulating Tumor DNA (ctDNA)
Recommendation 1.31
➤ If a patient has node-negative or node-positive ER-positive, HER2-
positive, or TNBC, the clinician should NOT use ctDNA test to
guide decisions for adjuvant endocrine and chemotherapy. (Strong
recommendation; EB-I)
