The Korean Journal of Clinical Laboratory Science : eISSN 2288-1662 / pISSN 1738-3544

Table 1.

Surrogate definitions of intrinsic subtypes of breast cancer

Intrinsic molecular subtypes Proportion of associated breast cancer (%) Prognosis and clinico-pathological charactestics Patterns of selected genes/proteins expression Molecular diagnosis Therapeutic options Reference
ER PR HER2 Ki-67 Other key genes/proteins
Luminal A 40 Best prognosis, low grade and slow growth High High Neg/low Normal Neg or low CK5/6; Pos CK8/18 IHC Endocrine therapy 12, 37, 39, 40
Luminal B 20 Worse prognosis, tend to grow more quickly than luminal A Positive Normal Variable High Neg or low CK5/6; High AURKA IHC Endocrine, Anti-HER2 and or cytotoxic therapy 12, 37, 39, 40
Her-2 enriched 20∼30 Worse prognosis than both luminals, grows faster Neg/low Neg/low High High Neg or low CK5/6, High GRB7, Low CK5, High mut TP53, PIK3CA IHC or ISH, RTPCR, FISH Anti-HER2 and cytotoxics 12, 39, 40, 43
TNBC 15∼20 More heterogenous than BLBC; and more aggressive than luminals and HER2-enriched Neg/low Neg/low Neg/low High Increased genomic instability: High mutBRCA1, mutTP53, Negative CK5/6 IHC or ISH, RTPCR Chemotherapy 37, 40-42
Basal-like 15 Aggressive tumors with poor prognosis and clinical outcome; presence of distant metastases and high histological grade Neg/low Neg/low Neg/low High High mutBRCA1, mutTP53, mutPIK3CA; High Ki67, EGFR,VEGF, c-Kit; positive CK5/6, CK14,CK17 IHC, ISH, Microarray, RTPCR Chemotherapy: Anthracyclines and Taxanes 37-40
Claudin-low 7∼14 Worse overall survival than luminal A; associated with a low local recurrence rate Neg/low Neg/low Neg/low Variable Low genomic instability; High vimentin, Low claudin3,4,7 and E-Cadherin, integrin a5 IHC, ISH, Microarray, RTPCR Chemotherapy: PARP-inhibitors 12, 37, 40, 41

Abbreviations: ER, estrogen; PR, progesterone; HER2, human epidermal growth factor receptor-2; Ki-67, kiel-67; Neg, negative; CK, cytokeratin; AURKA, aurora kinase A; IHC, immunohistochemistry; GRB7, growth factor receptor bound protein 7; CK, cytokeratin; mut, mutant; TP53, tumor protein 53; PIK3CAs, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; ISH, in situ hybridization; RTPCR, reverse transcription polymerase chain reaction; FISH, fluorescence in situ hybridization; TNBC, triple negative breast cancer; BLBC, basal like breast cancer; BRCA1, breast cancer type 1 susceptibility protein; EGFR, epidermal growth factor receptor; VEGF, vascular endothelial growth factor; c-kit, receptor tyrosine kinase; PARP, poly ADP ribose polymerase.

Korean J Clin Lab Sci 2023;55:121-31
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