Breast carcinomas expressing basal markers have poor clinical outcome regardless of estrogen receptor status.
To evaluate the clinical significance of gene expression-based classification and define the characteristic features of the new basal-like subtype, invasive breast carcinomas were divided into ER, HER2, basal-like and null subtypes by immunohistochemical analysis. A total of 401 invasive breast carcinomas were submitted to tissue microarray and stained with ER, HER2, EGFR, c-KIT and cytokeratin (CK) 5/6. The basal-like tumors, defined as positive for one or more basal markers but negative for both ER and HER2, comprised 18.5%. They were larger (p=0.041), showed higher grade (p<0.001), and more frequently expressed p53 (p=0.003). Expression of the basal marker itself showed negative prognostic effect, particularly in node-positive group. Even ER-positive patients had far shorter disease-free survival (DFS) when the tumor coexpressed one or more basal marker (p<0.001). Discrimination of basal-like subtype or tumors positive for basal markers may be clinically significant also in the treatment and prognosis of breast carcinomas.
Shin
Bong Kyung
BK
Department of Pathology, Korea University Guro Hospital, Seoul 152-703, Korea.
Lee
Youngseok
Y
Lee
Jung Bok
JB
Kim
Han Kyeom
HK
Lee
Jae Bok
JB
Cho
Su Jin
SJ
Kim
Aeree
A
D014408:Biomarkers, Tumor / Q000032:analysis* / Q000378:metabolism; D001943:Breast Neoplasms / Q000145:classification* / Q000175:diagnosis* / Q000473:pathology; D002277:Carcinoma / Q000145:classification* / Q000175:diagnosis* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000145:classification / Q000473:pathology; D018276:Carcinoma, Medullary / Q000145:classification; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D011379:Prognosis; D011960:Receptors, Estrogen / Q000032:analysis*
D014408:Biomarkers, Tumor; D011960:Receptors, Estrogen