Immunohistochemical heterogeneity of breast carcinomas negative for estrogen receptors, progesterone receptors and Her2/neu (basal-like breast carcinomas).
Basal breast carcinomas triple negative for estrogen receptors, progesterone receptors and Her2/neu breast carcinomas are more aggressive than conventional neoplasms. We studied 64 cases with immunohistochemistry, using 23 antibodies, to characterize diverse pathological pathways. A basal cytokeratin was identified in 81% of tumors and vimentin was identified in 55%. The mean Ki67 index was 46% (range, 10-90%). Coincident expression of p50 and p65, which suggests an active nuclear factor-kappaB factor, was present in 13% of neoplasms. Epithelial growth factor receptor (EGFR), insulin-like growth factor-I receptor (IGF-IR) or c-kit (CD117) was identified in 77% of tumors. Loss of protein tyrosine phosphatase was found in 14%, whereas Akt activation was present in 28%. Several differences were identified between two subtypes of basal breast carcinomas: the pure variant (negative S-100 and actin) was more frequently associated with 'in situ carcinoma' (P=0.019) and pBad overexpression (P=0.098), whereas the myoepithelial variant (positive S-100 or actin) showed more frequent tumor necrosis (P=0.048), vimentin expression (P=0.0001), CD117 expression (P=0.001) and activated caspase-3 (P=0.089). IGF-IR could be as important as EGFR for the growth of these neoplasms. Basal cell carcinoma has at least two subtypes with distinct microscopic and immunohistochemical features.
Lerma
Enrique
E
Department of Pathology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain. elerma@santpau.es
Peiro
Gloria
G
Ramón
Teresa
T
Fernandez
Sonia
S
Martinez
Daniel
D
Pons
Cristina
C
Muñoz
Fina
F
Sabate
Josep Ma
JM
Alonso
Carmen
C
Ojeda
Belén
B
Prat
Jaime
J
Barnadas
Agustí
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002280:Basal Cell Carcinoma / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D011980:Receptors, Progesterone / Q000096:biosynthesis*
D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone