[Relationship between epithelial-mesenchymal transition and basal cell-like phenotype in breast cancer]

To evaluate the relationship between epithelial-mesenchymal transition and basal cell-like phenotype breast cancer (BLBC).

Three hundred and eighty two cases of breast cancers including basal cell-like, luminal A, luminal B and Her-2 subtypes were collected from 458 cases of invasive breast cancers based on their immunophenotypes. They were then stained immunohistochemically with FOXC-2, vimentin, Syndecan-1 and E-cadherin. The relationship of these markers with the basal cell-like phenotype of breast cancer was studied.

Of the 41 BLBC cases, FOXC-2, vimentin and Syndecan-1 were positive in 14 cases (34.1%), 18 cases (43.9%) and 36 cases (87.7%) respectively; E-cadherin expression was reduced in 26 cases (63.4%). The positive rates of FOXC-2 and vimentin were higher in BLBC than in other subtypes of breast cancer (P < 0.01). The expression of E-cadherin was the lowest among the 4 subtypes of breast cancers (P < 0.01). Syndecan-1 was positive in the stromal cells adjacent to cancer cells in 17 cases (41.5%) BLBC and the expression was higher than that in other subtypes (P = 0.007). There existed a correlation between FOXC-2 and vimentin expression in BLBC (r = 0.607, P < 0.01). The rates of positive lymph nodes in FOXC-2 and vimentin positive BLBC cases were 71.4% and 66.7% respectively, and both were higher than those of FOXC-2 and vimentin negative BLBC cases (P = 0.002 and P = 0.001).

Epithelial-mesenchymal transition is probably related to the basal cell-like phenotype of breast cancers, and this may be one of the reasons accounting for the different biological behavior of BLBC from other subtypes of breast cancer.