Open AccessFrequent KIT and epidermal growth factor receptor overexpressions in undifferentiated‐type breast carcinomas with ‘stem‐cell‐like’ features
Author(s) -
Tsuda Hitoshi,
Tani Yoichi,
Weisenberger Joel,
Kitada Shigehiro,
Hasegawa Tadashi,
Murata Tetsuya,
Tamai Seiichi,
Hirohashi Setsuo,
Matsubara Osamu,
Natori Tsuneo
Publication year - 2005
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/j.1349-7006.2005.00060.x
Subject(s) - myoepithelial cell , metaplastic carcinoma , epidermal growth factor receptor , pathology , carcinoma , biology , epidermal growth factor , immunohistochemistry , vimentin , stem cell , breast carcinoma , cancer research , receptor , medicine , breast cancer , cancer , biochemistry , genetics
It was hypothesized that four histopathological types or subtypes of breast carcinoma were undifferentiated types characterized by bidirectional differentiation toward both luminal epithelial and myoepithelial cells and had characteristic molecular changes: invasive ductal carcinoma (IDC) with a large central acellular zone, atypical medullary carcinoma (a subgroup in Grade 3 solid‐tubular carcinoma), matrix‐producing carcinoma, and spindle‐cell carcinoma (or carcinoma with spindle‐cell metaplasia). In 32 cases of the undifferentiated type and 37 cases of the relatively differentiated types, we immunohistochemically examined the expressions of myoepithelial markers and KIT, epidermal growth factor receptor (EGFR), and c‐erbB‐2 oncoproteins. Vimentin, S‐100, and α‐smooth muscle actin were positive in 28 (88%), 22 (69%), and 15 (47%) of the undifferentiated types, but were positive in seven (19%), one (3%), and one (3%) of relatively differentiated types ( P < 0.0001). KIT and EGFR overexpressions were detected more frequently in the undifferentiated types (34 and 88%, respectively) than in relatively differentiated types (3 and 3%, respectively) ( P < 0.0001, for both). In 11 (85%) of 13 cases with KIT overexpression, EGFR overexpression concurred. c‐erbB‐2 overexpression was almost equally detected in both the undifferentiated and relatively differentiated types, and did not correlate with KIT or EGFR overexpression. Phosphotyrosine was detected in 16 (67%) of 24 cases with KIT, EGFR, and/or c‐erbB‐2 overexpression but only in six (18%) of 34 cases without KIT, EGFR, or c‐erbB‐2 overexpression ( P = 0.0002). The undifferentiated‐type breast carcinomas appeared to show mammary epithelial stem cell‐like features, and they could be identified by KIT and/or EGFR overexpressions. ( Cancer Sci 2005; 96: 333–339)