RT Journal Article
SR Electronic
T1 MED12 protein expression in breast fibroepithelial lesions: correlation with mutation status and oestrogen receptor expression
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 858
OP 865
DO 10.1136/jclinpath-2015-203590
VO 69
IS 10
A1 Tan, Wai Jin
A1 Chan, Jason Yongsheng
A1 Thike, Aye Aye
A1 Lim, Jeffrey Chun Tatt
A1 Md Nasir, Nur Diyana
A1 Tan, Jane Sie Yong
A1 Koh, Valerie Cui Yun
A1 Lim, Weng Khong
A1 Tan, Jing
A1 Ng, Cedric Chuan Yong
A1 Rajasegaran, Vikneswari
A1 Nagarajan, Sanjanaa
A1 Bay, Boon Huat
A1 Teh, Bin Tean
A1 Tan, Puay Hoon
YR 2016
UL http://jcp.bmj.com/content/69/10/858.abstract
AB Aims Recent reports have identified recurrent MED12 somatic mutations in fibroadenomas and phyllodes tumours. The frequency and type of somatic mutations were noted to be similar to those of uterine leiomyomas. We aimed to investigate protein expression of MED12, correlating it to MED12 mutational status and expression of oestrogen receptors (ER).Methods Immunohistochemistry was performed on a total of 232 fibroepithelial lesions (100 fibroadenomas, 132 phyllodes tumours) diagnosed at the Department of Pathology, Singapore General Hospital using MED12, ERα and ERβ antibodies. Expressions were evaluated in both stroma and epithelium, and correlated with MED12 mutational status.Results MED12 mutation was significantly associated with high MED12 protein expression (H-score >150) in the stroma (p=0.029), but not in the epithelium. It was not associated with ERα and ERβ protein expression in both stroma and epithelium. MED12 protein expression was significantly correlated with ERα in epithelial (p=0.007) and ERβ in stromal (p=0.049) components. MED12 was not significantly different between fibroadenomas and phyllodes tumours. Epithelial expression of ERα was significantly higher in fibroadenomas (p<0.001) than in phyllodes tumours. Conversely, both epithelial and stromal expression of ERβ was significantly higher in phyllodes tumours (p<0.001).Conclusions Positive associations observed between MED12 and ERα, ERβ immunohistochemical expression suggest a biological interplay between the proteins. The lack of significant association of MED12 mutation with ER protein expression indicates a need to further explore the functional impact of MED12 mutations on the ER signalling pathway in breast fibroepithelial lesions.