more attention to subtypes of male breast cancer

Lani · 05-16-2009, 10:29 PM

Breast Cancer Research
Volume 11
Issue 3

Research article
Immunohistochemical characterization of subtypes of male breast carcinoma
Yimin Ge , Nour Sneige , Mahmoud A Eltorky , Zhiqin Wang , E Lin , Yun Gong and Ming Guo

Breast Cancer Research 2009, 11:R28doi:10.1186/bcr2258

Published: 14 May 2009
Abstract (provisional)

Introduction
Male breast cancer accounts for around 1% of all breast cancer cases but has a rising incidence in recent years. This study is aimed to classify the molecular subtypes of male breast cancers based on the expression profile of immunomarkers and to evaluate their association with clinicopathological features and expression patterns of epidermal growth factor receptor (EGFR) and nuclear factor kappa-B (NF-kB).

Methods
A total of 42 cases of male breast carcinoma were examined retrospectively using immunostains for estrogen receptor (ER), progesterone receptor (PR), cytokeratin 5/6 (CK5/6), EGFR, and NF-kB. HER2 expression was evaluated by immunostaining and confirmed by fluorescent in situ hybridization (FISH).

Results
The luminal A subtype was the most common subtype in male breast cancer (83%, 35/42), which was followed by the luminal B subtype (17%, 7/42). Basal-like and HER2+/ER- subtypes were not identified in this group. All carcinomas expressed ER and 67% of them were PR positive. High nuclear grades were more common in luminal B subtype (71%, 5/7) than that in luminal A subtype (34%, 12/35). The luminal B subtype carcinomas expressed EGFR (42%, 3/7) and NF-kB (57%, 4/7) more frequently than the luminal A subtype did (17%, 6/35 and 37%, 13/35, respectively).

Conclusions
In our study group, luminal A and B subtypes were the major subtypes of male breast carcinoma. The immunophenotypical features of male breast cancer differ from those of its female counterpart. Luminal B subtype tended to have high nuclear grade and more frequent expression of EGFR and NF-kB.

The entire article is available for open viewing at breast cancer research|.org