Cinical Significance of Androgen Receptor, CK-5/6, KI-67 and Molecular Subtypes in Breast Cancer.
OBJECTIVE
To detect the relationship between molecular subtypes of breast cancer with expressions of androgen receptor, cytokeratin 5/6 (CK5/6)and Ki-67.


METHODS
Expressions of androgen receptor, CK-5/6 and Ki-67 were determined by immunohistochemistry in paraffin-embedded sections obtained from 86 invasive breast cancer cases of stages I/IIa/IIb in 4 molecular subtypes. Patients treated for recurrent disease and locally advanced disease were excluded.


RESULTS
Forty one luminal A cases, ie. positive estrogen receptor(ER) and/or progesteron receptor (PR) with negative epidermal growth factor receptor (HER2), 14 luminal B, ie. positive ER and/or PR and positive HER2, 14 HER2-enriched (HER2+), ie. negative ER and PR with positive HER2, and 17 triple negative (negative ER and PR and HER2) invasive breast cancers were included. Mean follow-up was 17.46±11.70 mo. Androgen receptor-negativity and CK5/6-positivity were significantly more common in HER2+ and triple negative groups. Ki-67 and histological grade were higher in HER2+ group, significantly. Two deaths were triple negative (P=0.04). Androgen receptor-negativity, CK5/6 and Ki-67 status did not affect survival or systemic metastases, significantly. All groups had local recurrences. Local recurrence was significantly associated with androgen receptor-negativity in luminal A and high Ki-67 value in HER2+ groups. Systemic metastases were significantly more common in triple negative and HER2+ groups.


CONCLUSIONS
Molecular subtypes of breast cancer are prognostic and predictive. Androgen receptor is expressed more commonly in luminal subtypes with better prognosis and androgen receptor negativity is associated with development of local recurrence in luminal A cancers.
Department of General Surgery, Bezmialem Vakif University Faculty of Medicine, İstanbul, Turkey.
Münire
M
Kayahan
Department of General Surgery, Bezmialem Vakif University Faculty of Medicine, İstanbul, Turkey.
Ufuk Oğuz
UO
İdiz
Department of Pathology, Bezmialem Vakif University Faculty of Medicine, İstanbul, Turkey.
Zuhal
Z
Gucin
Department of General Surgery, Haseki Training and Research Hospital, İstanbul, Turkey.
Fazilet
F
Erözgen
Department of General Surgery, Bezmialem Vakif University Faculty of Medicine, İstanbul, Turkey.
Naim
N
Memmi
Department of General Surgery, Bezmialem Vakif University Faculty of Medicine, İstanbul, Turkey.
Mahmut
M
Müslümanoğlu
Androgen receptor; breast cancer; cytokeratin; ki-67 antigen; molecular typing