Ki-67 and AR expression and its relationship with recurrence in triple-negative breast cancer

Abstract

Objective To investigate the expressions of cellular proliferative antigen (Ki-67) and androgen receptor (AR) in triple-negative breast cancer (TNBC) and their relationships with recurrence. Methods Sixty-six cases of TNBC and two hundred and fifteen cases of non triple-negative breast cancer (NTNBC) tissues between January 2006 and December 2010 in Jiangmen Hospital Affiliated to Sun Yat-sen University were collected, the expressions of Ki-67 and AR were detected by immunohistochemical, and through follow-up the relationships between TNBC recurrence and the expressions of Ki-67 and AR were analyzed. SPSS 19.0 was used to analyze the results. Results The positive rate of Ki-67 in TNBC (75.76%, 50/66) was significantly higher than that in NTNBC (62.33%, 134/215, χ2=4.031, P=0.045), and Ki-67 expression was correlated with histological grade (χ2=6.031, P=0.049), tumor diameter (χ2=6.630, P=0.036) and lymph node metastasis (χ2=5.440, P=0.020). The positive rate of AR in TNBC (31.82%, 21/66) was significantly lower than that in NTNBC (76.28%, 164/215, χ2=44.382, P<0.001), and AR expression was correlated with menopausal status (χ2=5.341, P=0.021) and body mass index (χ2=4.369, P=0.037). TNBC recurrence was related to Ki-67 expression (χ2=4.125, P=0.042), and was not related to AR expression (χ2=1.257, P=0.262). Conclusion High expression level of Ki-67 and low expression level of AR are characteristics of TNBC. Ki-67 positive patients are more likely to relapse, and it can be used as an indicator to predict TNBC recurrence. Key words: Breast neoplasms; Immunohistochemistry; Recurrence