Hormone receptors expression in phyllodes tumors of the breast.

Objective: To ascertain the hormonal receptor profiles of the epithelial and stromal components of phyllodes tumors (PTs) and determine their relationship with stromal proliferation.

Study design: Eighty-two PTs (50 benign, 22 borderline, and 10 malignant) were studied. Automated immunohistochemical staining for estrogen receptor (ER)-alpha and -beta, progesterone receptor (PR), androgen receptor (AR), and Ki-67 was performed using tissue microarray blocks, and their expression was assessed in both the stromal and epithelial components.

Results: The epithelial component demonstrated the expression for ER-alpha (45.6%, 36 of 79), ER-beta (37.2%, 29 of 78), PR (91.1%, 72 of 79), and AR (10.1%, 8 of 79). The stromal component was positive for ER-beta (29.3%, 24 of 82) only. The epithelial expression of ER-beta was found to be significantly correlated with the epithelial expression of AR (r = 0.352, p = 0.002). No association was found between hormone receptor expression and PT tumor grade. Stromal Ki-67 expression was statistically correlated with epithelial ER-beta, epithelial AR, and stromal ER-beta expression.

Conclusion: Epithelial and stromal ER-beta and epithelial AR expression in PTs was correlated with the proliferative rate in the stromal component. Immunohistochemical examination of ER-beta and AR may have some impact on the postoperative management of patients with PTs.