Steroid Hormone Receptor Expression in Renal Cell Carcinoma: An Immunohistochemical Analysis of 182 Tumors

Abstract
Purpose: Steroid hormone receptor expression has an essential role in cancer of the prostate and breast but there is only limited experience with renal cell carcinoma (RCC), especially regarding prognostic and therapeutic impact. Materials and Methods: A total of 188 cases of RCC were stained immunohistochemically for the expression of estrogen (ER), progesterone (PR) and androgen (AR) receptors using a tissue microarray technique. Nuclear steroid hormone receptor immunoreactivities were analyzed semiquantitatively with respect to associations with histological subtype, pT stage, grading and gender using Fisher's exact test. Impact on disease-free survival was analyzed using the Kaplan-Meier method. Results: Sufficient tumor tissue was present in 182 of the 188 RCCs. AR expression was found in 27 of 182 tumors (14.8%) in 24 male and 3 female patients. AR expression was significantly associated with stage pT1 compared with pT3 (p <0.0001), and grades 1 and 2 compared with grade 3 (p = 0.0005). Regarding progression-free survival, AR positive RCCs showed a significantly better prognosis than AR negative cases (log rank test, p = 0.027). No difference of AR immunoreactivity could be detected between histological subtypes. Only 2 of the 182 cases (1.1%) showed ER and PR immunoreactivity in less than 10% of tumor cell nuclei. Conclusions: While ER and PR expression was the exception, AR expression was found in almost 15% of the tumors and it was significantly associated with low stage, well or moderately differentiated tumors and a favorable outcome, decreasing with tumor growth and dedifferentiation. However, these results do not support a potential role of hormonal therapy for metastatic RCC.