The purpose of this study is to determine if treatment with fulvestrant leads to a slowing of tumor progression in patients who have developed androgen-independent (AIPC) or hormone-refractory prostate cancer (HRPC) and who have a rising serum prostate specific antigen (PSA). In vitro studies have shown that fulvestrant downregulates androgen receptor (AR) in LNCaP cancer cell lines to a significant extent, thereby inhibiting growth of tumor cells. In addition, it is important to emphasize that fulvestrant has also been found to decrease growth of AR-negative prostate cancer cells. These observations provide the rational for using fulvestrant for the treatment of AIPC and HRPC.
