224 Response to second-line hormonal therapy following progression on bicalutamide (‘casodex’) 150 MG monotherapy

Das Lokalrezidiv des Prostatakarzinoms: Hormontherapie

BACKGROUND

The majority of patients receive HT after biochemical progression despite primary therapy of prostate cancer with curative intent. It is difficult to differentiate at a low rise in PSA level, e.g., <or=1 ng/ml, between local or systemic recurrence.

MATERIAL AND METHODS

The PSA doubling time (DT) is the most reliable surrogate parameter to decide if HT should be initiated. In practice, however, the trigger PSA is used instead. The latter is closely related to the timing of HT. A high PSA is a contraindication for local salvage therapy. Intermittent HT is apparently as effective as continuous HT and shortens the time of HT exposure.

RESULTS

Traditional HT employs a LHRH agonist, however, the side effect profile is a disadvantage due to the long duration of this treatment, e.g., sarcopenia, osteopenia, or even cognitive impairment. The alternative is nontraditional HT: nonsteroidal antiandrogen (AA) alone such as bicalutamide 150 mg or peripheral androgen blockade (AA plus 5alpha-reductase inhibitor).

CONCLUSION

Even after a long duration of the latter HT the side effects are less pronounced (gynecomastia) and treatable. Particularly in patients with high-risk primary tumors [Gleason score 7(4+3)-10 or an initially high PSA], nontraditional HT may be followed by secondary HT.

Secondary Hormonal Therapy for Advanced Prostate Cancer

PURPOSE

Androgen ablation remains the cornerstone of management for advanced prostate cancer. Therapeutic options in patients with progressive disease following androgen deprivation include antiandrogen withdrawal, secondary hormonal agents and chemotherapy. Multiple secondary hormonal agents have clinical activity and the sequential use of these agents may lead to prolonged periods of clinical response. We provide a state-of-the-art review of the various agents currently used for secondary hormonal manipulation and discusses their role in the systemic treatment of patients with prostate cancer.

MATERIALS AND METHODS

A comprehensive review of the peer reviewed literature was performed on the topic of secondary hormonal therapies, including oral antiandrogens, adrenal androgen inhibitors, corticosteroids, estrogenic compounds, gonadotropin-releasing hormone antagonists and alternative hormonal therapies for advanced prostate cancer.

RESULTS

Secondary hormonal therapies can provide a safe and effective treatment option in patients with AIPC. The use of steroids and adrenolytics, such as ketoconazole and aminoglutethimide, has resulted in symptomatic improvement and a greater than 50% prostate specific antigen decrease in a substantial percent of patients with AIPC. A similar clinical benefit has been demonstrated with estrogen based therapies. Furthermore, these therapies have demonstrated a decrease in metastatic disease burden. Other novel hormonal therapies are currently under investigation and they may also show promise as secondary hormonal therapies. Finally, guidelines from the United States Food and Drug Administration Prostate Cancer Endpoints Workshop were reviewed in the context of developing new agents.

CONCLUSIONS

Secondary hormonal therapy serves as an excellent therapeutic option in patients with AIPC in whom primary hormonal therapy has failed. Practicing urologists should familiarize themselves with these oral medications, their indications and their potential side effects.

Bicalutamide (‘Casodex’) 150 mg in addition to standard care in patients with nonmetastatic prostate cancer: updated results from a randomised double-blind phase III study (median follow-up 5.1 y) in the early prostate cancer programme

Trial 24 is one of three placebo-controlled trials within the ongoing bicalutamide ('Casodex') Early Prostate Cancer (EPC) programme evaluating bicalutamide 150 mg/day in addition to radical prostatectomy, radiotherapy or watchful waiting for T1b-4, any N, M0 prostate cancer. In Trial 24, at 5.1 y median follow-up, the addition of bicalutamide significantly (P < 0.0001) improved objective progression-free survival (PFS) and prostate-specific antigen PFS compared with standard care alone. There was no significant difference in overall survival (P = 0.746). In the context of the whole EPC programme, long-term bicalutamide is not appropriate for localised disease, yet provides advantages in delaying disease progression in patients with locally advanced prostate cancer.

Evaluating the use of early hormonal therapy in patients with localised or locally advanced prostate cancer

This article evaluates the use of early hormonal therapy in patients with localised or locally advanced prostate cancer. In patients receiving radiotherapy, an overall survival benefit is proven for adjuvant goserelin ('Zoladex') in locally advanced disease. Adjuvant to radical prostatectomy, castration (goserelin or orchiectomy) has demonstrated an overall survival benefit in patients with lymph node metastases. Survival advantages have not yet been proven with nonsteroidal antiandrogens, but immediate or adjuvant bicalutamide ('Casodex') improves objective progression-free survival in patients with locally advanced disease, with certain quality-of-life advantages over castration.

Retracted: Additive antitumor effects of the epidermal growth factor receptor tyrosine kinase inhibitor, gefitinib (Iressa), and the nonsteroidal antiandrogen, bicalutamide (Casodex), in prostate cancer cellsin vitro

Progression from an androgen-dependent to an androgen-independent state often occurs in patients with prostate cancer (PCa) who undergo hormonal therapy. We have investigated whether inhibition of the epidermal growth factor receptor (EGFR) signaling pathway affects the antitumor effect of a nonsteroidal antiandrogen. Gefitinib (Iressa), an EGFR tyrosine kinase inhibitor, and bicalutamide (Casodex), a nonsteroidal antiandrogen [androgen receptor (AR) antagonist], were administered alone and in combination to AR-positive human PCa cell lines. FACS analysis showed lower EGFR expression levels on AR-positive cells (LNCaP, CWR22, CWR22R 2152 and AR-transfected DU145 cell lines) compared with AR-negative cells (DU145, PC3 and TSU-Pr1). Moreover, in AR-transfected DU145 cells, chronic treatment with bicalutamide increased EGFR expression to levels similar to androgen-independent DU145 cells. All AR-positive PCa cell lines were sensitive to gefitinib (IC50 = 0.1-0.6 microM), whereas higher concentrations of bicalutamide were needed to reduce AR-positive PCa cell line proliferation (IC50 = 0.8-2.0 microM). Low doses of gefitinib increased the antitumor effects of bicalutamide by strongly reducing the IC50 of bicalutamide (approximately 10-fold). Similarly, bicalutamide increased the antiproliferative effects of gefitinib by reducing the IC50 of gefitinib (approximately 5-fold). Taken together, our data suggest that in androgen-dependent cell lines, addition of gefitinib in combination with bicalutamide results in concurrent dual inhibition of AR and EGFR/HER2 pathways. This causes a significant delay in the onset of EGFR-driven androgen independence.