Bicalutamide as Immediate Therapy Either Alone or as Adjuvant to Standard Care of Patients with Localized or Locally Advanced Prostate Cancer:: First Analysis of the Early Prostate Cancer Program

Efficacy of primary hormone therapy for localized or locally advanced prostate cancer: results of a 10-year follow-up

OBJECTIVE

To evaluate the efficacy of primary hormone therapy for localized or locally advanced prostate cancer, by analysing the 10-year survival rates for men with localized or locally advanced prostate cancer treated with primary hormone therapy or prostatectomy.

PATIENTS AND METHODS

Between February 1993 and March 1995, men with T1b, T1c or T2-3 N0M0 prostate cancer were enrolled. In all, 176 men who had a prostatectomy were assigned to Study 1 and were given adjuvant luteinizing hormone-releasing hormone (LHRH) agonist; 151 men who did not have a prostatectomy were assigned to Study 2 and had LHRH agonist monotherapy or combined androgen blockade. They were followed until death, loss to follow-up, or until the end of the observation period (31 March 2004). We analysed all cases in each study as a single population, and compared Study 1 with Study 2.

RESULTS

The mean patient ages were 67.2 years in Study 1 and 75.7 years in Study 2. During a median of 10.4 years of follow-up, 20 men in Study 1 and 17 in Study 2 died from prostate cancer, and 21 men in Study 1 and 50 in Study 2 died from other causes. In Study 1, the 10-year overall survival rate was 73% and the 10-year cause-specific survival rate was 86%, vs 41% and 78% in Study 2. Overall survival curves were similar to expected survival curves in both studies. There was no significant difference between studies in cause-specific survival.

CONCLUSIONS

The progression of prostate cancer was retarded by primary hormone therapy in men with localized or locally advanced prostate cancer. With primary hormone therapy or prostatectomy, the men had a life-expectancy similar to that of the normal population.

Optimizing outcomes and quality of life in the hormonal treatment of prostate cancer

We review the effectiveness of androgen-deprivation therapy (ADT) in the management of prostate cancer, and the effect that this treatment has on a patient's quality of life (QoL), based on discussions held at a European symposium on the management of prostate cancer. The overall QoL is reduced in asymptomatic men, and there are known decreases in cognitive function, self-esteem, libido and sexual function. Hot flashes are also a frequent problem. Prolonged ADT can lead to osteoporosis and subsequently fractures. Various effective methods exist to manage and minimize these side-effects; some are specific to the side-effect, whereas other more general methods include lifestyle changes, specific drugs and added hormonal manipulations. Intermittent ADT for patients taking luteinizing hormone-releasing hormone agonists offers a promising method to reduce adverse effects, and possibly increases the time to androgen independence. Initial studies indicate that prostate-specific antigen-based progression with intermittent ADT is similar to that seen with continuous ADT, but there is a reduction in side-effects, leading to an improvement in QoL.

Tolerability, efficacy and pharmacokinetics of bicalutamide 300 mg, 450 mg or 600 mg as monotherapy for patients with locally advanced or metastatic prostate cancer, compared with castration

OBJECTIVE

To evaluate the pharmacokinetics, tolerability and effect on endocrinology of bicalutamide given as once-daily monotherapy at doses of >150 mg to patients with locally advanced (M0) or metastatic (M1) prostate cancer, with efficacy as a secondary endpoint.

PATIENTS AND METHODS

Patients were initially enrolled to receive bicalutamide 300 mg in a non-randomized phase, after which further patients were randomized to higher bicalutamide doses (in 150 mg increments) or castration. Overall, 248 patients received bicalutamide at 300 mg (21), 450 mg (95) or 600 mg (42), or castration (90).

RESULTS

Systemic exposure to bicalutamide stabilised at a dose of approximately 300 mg, as determined by pharmacokinetic analysis. The tolerability of high doses of bicalutamide was similar to that of the 150 mg dose, with no increase in the incidence of adverse events. Patients receiving bicalutamide had early increases in the mean levels of oestradiol, testosterone and luteinizing hormone, which were maintained throughout the study. Levels of these hormones rapidly decreased in the castration group and remained low. From baseline (first day of treatment) to 12 weeks there was an equivalent reduction in prostate-specific antigen (PSA) levels across all four groups. At a median follow-up of 5 years, there was no significant survival difference between patients who received bicalutamide and those who received castration, either in M0 or M1 disease.

CONCLUSION

The low median PSA level (180 ng/mL) of patients with M1 disease might account for the lack of survival difference between the treatment groups. Further studies are needed to assess whether high-dose bicalutamide monotherapy can provide equivalent efficacy to castration in patients with M1 prostate cancer.

Bicalutamide 150 mg plus standard care vs standard care alone for early prostate cancer

OBJECTIVE

To evaluate, in the ongoing Early Prostate Cancer (EPC) trial programme, the efficacy and tolerability of bicalutamide 150 mg once daily in addition to standard care for localized or locally advanced, nonmetastatic prostate cancer.

PATIENTS AND METHODS

The EPC programme comprises three randomized, double-blind, placebo-controlled trials designed for combined analysis. Following standard care, 8113 men with localized (T1-2, N0/Nx) or locally advanced (T3-4, any N; or any T, N+) prostate cancer (all M0) received oral bicalutamide 150 mg once daily or oral placebo. The primary endpoints were progression-free survival (PFS) and overall survival.

RESULTS

The large EPC trial programme is defining men who benefit or do not from early or adjuvant antiandrogen therapy. At a median follow-up of 7.4 years, in localized disease there is no benefit to PFS by adding bicalutamide to standard care, and there is a trend (hazard ratio, HR, 1.16; 95% confidence intervals, CI, 0.99-1.37; P = 0.07) towards decreased survival in patients otherwise undergoing watchful waiting. However, in locally advanced disease, bicalutamide significantly improved PFS irrespective of standard care. Bicalutamide significantly improved overall survival in patients receiving radiotherapy (HR 0.65; 95% CI 0.44-0.95; P = 0.03); this was driven by a lower risk of prostate cancer-related deaths. Bicalutamide produced a trend towards improved overall survival in patients with locally advanced disease otherwise undergoing watchful waiting (HR 0.81; 95% CI 0.66-1.01; P = 0.06). No survival difference was evident in the prostatectomy subgroup.

CONCLUSIONS

This ongoing programme is clarifying the role of early or adjuvant antiandrogen therapy in prostate cancer. Patients with localized disease do not appear to derive clinical benefit from added bicalutamide. However, adding bicalutamide 150 mg to standard care provides significant clinical benefits in patients with locally advanced prostate cancer, irrespective of primary therapy.

A proposal for the repositioning of prophylactic breast radiotherapy of prostate cancer patients

Evaluation of: Perdona S, Autorino R, De Placido S et al.: Efficacy of tamoxifen and radiotherapy for prevention and treatment of gynaecomastia and breast pain caused by bicalutamide in prostate cancer: a randomized trial. Lancet Oncol. 6, 295–300 (2005). Patients with prostate cancer treated with small-molecular, nonsteroidal anti-androgens frequently develop mammalgia and gynecomastia. To avoid these unwanted effects, pretherapeutic radiation therapy of the male breasts is in common use. Recent findings on the effectivity of prevention and treatment of breast pain and gynecomastia, by both radiation therapy and tamoxifen, and a new comparative study, necessitate a re-evaluation of current prophylactic and therapeutic treatment options. An evidence-based treatment algorithm is derived that diverges from previous recommendations and redefines the role of preventive and therapeutic radiation therapy. For the propylaxis of gynecomastia and breast pain, tamoxifen is superior to single-dose radiation therapy with 10 Gy. Hence, if tamoxifen for this indication should prove to be safe on longer follow-up, radiation therapy would only be indicated in situations where tamoxifen therapy is impossible or contraindicated. The same is proposed for the treatment of early gynecomastia or breast pain except with tamoxifen treatment failure as an additional indication. Higher radiation doses of 4 x 5 Gy, which were shown to be effective in this setting, have not yet been evaluated against anti-estrogen therapy.

Hepatotoxicity induced by antiandrogens: a review of the literature

INTRODUCTION

Hepatotoxicity is a serious adverse reaction potentially induced by all antiandrogens. We have reviewed here the published cases of hepatotoxicity induced by steroidal and nonsteroidal antiandrogens, and compared the type and characteristics of liver damage.

METHODS

Using two different databases: MEDLINE and IDIS (Iowa Drug Information Service), we searched for published cases of liver injury induced by antiandrogens. Analysis was made of the type of hepatotoxicity, therapeutic indication, other pharmacological treatments and evolution. Mean values of latency and recovery periods of the adverse reactions and liver function tests were also evaluated.

RESULTS

Hepatitis was the most common type of hepatotoxicity reported, and was associated with all antiandrogens. This adverse reaction does not seem to be dependent on the patients age, therapeutic indication or the dose prescribed. Hepatitis showed a longer latency period for cyproterone acetate than for flutamide. Some transaminase levels were significantly higher for flutamide than for cyproterone acetate, although the evolution was no worse in the cases reported for flutamide. We also found occasional reports of hepatocellular carcinoma and hepatic cirrhosis suspected of being induced by cyproterone acetate.

CONCLUSION

Although there are differences in the clinical features of hepatotoxicity induced by steroidal and nonsteroidal antiandrogens, these do not predict which patients will develop hepatotoxicity during treatment or evolution. Serial liver function tests are required for early detection of liver damage.

Endocrine therapy with or without radical prostatectomy for T1b-T3N0M0 prostate cancer

BACKGROUND

We retrospectively compared the 5-year survival rates of T1b-T3N0M0 prostate cancer patients treated either by endocrine therapy plus radical prostatectomy or endocrine therapy alone.

METHODS

Clinical T1b-T3N0M0 prostate cancer patients were enrolled at 104 institutions in Japan. They were assigned to study 1 (n = 176), if they were indicated to prostatectomy, if not indicated, they were assigned to study 2 (n = 151). The indication of prostatectomy was based on the clinical judgement of physicians and/or patients. Those assigned to study 1 underwent prostatectomy and adjuvant endocrine therapy with or without preoperative androgen deprivation. Those assigned to study 2 were treated with leuprorelin acetate with or without chlormadinone acetate. They were followed-up every 3 months until death or for 5 years and over.

RESULTS

Those assigned to study 1 were younger (mean age 67.2 vs 75.7 years), less advanced in clinical stage, and had lower prostate specific antigen levels (mean 43.8 vs 103.6 ng/mL). Death for any reason was observed less frequently in study 1 (n = 29, 16%) than study 2 (n = 50, 33%), and the 5-year overall survival rate was higher in study 1 (87 vs. 68%). However, prostate cancer deaths were comparatively seldom (9% in study 1 and 7% in study 2), resulting in the identical 5-year cause specific survival rate in both study groups (91%). In both study groups the overall survival was almost equal to the natural survival of age-matched men.

CONCLUSIONS

Endocrine therapy offers a reasonable survival rate in T1b-T3 prostate cancer patients within a 5-year follow-up. Observation will be extended to determine 10-year outcomes.

Adjuvant goserelin improves clinical disease-free survival and reduces disease-related mortality in patients with locally advanced or localized prostate cancer

This article reviews the clinical disease-free survival (DFS) and disease-related mortality (DRM) data from published prospective, randomized trials of goserelin, given alone as adjuvant treatment or combined with a nonsteroidal antiandrogen as neoadjuvant treatment in patients with locally advanced or localized prostate cancer. Four trials were of radiotherapy and one of radical prostatectomy. The five trials included > 3500 patients and the median follow-up was 4.8-7.1 years. There were statistically significant improvements in clinical DFS with goserelin support relative to the control treatment in all five trials (each log-rank P </= 0.004). Reductions in the risk of DRM were statistically significant with adjuvant goserelin vs no adjuvant treatment to support radiotherapy in one trial, and with adjuvant goserelin or bilateral orchidectomy vs no adjuvant treatment to support radical prostatectomy in another (each log-rank P </= 0.001). Time-point estimates of the rates of clinical DFS and DRM were in favour of goserelin support vs control in all five trials at 5 years and in the three trials for which data were available at 8 years. Goserelin support therefore improves clinical DFS and reduces DRM after radiotherapy or radical prostatectomy. Adjuvant goserelin may offer greater clinical benefits than neoadjuvant hormonal treatment.

Adjuvant hormonal treatment for prostate cancer: the bicalutamide early prostate cancer program

Adjuvant hormonal therapy has been demonstrated to be able to delay disease progression in nonmetastatic prostate cancer. To date, however, a favorable impact on survival has only been demonstrated in lymph-node-positive disease and in external-beam radiotherapy series with locally advanced and probably mainly micrometastatic tumors. The Bicalutamide Early Prostate Cancer Program is the largest study under way to define the role of adjuvant treatment in early prostate cancer and identify subgroups of patients likely to benefit from immediate hormonal therapy. At the time of the most recently published analysis, the risk of objective clinical progression was significantly reduced in the bicalutamide arm (hazards ratio 0.58, 95% confidence interval 0.51-0.66, p < 0.0001). However, further maturation of data is needed to see whether this difference will lead to a survival advantage.