Double-blind, randomized study of primary hormonal treatment of stage D2 prostate carcinoma: flutamide versus diethylstilbestrol

Finasteride and flutamide therapy in patients with advanced prostate cancer: response to subsequent castration and long-term follow-up

OBJECTIVES

To report the efficacy of castration after progression on finasteride and flutamide. Standard androgen deprivation strategies for prostate cancer typically lead to castrate levels of testosterone. One alternative is the use of finasteride and flutamide.

METHODS

A Phase II trial evaluated the combination of finasteride (5 mg/day) and flutamide (250 mg three times daily) in patients with rising prostate-specific antigen levels after local treatment for prostate cancer or with newly discovered metastatic disease. Patients were followed up for subsequent events, including castration-free, androgen-independent prostate cancer (AIPC)-free, and overall survival.

RESULTS

With a median follow-up of 88 months, 5 patients (25%) continued on finasteride and flutamide, and 12 had stopped this combination and subsequently underwent medical or surgical castration. No patients experienced a flutamide withdrawal effect. All patients experienced more than a 50% decline in prostate-specific antigen after castration (mean 89%). The median protocol treatment failure-free survival was 29.9 months, the median castration-free survival was 37 months, and the median AIPC-free survival was 48.6 months. At 5 years, the overall survival rate was 65% (95% confidence interval 47% to 90%); 29% were alive and have not required castration, and 35% were alive and free of AIPC.

CONCLUSIONS

Finasteride and flutamide have a durable effect in suppressing prostate-specific antigen progression in some men with advanced prostate cancer. Furthermore, castration induces secondary responses that may be of shorter duration than if started initially, although the overall period of hormonally responsive prostate cancer is more than 4 years.

Neoadjuvant flutamide monotherapy for locally confined prostate cancer

BACKGROUND

We compared the clinical effects and impact on quality of life (QOL) of patients who received a 3-month course of flutamide monotherapy before radical prostatectomy with those who received a 3-month course of luteinizing hormone-releasing hormone (LHRH) agonist monotherapy.

METHODS

Thirty-seven patients with non-metastatic prostate cancer were enrolled in this study (19, flutamide; 18, LHRH agonist). The rates of change of serum prostate-specific antigen (PSA) and testosterone levels, downsizing of prostate volume, the rate of organ confined disease, adverse effects and perioperative scores measured using the European Organization for Research and Treatment of Cancer Prostate Cancer Quality of Life Questionnaire (EORTC-P) and the Sapporo Medical University Sexual Function Questionnaire (SMUF) were analyzed.

RESULTS

At radical prostatectomy, pathological variables were not significantly different in the two groups. Serum testosterone level was significantly higher (mean 359.2 compared to 10.5, P < 0.001), complete response rate of PSA (13% compared to 57%, P = 0.028) and rate of downsizing of prostate volume (mean, -17.7% compared to -35.4%, P = 0.038) were significantly lower in the flutamide group than in the LHRH group. After neoadjuvant hormone therapy, the scores on the sexual problem domain of EORTC-P (P = 0.033) and sexual desire score of SMUF (P = 0.021) were significantly higher in the flutamide group than in the LHRH group. At a median follow-up of 34 months after prostatectomy, biochemical failure-free survival rate in the flutamide group did not differ from that in the LHRH group.

CONCLUSION

This study suggests that flutamide monotherapy can be an acceptable modality as an option for neoadjuvant hormone therapy.

The role of antiandrogen monotherapy in the treatment of prostate cancer

The mainstay of hormonal therapy in prostate cancer has been medical or surgical castration, both of which are associated with loss of libido and impotence, and may not always be acceptable to the patient. Antiandrogen monotherapy is an alternative treatment option to castration. There are two types of antiandrogen, i.e. steroidal (cyproterone acetate, CPA), and nonsteroidal (bicalutamide, flutamide and nilutamide). Data comparing survival outcome with CPA and castration are limited and conflicting. Furthermore, CPA is associated with loss of libido and erectile dysfunction. Large phase III trials have established that monotherapy with bicalutamide 150 mg once daily provides a survival outcome that is not significantly different to that after castration in men with locally advanced, non-metastatic disease, while conferring significant advantages for sexual interest and physical capacity. Current data are inadequate to draw conclusions on the comparative efficacy of flutamide and castration, while nilutamide is not licensed for monotherapy. Recent data reveal that bicalutamide 150 mg given once daily in addition to standard care (radical prostatectomy, radiotherapy or 'watchful waiting') significantly delays the progression of early (localized or locally advanced) prostate cancer. Bicalutamide has a more favourable side-effect profile than the other antiandrogens and is more likely to promote compliance.

Does prophylactic breast irradiation prevent antiandrogen-induced gynecomastia? Evaluation of 253 patients in the randomized Scandinavian trial SPCG-7/SFUO-3

OBJECTIVES

To examine the development of antiandrogen-induced gynecomastia and breast tenderness in the first 253 patients in a randomized Scandinavian trial (SPCG-7/SFUO-3) with a 12-month complete follow-up evaluation performed by both doctors and patients.

METHODS

In this study, the treating doctor and patient decided whether prophylactic irradiation (RT) of the breast should be given to prevent antiandrogen-induced gynecomastia. At each visit, the doctor evaluated the occurrence of gynecomastia and breast tenderness. Questions about gynecomastia and breast tenderness were also included in the study quality-of-life questionnaire (Prostate Cancer Symptom Scale).

RESULTS

Mammary RT with mostly single fraction (12 to 15 Gy) electrons was given to 174 (69%) of the 253 evaluated patients. At the 1-year follow-up visit, the doctor evaluations indicated some form of gynecomastia in 71% and 28% (P <0.001) of the nonirradiated (no-RT) and irradiated (RT) patients, respectively. The patient evaluations at 1 year showed some form of breast enlargement in 78% and 44% (P <0.001) of the no-RT and RT patients, respectively. The doctors reported some form of breast tenderness at 1 year in 75% and 43% (P <0.001) of the no-RT and RT patients, respectively. The patient evaluations of breast tenderness show an expected significant increase in the RT arm at the 3-month follow-up, which was probably due to skin reactions. At 1 year, significantly more patients who marked "very much" on the Prostate Cancer Symptom Scale were seen in the no-RT group. A weak correlation between the doctors' and patients' detection of breast problems was observed.

CONCLUSIONS

The results show that, with high significance, prophylactic RT of the breast decreases the risk of antiandrogen-induced gynecomastia and breast tenderness.

The safety and tolerability of low-dose irradiation for the management of gynaecomastia caused by antiandrogen monotherapy

Gynaecomastia--a benign and often painful enlargement of the male breast--is a common side-effect of some therapies for prostate cancer, including non-steroidal antiandrogen monotherapy. Although gynaecomastia and breast pain are not harmful to the overall health of the patient, they can be serious enough to influence treatment decisions in the management of prostate cancer. Prophylactic low-dose irradiation can be effective in reducing the incidence and severity of both gynaecomastia and breast pain. In addition, irradiation may be effective in treating breast pain due to the development of gynaecomastia. Low-dose electron irradiation confers advantageous tissue dosing, is well tolerated, and has manageable side-effects, the most common of which is reversible skin erythema. Information on long-term safety after irradiation for gynaecomastia is limited at present, but trials are underway. Irradiation is likely to be an effective management option with an acceptable low risk of long-term complications for gynaecomastia associated with hormone therapy for prostate cancer.

Is there a role for antiandrogen monotherapy in patients with metastatic prostate cancer?

Castration is the most widely used form of androgen ablation employed in the treatment of metastatic (M1) prostate cancer. Non-steroidal antiandrogen monotherapy is a potential alternative treatment option for men for whom castration is unacceptable or not indicated. Of the three non-steroidal antiandrogens, bicalutamide ('Casodex'), flutamide and nilutamide, only bicalutamide has been compared with castration in large, controlled, randomised, Phase III trials in M1 patients. A post-hoc analysis of these studies indicated that bicalutamide 150 mg/day monotherapy may be of benefit to M1 patients with a prostate specific antigen (PSA) level </=400 ng/ml. Significant advantages for M1 patients treated with bicalutamide were observed in subjective response rate, maintenance of sexual interest and physical capacity. Patients with a higher disease burden (PSA >400 ng/ml) may decide that quality of life and symptomatic benefits outweigh the slight survival disadvantage seen in clinical trials and opt for bicalutamide monotherapy as an alternative to castration.Prostate Cancer and Prostatic Diseases (2001) 4, 196-203.

Bicalutamide monotherapy versus flutamide plus goserelin in prostate cancer: updated results of a multicentric trial

OBJECTIVES

To compare the efficacy of bicalutamide monotherapy to maximal androgen blockade in advanced prostatic cancer.

PATIENTS AND METHODS

Previously untreated patients with histologically proven stage C or D (American Urological Association Staging System) disease were randomly allocated to either bicalutamide (B) or goserelin plus flutamide (G+F). After disease progression, patients treated with B were assigned to castration. The primary endpoint for this trial was overall survival. Prostate cancer-specific survival and progression were included among secondary endpoints.

RESULTS

In total 108 patients received B and 112 received G+F. At a median follow-up time of 54 months (range 1-89), 151 patients progressed and 113 died. There was no significant difference in the duration of either progression-free or overall survival. Hazards of progression, death and cancer-specific death, corrected by disease stage, tumor grade and baseline PSA level, showed that patients initially assigned to B had a higher risk of progression but a comparable risk of death and cancer-specific death with the exception of patients with G3 tumors who had an increased risk of death).

CONCLUSIONS

In patients with well or moderately well differentiated tumors, B monotherapy followed by castration may offer the same survival chance as maximal androgen deprivation. In those patients it thus represents a reasonable choice that can avoid the side effects of androgen deprivation for considerable periods of time.

Antiandrogen monotherapy: indications and results

Many patients with prostate cancer for whom hormonal therapy is indicated are still physically and sexually active; quality of life is therefore a vital issue when considering treatment options. Traditional castration-based therapies, although effective, have implications with respect to quality of life, causing loss of libido, impotence, fatigue, and reduced bone mineral density. Monotherapy with a nonsteroidal antiandrogen is an attractive therapeutic alternative to castration, offering effective therapy with potential quality-of-life benefits. Of the available nonsteroidal antiandrogens, bicalutamide has been most extensively evaluated in the monotherapy setting. Mature combined data (56% mortality) from 2 large randomized studies show no statistically significant difference in overall survival between bicalutamide 150-mg monotherapy and castration in patients with locally advanced, nonmetastatic (stage M0) disease. Survival outcome in patients with metastatic (stage M1) disease (43% mortality) favored castration, although the difference in median survival between the groups was only 6 weeks. Bicalutamide 150-mg monotherapy was associated with significant advantages compared with castration, in terms of sexual interest and physical capacity, in patients with either M0 and M1 stage disease. Data from a small subgroup of patients with stage M0 disease suggest that bicalutamide may also reduce the risk of osteoporosis compared with castration. Long-term therapy with bicalutamide 150-mg monotherapy is generally well tolerated, with a predictable side-effect profile. The most common side effects are male breast pain and gynecomastia. Emerging evidence also supports the use of bicalutamide 150 mg, both as immediate monotherapy and as adjuvant therapy in early stage (localized or locally advanced) prostate cancer.

Prospective randomised trial comparing diethylstilboestrol and flutamide in the treatment of hormone relapsed prostate cancer

BACKGROUND

Patients with hormone relapsed prostate cancer (HRPC) are often treated with flutamide or diethylstilboestrol. However, which of these two options is the best treatment for HRPC remains unclear.

METHODS

We carried out a prospective study to determine and compare the prostate-specific antigen (PSA) response and survival in patients with hormone relapsed prostate cancer (HRPC), all of whom had previously shown a good response to medical or surgical castration. The patients were randomised to treatment with diethylstilboestrol (DES) and aspirin, or the antiandrogen flutamide. In addition, quality of life was determined by interview and questionnaire.

RESULTS

Twenty-eight patients were randomised for treatment options. There was a significantly greater fall in the PSA (65% vs 35%; P = 0.034) after treatment with diethylstilboestrol compared to treatment with flutamide. Median survival also rose after treatment with diethylstilboestrol (18 months) compared to flutamide (11 months), but this difference did not reach statistical significance. There was no difference in the quality of life parameters between the two groups. There were no cardiovascular complications in the stilboestrol group.

CONCLUSIONS

In HRPC, treatment with stilboestrol is associated with a greater PSA fall and an increase in median survival when compared to flutamide treatment.

Clinical predictors of androgen-independent prostate cancer and survival in the prostate-specific antigen era

OBJECTIVES

To further characterize and identify novel predictors of androgen-independent prostate cancer (AIPC) and survival in the prostate-specific antigen (PSA) era.

METHODS

A total of 184 consecutive patients with prostate cancer receiving chronic androgen suppression were assessed for the development of AIPC and overall survival.

RESULTS

The median time to development of AIPC was 44 months (Stage M+ = 24 months; Stage M0 = 63 months, P = 0.000001). The 10-year overall survival rate for Stage M0 or M+ disease was 89% and 55%, respectively. AIPC developed significantly more commonly in patients with a higher nadir PSA level (greater than 1 ng/dL), a longer time to reach nadir PSA (greater than 3 months), a larger body mass index (greater than 27 kg/m2), greater pretherapy PSA level, and when evidence of metastatic disease was identified (logistic regression analysis). Overall survival was significantly associated with advanced stage (skeletal metastases), pretreatment PSA level, and history of skeletal fracture (multivariate Cox regression analysis).

CONCLUSIONS

In the PSA era, longer intervals of androgen suppression therapy in nonmetastatic, biochemically recurrent prostate cancer have translated into a change in the duration of androgen-dependent prostate cancer. Although the duration of androgen dependence remains variable, prolonged--possibly "curative"--control exists in a subset of patients. Obese men developed AIPC significantly sooner than did slender men. A skeletal fracture was a significant negative predictor of overall survival. These observations form the basis for nomogram predictions of AIPC in the PSA era.

Selected contribution: Effects of sex and ovariectomy on responses to platelets in porcine femoral veins

Estrogen replacement increases risk of venous thrombosis. In this study, we determined responses in vitro to platelets and platelet products in veins from adult male and intact and ovariectomized female pigs. When contracted with prostaglandin F(2alpha), platelets (25,000 platelets/microl) caused relaxation in veins with endothelium. Higher numbers of platelets caused contraction in veins with and without endothelium. In veins without endothelium, contractions were greater in veins from male than in veins from female pigs, and contractions in intact female pig veins were greater than in ovariectomized females pig veins. Platelet products 5-hydroxytryptamine and thromboxane (analog U-46619) caused comparable contractions in all veins; contractions to prostacyclin were less in veins from intact female pigs. ADP caused comparable endothelium-dependent relaxations in all groups. These relaxations were increased by indomethacin in veins from intact males and females; with inhibition of nitric oxide, relaxations were comparable in all groups. These results suggest that venous responses to platelets vary with sex and presence of ovaries in female pigs. These variations reflect differences in type and quantity of substances released from platelets as well as the sensitivity of the smooth muscle to some vasoactive substances. In addition, products of cyclooxygenase may reduce endothelium-dependent relaxations in veins.

Antiandrogen monotherapy: a new form of treatment for patients with prostate cancer

Nonsteroidal antiandrogens are generally used in conjunction with castration as combined androgen blockade. However, the changing profile of patients with prostate cancer has made monotherapy with a nonsteroidal antiandrogen an attractive alternative therapeutic approach, offering potential quality-of-life benefits over conventional treatment modalities. Of available antiandrogens, monotherapy with bicalutamide has been most extensively evaluated. Combined data from 2 studies at a median follow-up time of 6.3 years revealed no statistically significant difference in overall survival between bicalutamide 150-mg monotherapy and castration in patients with nonmetastatic locally advanced disease. In patients with metastatic disease, there was a statistically significant difference (6 weeks) in overall survival in favor of castration. Bicalutamide monotherapy is associated with significant quality-of-life benefits (sexual interest and physical capacity), with preliminary data suggesting that the risk of osteoporosis may also be reduced by bicalutamide 150-mg monotherapy compared with castration. In general, bicalutamide is well tolerated, with a predictable adverse-effect profile. Breast pain (40%) and gynecomastia (49%) are the most common adverse events seen during monotherapy with this drug. In summary, the availability of bicalutamide 150-mg monotherapy broadens treatment options for men with locally advanced prostate cancer, offering a viable and attractive alternative to castration in this patient population. Ongoing studies will determine the role of bicalutamide in the treatment of localized disease.

The role of diethylstilbestrol in the treatment of prostate cancer

OBJECTIVES

Diethylstilbestrol administration was a classic form of androgen deprivation therapy (ADT) that gradually fell out of favor because of its cardiovascular toxicity, economic disinterest on the part of manufacturers, and the emergence of novel therapeutic agents with a superior safety profile. The cost of contemporary agents and the efficacy of diethylstilbestrol (DES) have perpetuated the evaluation of this agent, especially in the circumstance of early hormone-refractory (clinical stage D2.5) disease. The objective of this study is to evaluate the status of DES-based therapies, and assess their efficacy and toxicity as a viable form of ADT.

METHODS

Current research from single-institution and group studies, as well as basic scientific investigations related to DES, were assessed with regard to the population studied, dosage, criteria for response, response rate, duration of response, and toxicity.

RESULTS

Contemporary basic research has demonstrated a direct apoptotic effect of DES on prostate cancer cells. There is also evidence to support the ability of DES to suppress testosterone production at extratesticular sites and inhibit dihydroepiandrosterone sulfate serum levels. Contemporary cooperative group trials for stage D2 disease incorporating a DES arm have demonstrated therapeutic efficacy and equivalence to orchiectomy, which is marred by significant cardiovascular toxicity. In smaller single-institution studies (n = 17 to 38) of patients with D2.5 disease, an average response rate of 55% is noted with a mean time to clinical progression of 6.4 months (2 to 18). Cardiovascular toxicity occurred in 10% to 30% of patients, with events including deep vein thrombosis, myocardial infarction, and transient ischemic attack. Edema and gynecomastia was also noted. Strategies to reduce thromboembolic events, such as dose reduction or the use of warfarin sodium were unsuccessful, whereas the use of low-dose aspirin (100 mg daily) resulted in only 1 of 38 vascular events.

CONCLUSIONS

In contemporary studies of DES as an agent for ADT in D2.5 patients, a reasonable response rate (40% to 60%) of modest duration (5 to 8 months) is noted. Cardiovascular complications still persist, requiring the development of safe, effective antithrombolic therapy to take advantage of this phenomenon.

Survival of patients who had salvage castration after failure on bicalutamide monotherapy for stage (D2) prostate cancer

Patients with hormone-naive stage D2 prostate cancer often benefit from castration. This treatment, however, frequently produces many unacceptable physical and psychological side effects, especially in younger and sexually active patients. Bicalutamide is an oral antiandrogen with excellent tolerance and preservation of sexual function. Three institutions participated in phase II and III trials of bicalutamide monotherapy (50 mg daily) as primary therapy in hormone-naive patients with stage D2 prostate cancer. Upon bicalutamide failure, all patients underwent castration and were followed until death. Fifty-four patients received bicalutamide 50 mg orally once a day. One patient (2%) had complete response, 9 patients (17%) had partial response, and 27 patients (50%) had stable disease. Seventeen patients (31%) had progressive disease. The median time to bicalutamide failure was 47.4 weeks, 70.5 weeks for the responders vs. 25.4 weeks for the nonresponders (p < 0.001). The median survival time after the sequential use of bicalutamide and castration was 119.2 weeks for all 54 patients, 162.0 weeks for the responders, and 73.5 weeks for nonresponders (p < 0.0001). The median survival time after initiation of castration was 71.1 weeks for all 54 patients, 91.4 weeks for bicalutamide responders, and 42.1 weeks for nonresponders (p < 0.01). In hormone-naive patients with stage D2 prostate cancer, sequential treatment with bicalutamide monotherapy followed by castration upon failure may produce survival time within the range reported for initial treatment with castration. Thus, considering the favorable quality of life profile of bicalutamide, further studies are needed to define the role of sequential hormonal therapy in younger sexually active patients.

[Anemia and neoadjuvant hormone therapy in radical surgery of localized cancer of the prostate]

RATIONALE

Erythropoiesis is stimulated by androgens either through a direct action on bone marrow cells or through increased erythropoietin production. Androgen deprivation is a known cause for anaemia. The aim of this study was to evaluate the effect of neoadjuvant hormone therapy prior to radical surgery on haemoglobin (Hb) and haematocrit (Ht) levels in localised prostate cancer.

MATERIAL AND METHOD

47 patients with clinical localised prostate cancer were given LH-RH analogs plus flutamide for complete androgenic blockade (CAB) for at least 3 months prior to radical prostatectomy. A blood profile was obtained prior to start CAB and 3 months after therapy, and peri-operative transfusional requirements were evaluated. To assess any significant changes. Student's t test was used in the statistical analysis of paired data.

RESULTS

In our study all patients (100%) showed decreased Hb and Ht levels after 3 months on CAB. Mean decline for Hb was 1.9 g/dL (range 1.6-2.2) p:0.0001, and for Ht 5.8% (range 4.8-6.8) p:0.0001. Hb was lower than 12 g/dL in 10.6% patients after hormone therapy and anaemia results were normocytic-normochromic. 60% patients needed peri-operative blood transfusion, 2 units of packed cells on average.

CONCLUSIONS

Neoadjuvant CAB prior to radical prostatectomy results in a significant decline of Hb and Ht levels after 3 months treatment. Such decline may contribute to increase peri-operative transfusional requirements in a group of patients undergoing aggressive surgery which in itself involves a significant blood loss.

Prospective trial of the herbal supplement PC-SPES in patients with progressive prostate cancer

PURPOSE

PC-SPES is an herbal supplement for which there are anecdotal reports of anti-prostate cancer activity. This phase II study was undertaken to assess the efficacy and toxicity of PC-SPES in prostate cancer patients.

PATIENTS AND METHODS

Thirty-three patients with androgen-dependent prostate cancer (ADPCa) and 37 patients with androgen-independent prostate cancer (AIPCa) were treated with PC-SPES at a dose of nine capsules daily. Clinical outcome was assessed with serial serum prostate-specific androgen (PSA) level measurement and imaging studies.

RESULTS

One hundred percent of ADPCa patients experienced a PSA decline of >/= 80%, with a median duration of 57+ weeks. No patient has developed PSA progression. Thirty-one patients (97%) had declines of testosterone to the anorchid range. Two ADPCa patients had positive bone scans; both improved. One patient with a bladder mass measurable on computed tomography scan experienced disappearance of this mass. Nineteen (54%) of 35 AIPCa patients had a PSA decline of >/= 50%, including eight (50%) of 16 patients who had received prior ketoconazole therapy. Median time to PSA progression was 16 weeks (range, 2 to 69+ weeks). Of 25 patients with positive bone scans, two had improvement, seven had stable disease, 11 had progressive disease, and five did not have a repeat bone scan because of PSA progression. Severe toxicities included thromboembolic events (n = 3) and allergic reactions (n = 3). Other frequent toxicities included gynecomastia/gynecodynia, leg cramps, and grade 1 or 2 diarrhea.

CONCLUSION

PC-SPES seems to have activity in the treatment of both ADPCa and AIPCa and has acceptable toxicity. Further study is required to determine whether its effects exceed those expected with estrogen therapy.

Hormone therapy of prostate cancer: is there a role for antiandrogen monotherapy?

Androgen suppressive maneuvers still represent the gold standard for prostate cancer patients. However, they are associated with side effects (fatigue, sexual impotence, hot flushes, anemia, anxiety, depression and osteoporosis) all of which have a negative impact on quality of life. Nonsteroidal antiandrogens compete with dihydrotestosterone for the linkage of its own receptors. These compounds are commonly used in combination with suppressive maneuvers. However, there is a growing experience with them as monotherapy, based on the possibility to spare gonadal function and therefore prevent the effects related to its suppression. Many studies have demonstrated the feasibility and safety of this approach, which can represent a valuable alternative to suppressive maneuvers for patients wishing to retain sexual function, especially for those without distant metastases. Unfortunately, none of the comparative studies performed so far had the power to detect the equivalence between monotherapy and castration.

Stilboestrol plus adrenal suppression as salvage treatment for patients failing treatment with luteinizing hormone-releasing hormone analogues and orchidectomy

OBJECTIVE

To investigate the efficacy of low-dose stilboestrol (SB) with hydrocortisone in patients with advanced prostate cancer refractory to androgen suppression.

PATIENTS AND METHODS

Thirty-four consecutive patients (median age 70 years, range 51-83) with metastatic disease who progressed on hormone therapy, as shown by recurrent/worsening symptoms and an increase in prostate-specific antigen (PSA) level, were recruited and discontinued hormonal treatment before starting SB. Patients received SB (1 mg/day) combined with hydrocortisone (40 mg/day). In an attempt to reduce the incidence of thrombo-embolic events, aspirin (75 mg/day) was also added.

RESULTS

Stilboestrol was the second-line treatment in 19 patients and the third or fourth in 15. The median (range) duration of treatment with SB was 5 (0.5-21) months and the median follow-up 7.5 months, with 18 patients still alive and 14 still on treatment. Of 29 symptomatic patients, 24 had symptomatic improvement and five had no clear benefit; the median duration of benefit was 6 (2-21) months. The PSA level decreased by 0-50% in six patients, by 50-90% in 13 and by > 90% in eight, while there was symptomatic improvement in these three categories in five, 11 and seven patients, respectively. The median times to PSA nadir and progression were 4 and 6 months, respectively. Some thrombo-embolic events and fluid retention occurred but overall the treatment was well tolerated.

CONCLUSION

Low-dose SB with hydrocortisone is effective in refractory prostate cancer, although there is some toxicity. Randomized studies against hydrocortisone or SB alone are needed to establish the cost/benefit ratio of this combination.

Single-therapy androgen suppression in men with advanced prostate cancer: a systematic review and meta-analysis

PURPOSE

To compare luteinizing hormone-releasing hormone (LHRH) agonists with orchiectomy or diethylstilbestrol, and to compare antiandrogens with any of these three alternatives.

DATA SOURCES

A search of the MEDLINE, Cancerlit, EMBASE, and Cochrane Library databases from 1966 to March 1998 and Current Contents to 24 August 1998 for articles comparing the outcomes of the specified treatments. The search was limited to studies on prostatic neoplasms in humans. Total yield was 1477 studies.

STUDY SELECTION

Reports of efficacy outcomes were limited to randomized, controlled trials. Twenty-four trials involving more than 6600 patients, phase II studies that reported on withdrawals from therapy (the most reliable indicator of adverse effects), and all studies reporting on quality of life were abstracted.

DATA EXTRACTION

Two independent reviewers abstracted each article by following a prospectively designed protocol. The meta-analysis combined data on 2-year overall survival by using a random-effects model and; reported results as a hazard ratio relative to orchiectomy.

DATA SYNTHESIS

Ten trials of LHRH agonists involving 1908 patients reported no significant difference in overall survival. The hazard ratio showed LHRH agonists to be essentially equivalent to orchiectomy (hazard ratio, 1.1262 [corrected] [95% CI, 0.915 to 1.386]). There was no evidence of difference in overall survival among the LHRH agonists, although CIs were wider for leuprolide (hazard ratio, 1.0994 [CI, 0.207 to 5.835]) and buserelin (hazard ratio, 1.1315 [CI, 0.533 to 2.404]) than for goserelin (hazard ratio, 1.1172 [CI, 0.898 to 1.390]). Evidence from 8 trials involving 2717 patients suggests that nonsteroidal antiandrogens were associated with lower overall survival. The CI for the hazard ratio approached statistical significance (hazard ratio, 1.2158 [CI, 0.988 to 1.496]). Treatment withdrawals were less frequent with LHRH agonists (0% to 4%) than with nonsteroidal antiandrogens (4% to 10%).

CONCLUSIONS

Survival after therapy with an LHRH agonist was equivalent to that after orchiectomy. No evidence shows a difference in effectiveness among the LHRH agonists. Survival rates may be somewhat lower if a nonsteroidal antiandrogen is used as monotherapy.

Antiandrogens in prostate cancer

Antiandrogens competitively inhibit ligand binding to the androgen receptor (AR), and are used therapeutically in prostate cancer patients. The AR functions as a ligand dependent transcription factor that transduces androgen binding into increased transcription of androgen dependent genes. AR blockade induces programmed cell death in the vast majority of malignant and benign prostate cancer cells that have not previously been exposed to androgen ablation. The antiandrogens are divided structurally into the steroidal and non steroidal agents. The biological effects of the steroidal versus nonsteroidal agents are distinguished by differences in their effects on serum testosterone levels, and by their activity at receptors other than the androgen receptor. There is extensive clinical experience in the palliative and curative therapy of prostate cancer using antiandrogens as monotherapy or antiandrogens in combination with luteinizing hormone agonists or surgical castration. Prolonged therapy with antiandrogens selects for mutations in the AR that change the AR ligand specificity and permits stimulation by ligands that are usually inhibitory. These mutations give insight into one of the means by which prostate cancer progresses despite antiandrogen therapy, and also helps to explain the antiandrogen withdrawal syndrome. Areas of active research that may affect the future use of antiandrogens include the ongoing evaluation of antiandrogens in combination with 5 alpha reductase inhibitors to achieve AR blockade without inducing castrate testosterone levels. There is also interest in developing selective androgen receptor modulators (SARM) that can achieve AR blockade without causing the increased testosterone levels produced by the nonsteroidal antiandrogens currently in use.

Immediate hormonal therapy compared with observation after radical prostatectomy and pelvic lymphadenectomy in men with node-positive prostate cancer

BACKGROUND

Because the optimal timing of the institution of antiandrogen therapy for prostate cancer is controversial, we compared immediate and delayed treatment in patients who had minimal residual disease after radical prostatectomy.

METHODS

Ninety-eight men who underwent radical prostatectomy and pelvic lymphadenectomy and who were found to have nodal metastases were randomly assigned to receive immediate antiandrogen therapy, with either goserelin, a synthetic agonist of gonadotropin-releasing hormone, or bilateral orchiectomy, or to be followed until disease progression. The patients were assessed quarterly during the first year and then semiannually.

RESULTS

After a median of 7.1 years of follow-up, 7 of 47 men who received immediate antiandrogen treatment had died, as compared with 18 of 51 men in the observation group (P=0.02). The cause of death was prostate cancer in 3 men in the immediate-treatment group and in 16 men in the observation group (P<0.01). At the time of the last follow-up, 36 men in the immediate-treatment group (77 percent) and 9 men in the observation group (18 percent) were alive and had no evidence of recurrent disease, including undetectable serum prostate-specific antigen levels (P<0.001). In the observation group, the disease recurred in 42 men; 13 of the 36 who were treated had a complete response to local treatment or hormonal therapy (or both), 16 died of prostate cancer, and 1 died of another disease. The remaining men in this group were alive with progressive disease at the time of the last follow-up or had had a recent relapse. Except for the treatment group (immediate therapy or observation), no clinical or histologic characteristic significantly influenced the outcome.

CONCLUSIONS

Immediate antiandrogen therapy after radical prostatectomy and pelvic lymphadenectomy improves survival and reduces the risk of recurrence in patients with node-positive prostate cancer.

Gender and vascular reactivity

Estrogen receptors are found on vascular endothelial and smooth muscle cells; their expression is influenced by exposure to the hormone. Estrogen receptors influence non-genomic events, which are rapid in onset and genomic events, which are longer acting responses. Estrogens affect vascular tone indirectly by modulating release of endothelium-derived vasoactive factors and directly by modulating intracellular calcium in vascular smooth muscle cells. Estrogens indirectly affect thrombotic events and inflammation by altering platelet aggregation and leukocyte adherence and migration, respectively. Estrogens also influence production of mitogens which, when released at sites of vascular injury, affect vascular remodeling. Although estrogens initiate vascular responses, genomic sex may influence and/or limit expression of estrogen receptors and therefore actions of sex steroid hormones throughout the vasculature.

Use of PC-SPES, a commercially available supplement for prostate cancer, in a patient with hormone-naive disease

OBJECTIVES

PC-SPES, an over-the-counter supplement, is actually a combination of eight different herbs. It is being used by patients to treat cancer of the prostate at different stages of the disease and has been commercially available since November 1996. It has been observed to dramatically decrease prostate-specific antigen (PSA) values in several patients; however, its out-of-pocket cost ($162 to $486/mo) and potential side effects must be weighed against its potential objective benefits. We reviewed its use in 1 patient.

METHODS

A patient with clinically localized prostate cancer (T1c) with a PSA of 8.8 ng/mL, who decided to delay any conventional treatment, began treatment with 9 PC-SPES capsules/day.

RESULTS

After 3 weeks, his PSA dropped to 1.4 ng/mL and after a total of 8 weeks, his PSA was less than 0.1 ng/mL (undetectable). He has continued on a maintenance dose of 6 capsules per day, decreasing to 4 capsules per day, with a continuing undetectable PSA. During this time the patient also experienced a number of strong estrogenic effects: loss of libido, erectile dysfunction, extreme breast enlargement and tenderness, reduction in overall body hair, pitting edema, and a significant drop in his lipoprotein (a) level (from 46 to 11 mg/dL).

CONCLUSIONS

PC-SPES may provide additive advantages (or disadvantages) over prescribed hormonal treatments but must be compared with other hormonal and nonhormonal treatments in clinical trials with hormone-sensitive and -insensitive patients with prostate cancer to determine its future use or nonuse.

Bicalutamide monotherapy versus flutamide plus goserelin in prostate cancer patients: results of an Italian Prostate Cancer Project study

PURPOSE

To compare the efficacy of bicalutamide monotherapy to maximal androgen blockade (MAB) in the treatment of advanced prostatic cancer.

PATIENTS AND METHODS

Previously untreated patients with histologically proven stage C or D disease (American Urological Association Staging System) were randomly allocated to receive either bicalutamide or MAB. After disease progression, patients treated with bicalutamide were assigned to castration. The primary end point for this trial was overall survival. Secondary end points included response to treatment, disease progression, treatment safety, quality-of-life (QOL), and sexual function.

RESULTS

A total of 108 patients received bicalutamide and 112 received MAB. There was no difference in the percentage of patients whose prostate-specific antigen returned to normal levels. At the time of the present analysis (median follow-up time, 38 months; range, 1 to 60 months), 129 patients progressed and 89 died. There was no difference in the duration of either progression-free survival or overall survival. However, a survival trend favored bicalutamide in stage C disease but MAB in stage D disease. Overall and subgroup trends were confirmed by multivariate analysis. Serious adverse events and treatment discontinuations were more common in patients receiving MAB (P =.08 and P =.04, respectively). Fewer patients in the bicalutamide group complained of loss of libido (P =. 01) and of erectile dysfunction (P =.002). Significant trends favored bicalutamide-treated patients also with respect to their QOL, namely relative to social functioning, vitality, emotional well-being, and physical capacity.

CONCLUSION

Bicalutamide monotherapy yielded comparable results relative to standard treatment with MAB, induced fewer side effects, and produced a better QOL.

Controversies in the management of advanced prostate cancer

For advanced prostate cancer, the main hormone treatment against which other treatments are assessed is surgical castration. It is simple, safe and effective, however it is not acceptable to all patients. Medical castration by means of luteinizing hormone-releasing hormone (LH-RH) analogues such as goserelin acetate provides an alternative to surgical castration. Diethylstilboestrol, previously the only non-surgical alternative to orchidectomy, is no longer routinely used. Castration reduces serum testosterone by around 90%, but does not affect androgen biosynthesis in the adrenal glands. Addition of an anti-androgen to medical or surgical castration blocks the effect of remaining testosterone on prostate cells and is termed combined androgen blockade (CAB). CAB has now been compared with castration alone (medical and surgical) in numerous clinical trials. Some trials show advantage of CAB over castration, whereas others report no significant difference. The author favours the view that CAB has an advantage over castration. No study has reported that CAB is less effective than castration. Of the anti-androgens which are available for use in CAB, bicalutamide may be associated with a lower incidence of side-effects compared with the other non-steroidal anti-androgens and, in common with nilutamide, has the advantage of once-daily dosing. Only one study has compared anti-androgens within CAB: bicalutamide plus LH-RH analogue and flutamide plus LH-RH analogue. At 160-week follow-up, the groups were equivalent in terms of survival and time to progression. However, bicalutamide caused significantly less diarrhoea than flutamide. Withdrawal and intermittent therapy with anti-androgens extend the range of treatment options.

Androgen deprivation for prostatic carcinoma: a rationale for choosing components

Ever since prostatic carcinoma was discovered to be dependent on the hormone androgen for its proliferation, androgen deprivation has been the treatment of choice for advanced cases of prostate cancer. Originally, treatment was limited to surgical castration or estrogen therapy. However, the introduction of luteinizing hormone-releasing hormone analogues, antiandrogens, and newer treatment modalities, such as combined androgen blockade, has made choosing a treatment strategy more complex. Assuming that each modality is equally effective, emphasis should be placed on increasing patient tolerance and compliance by the use of long-acting, nontoxic treatments with simple dosing regimens and minimal side effects. This review focuses on the factors influencing the final choice of treatment strategy.

Casodex (bicalutamide) 150-mg monotherapy compared with castration in patients with previously untreated nonmetastatic prostate cancer: results from two multicenter randomized trials at a median follow-up of 4 years

OBJECTIVES

To compare the efficacy, tolerability, and quality of life benefits of bicalutamide (Casodex) 150-mg/day monotherapy and castration in previously untreated nonmetastatic (M0) advanced prostate cancer.

METHODS

A total of 480 patients with Stage T3/T4 nonmetastatic disease randomly received oral bicalutamide 150 mg/day or castration (either bilateral orchiectomy or goserelin acetate [Zoladex] 3.6 mg every 28 days) in a 2:1 ratio in two open multicenter studies (studies 306 and 307). The design of these studies was similar to allow a pooled analysis.

RESULTS

In the combined survival analysis, at median follow-up of 202 and 205 weeks in studies 306 and 307, respectively, with 31% of the cases resulting in death, bicalutamide 150-mg monotherapy was statistically equivalent to castration; the risk of death from any cause was 7% less with bicalutamide than with castration (hazard ratio [HR] = 0.93). Data on time to treatment failure and objective progression could not be pooled, as results for these end points differed between the trials. In study 306, bicalutamide 150-mg monotherapy increased time to objective progression (HR = 0.58; P = 0.033) and treatment failure (HR = 0.66; P = 0.074), whereas in study 307, time to progression (HR = 1.35; P = 0.0471) and treatment failure (HR = 1.24; P = 0.097) favored castration. Bicalutamide therapy showed significant advantages over castration for both sexual interest (P = 0.029) and physical capacity (P = 0.046). Bicalutamide 150-mg monotherapy was well tolerated.

CONCLUSIONS

Bicalutamide 150-mg monotherapy provides a similar survival outcome to castration in previously untreated patients with nonmetastatic advanced prostate cancer and confers statistically significant benefits over castration with respect to sexual interest and physical capacity.