The effects of aminoglutethimide and hydrocortisone, alone and combined, on androgen levels in post-orchiectomy prostatic cancer patients

Roles for the backdoor pathway of androgen metabolism in prostate cancer response to castration and drug treatment

Almost all men who present with advanced prostate cancer (CaP) and many men who fail potentially curative therapy are treated with androgen deprivation therapy (ADT). ADT is not curative and CaP recurs as the lethal phenotype. The goal of this review is to describe the evolution of adrenal androgen blockade, how new androgen measurement methods have furthered understanding of androgen metabolism, and how further understanding of the backdoor pathway of androgen metabolism may lead to interventions that extend survival even more.

TREATMENT WITH PREDNISOLONE OF HORMONE-REFRACTORY PROSTATE CANCER

Fifteen patients 60 to 80 years old (a mean of 72 years) with hormone-refractory prostate cancer were treated with low dose prednisolone. All patients had previously undergone hormone therapy. Prostate specific antigen (PSA) values decreased in 11 cases (73%), of which 4 had PSA decreases of 50% or greater. Serum levels of DHEAS significantly decreased at 4 and 8 weeks after treatment (both intervals were p < 0.05 vs pretreatment). Of 8 patients with bone metastasis evaluation, 2 (25%) showed improvement of the lesion. In 5 patients (33%), relief of pain was observed one month after starting prednisolone. The one-year survival rate was 58%. The side effects were mild and manageable in an outpatient clinic.

Hormonal impact of the 17alpha-hydroxylase/C(17,20)-lyase inhibitor abiraterone acetate (CB7630) in patients with prostate cancer

A series of three dose escalating studies were conducted to investigate the ability of the 17α-hydroxylase/C_17,20-lyase inhibitor abiraterone acetate, to cause maximum suppression of testosterone synthesis when delivered to castrate and noncastrate males with prostate cancer. Study A was a single dose study in castrate males. Study B was a single dose study in noncastrate males and study C was a multiple dose study in noncastrate males. The drug was given orally in a once-daily dose and blood samples taken to assess pharmacokinetic (PK) parameters and hormone levels in all patients. The study drug was well tolerated with some variability in PKs. Suppression of testosterone levels to <0.14 nmol l⁻¹ was seen in four out of six castrate males treated with a single dose of 500 mg. At 800 mg given days 1–12 in noncastrate males, target suppression was achieved in three out of three patients, but a two- to three-fold increase of Luteinising Hormone (LH) levels in two out of three patients overcame suppression within 3 days. All patients in the multiple dose study developed an abnormal response to a short Synacthen test by day 11, although baseline cortisol levels remained normal. This is the first report of the use of a specific 17α-hydroxylase/_17,20-lyase inhibitor in humans. Repeated treatment of men with intact gonadal function with abiraterone acetate at a dose of 800 mg can successfully suppress testosterone levels to the castrate range. However, this level of suppression may not be sustained in all patients due to compensatory hypersecretion of LH. The enhanced testosterone suppression achieved in castrate men merits further clinical study as a second-line hormonal treatment for prostate cancer. Adrenocortical suppression may necessitate concomitant administration of replacement glucocorticoid.

An Evaluation of Intermediate-Dose Ketoconazole in Hormone Refractory Prostate Cancer

OBJECTIVES

The management of hormone refractory prostate cancer remains controversial. Among the options, second-line hormonal therapy is commonly used. We investigated the efficacy of ketoconazole, an inhibitor of testicular and adrenal androgen biosynthesis, for treating patients with advanced hormone refractory prostate cancer.

METHODS

The study comprised 38 patients with progressive disease despite combined androgen blockade. Treatment consisted of intermediate-dose ketoconazole (300mg three times daily) and replacement hydrocortisone. Patients were monitored clinically and with serial psa measurements every 3 months. the principal endpoint was psa response.

RESULTS

Of the 38 patients, 21 (55.3%) showed a decrease in PSA >50% (95% confidence interval 38.3%-71.4%) with a median duration of 6 months (range 3-48 months). A PSA reduction >50% was seen in 21 of 34 patients (61.8%) with established metastases. Thirteen patients (34.2%), all of whom had metastases, exhibited a PSA decrease >80% (95% confidence interval 19.6%-51.4%) with a median duration of 9 months (range 3-48 months). Age, PSA at diagnosis, Gleason score and bone scan result were not significantly associated with response to ketoconazole treatment in univariate or multivariate analyses. For the entire study group, the median time to progression was 5 months (range 0-27 months) and the median survival was 12 months (range 3-48 months). Overall, 12 patients (31.6%) reported toxicity related to intermediate-dose ketoconazole but only 6 patients (15.8%) discontinued therapy due to intolerable side effects.

CONCLUSION

It is apparent from this study that a reasonable percentage of patients failing standard hormonal therapy respond favourably to intermediate-dose ketoconazole and that toxicity is mild. In the absence of studies demonstrating better survival with chemotherapy, we believe that a trial of ketoconazole should be considered when progression occurs on hormone therapy.

Corticosteroid-induced inhibition of adrenal androgen production in selected patients with prostate cancer

OBJECTIVE

To determine the effect of administration of corticosteroids on adrenal androgen production and the serologic markers of prostate cancer.

METHODS

Six patients with prostate cancer who had a serum testosterone concentration that exceeded 20 ng/dL despite treatment with medical or surgical castration were treated with dexamethasone. All patients were asymptomatic, but four were demonstrating progressive increases in serum prostate-specific antigen (PSA) concentrations. Dexamethasone, 1 mg at bedtime, was given initially and then increased to 1 mg twice daily if serum testosterone concentrations remained > or =10 ng/dL. The effect of treatment on PSA concentration was monitored.

RESULTS

The mean testosterone concentration (and standard error of the mean) was 47.5 +/- 7.9 ng/dL before administration of dexamethasone; this decreased to 5.2 +/- 3.0 ng/dL during therapy (P = 0.002). The effect was rapid (overnight) and sustainable (for 6 months). Although the duration of follow-up is limited, PSA concentrations generally stabilized (23.5 +/- 6.1 ng/mL at baseline in comparison with 15.6 +/- 1.1 ng/mL approximately 2 months after initiation of dexamethasone therapy; P = 0.24). Two patients required 1 mg of dexamethasone twice daily to suppress serum testosterone levels to <10 ng/dL.

CONCLUSION

Administration of corticosteroids in a manner opposing the normal circadian glucocorticoid production effectively and rapidly decreases adrenal androgen production in patients with prostate cancer treated with orchiectomy or luteinizing hormone-releasing hormone agonists. This reduction of androgen production was generally associated with a decrease or stabilization of PSA concentrations in all patients with increased PSA levels. Overnight dexamethasone suppression testing is useful in determining the minimal effective dose.

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.

Secondary hormonal manipulations in hormone refractory prostate cancer

Hormone refractory prostate cancer is clinically heterogeneous, and many patients retain sensitivity to subsequent hormonal manipulations, even after combined androgen blockage. Antiandrogen withdrawal is a mandatory first step. Subsequent treatment with an alternate antiandrogen, adrenal androgen inhibitor (such as ketoconazole), or glucocorticoid may provide both subjective and objective clinical benefit in up to 65% of patients.

P450-dependent enzymes as targets for prostate cancer therapy

Metastatic prostate adenocarcinoma is a leading cause of cancer-related deaths among men. First line treatment is primarily aimed at blocking the synthesis and action of androgens. As primary endocrine treatment, androgen deprivation is usually achieved by orchidectomy or LHRH analogues, frequently combined with androgen receptor antagonists in order to block the residual adrenal androgens. However, nearly all the patients will eventually relapse. Available or potential second line therapies include, among others, alternative endocrine manipulations and chemotherapy. Cytochrome P450-dependent enzymes are involved in the synthesis and/or degradation of many endogenous compounds, such as steroids and retinoic acid. Some of these enzymes represent suitable targets for the treatment of prostate cancer. In first line therapy, inhibitors of the P450-dependent 17,20-lyase may achieve a maximal androgen ablation with a single drug treatment. Ketoconazole at high dose blocks both testicular and adrenal androgen biosynthesis but its side-effects, mainly gastric discomfort, limit its widespread use. A series of newly synthesized, more selective, steroidal 17,20-lyase inhibitors related to 17-(3-pyridyl)androsta-5,16-dien-3beta-ol, may open new perspectives in this field. In prostate cancer patients who relapse after surgical or medical castration, therapies aiming at suppressing the remaining adrenal androgen biosynthesis (ketoconazole) or producing a medical adrenalectomy (aminoglutethimide+hydrocortisone) have been used, but are becoming obsolete with the generalization of maximal androgen blockade in first line treatment. The role of inhibition of aromatase in prostate cancer therapy, which was postulated for aminoglutethimide, could not be confirmed by the use of more selective aromatase inhibitors, such as formestane. An alternative approach is represented by liarozole fumarate (LIA), a compound that blocks the P450-dependent catabolism of retinoic acid (RA). In vitro, it enhances the antiproliferative and differentiation effects of RA in cell lines that express RA metabolism, such as F9 teratocarcinoma and MCF-7 breast carcinoma cells. In vivo, monotherapy with LIA increases RA plasma levels and, to a greater extent, endogenous tissue RA levels leading to retinoid-mimetic effects. In the rat Dunning prostate cancer models, it inhibits the growth of androgen-independent as well as androgen-dependent carcinomas relapsing after castration. Concurrently, changes in the pattern of cytokeratins characteristic of increased differentiation were observed. Early clinical trials show that LIA, in second or third line therapy in metastatic prostate cancer, induces PSA responses in about 30% of unselected patients. In some patients regression of soft tissue metastasis ha been observed. In a subgroup of patients, an important relief of metastatic bone pain was also noted.

Prostate specific antigen levels and clinical response to low dose dexamethasone for hormone-refractory metastatic prostate carcinoma

BACKGROUND

It has been suggested that suppression of adrenal androgens may provide benefit to patients with metastatic prostate cancer refractory to initial hormonal therapy (e.g., orchiectomy).

METHODS

The records of 38 patients with metastatic prostate cancer that had progressed after orchiectomy who were placed subsequently on low dose dexamethasone (DXM) with no other concurrent therapy (36 patients received 0.75 mg twice daily and two received 0.75 mg three times daily) were reviewed. Symptomatic status, prostate specific antigen (PSA) measurements, and available radiographic assessments were recorded. Bone scans were reviewed by an independent, blinded evaluator.

RESULTS

Symptomatic improvement was experienced by 24 patients (63%), 20 (83%) of whom also had decreases in PSA. Prostate specific antigen values decreased in 30 patients (79%) with decreases 50% or greater and 80% or greater in 23 (61%) and 13 (34%) patients, respectively. Of the 23 patients with PSA decreases 50% or greater, 8 (35%) had radiographic evidence of disease regression, 5 (22%) were stable, 7 (30%) had disease progression, and 3 (13%) did not have serial radiographic exams. Flutamide was discontinued shortly before DXM treatment for 2 of the 23 patients.

CONCLUSIONS

Low dose DXM may produce important symptomatic improvement and decreased PSA levels in the majority of patients with hormone-refractory prostate cancer. In addition, a substantial percentage of those patients with decreases in PSA also will have radiographic evidence of disease regression. These results suggest the need for additional prospective controlled studies of DXM as a therapy for hormone-refractory prostate cancer.

A case for synchronous reduction of testicular androgen, adrenal androgen and prolactin for the treatment of advanced carcinoma of the prostate

The present study was undertaken mainly to investigate whether prolactin manipulation combined with maximal androgen blockage improves the effectiveness of treatment in advanced prostatic cancer. The efficacy of oral hydrocortisone as an alternative to commercial anti-androgens in reducing the adrenal androgens, and of bromocriptine in reducing the prolactin level were also examined. A consecutive series of 30 patients with untreated and advanced prostatic cancer were entered into a three-arm prospective randomised trial. 10 patients received subcapsular orchiectomy alone (arm 1), another 10 had subcapsular orchiectomy plus flutamide (arm 2), and the remaining 10 had subcapsular orchiectomy plus oral hydrocortisone and bromocriptine (arm 3). Clinical and biochemical parameters, including trans-rectal ultrasound-determined prostatic volumes, hormonal profiles and radionuclide bone scan were evaluated at regular intervals. At 12 months, serum testosterone was reduced by more than 90% in all arms, however, maximum suppression of androstenedione, prolactin, and reduction of prostatic volumes were only observed in arm 3; this was reflected by the significant improvement in clinical response in arm 3 compared with other arms. This study suggests that a combined maximal suppression of androgens and prolactin offers a significant improvement in response over conventional treatments without prolactin suppression in the treatment of advanced prostatic cancer. Importantly, a better clinical outcome in arm 3 was still apparent at the end of 36 months.

Prostate cancer

Prostate cancer is the most common noncutaneous malignancy diagnosed in American men, and in 1994 it will pass lung cancer as the most common cancer diagnosed in the United States, with an estimated 200,000 new cases. The molecular biology of prostate carcinogenesis is rapidly advancing, and it is clear that, to a degree, prostate cancer is a heritable disease. The use of serum prostate-specific antigen (PSA) as a screening tool has been widely accepted by the medical community, although the evidence to support the efficacy of screening is not yet available. The curative approaches to organ-confined, clinically localized prostate cancer include radiation therapy, radical prostatectomy, and close observation in selected patients. The absence of well-designed clinical trials contributes to the confusion surrounding which curative treatment is the best option in individual patients. The standard approach to patients with evidence of extracapsular spread without distant metastases has been external-beam radiotherapy, although the results with radiation therapy alone in these patients has left considerable room for improvement. Innovative combined-modality approaches are currently being investigated at a number of institutions for these poor-prognosis patients. Three-dimensional conformal radiation therapy is currently being investigated at multiple institutions and offers some hope for improved results. The treatment of metastatic disease remains hormonal manipulation, although the exact nature of optimal androgen deprivation is currently a matter of considerable debate. In patients with hormone-refractory disease newer regimens using novel chemotherapy regimens offer some promise.

Aromatase inhibitors in malignant diseases of aging

Aromatase inhibition is an established endocrine treatment modality in postmenopausal breast cancer and is currently considered as an interesting experimental treatment approach in other malignant conditions such as endometrial carcinomas and prostatic cancer. While the 'classic' aromatase inhibitor aminoglutethimide causes many adverse effects that makes it unfit for use in elderly patients, several novel aromatase inhibitors with minimal adverse effects are currently being investigated. These drugs may provide important new tools in the endocrine treatment of malignant diseases in aging patients.

Aromatase inhibition: 4-hydroxyandrostenedione (4-OHA, CGP 32349) in advanced prostatic cancer

We report the use of the steroidal aromatase inhibitor, 4-hydroxyandrostenedione (4-OHA, CGP 32349), in the management of patients with advanced, hormone resistant, prostatic cancer. Eighteen of 25 patients (72%) showed a subjective response, mainly in the form of pain relief and increased performance. There were no objective improvements. A tumour flare occurred in 17/25 (68%). Detailed endocrine studies were performed during treatment. These showed that suppression of serum oestradiol levels occurred in 19/25 (76%) of patients during treatment with 4-OHA. Serum levels of androstenedione increased in 9/14 patients (64%). Concentration of serum testosterone and 5 alpha-dihydrotestosterone were elevated in 3/14 (21%) and 2/11 (18%) patients respectively. There appeared to be no correlation between response or tumour flare and changes in steroid levels during treatment with 4-OHA. The mechanism of action of 4-OHA in palliating patients with advanced prostatic cancer remains obscure. 4-OHA or its metabolites may be acting on metastatic bone metabolism via effects on oestrogen related osteoclastic and osteoblastic activity. Further investigation of the effects of aromatase inhibitors on prostatic biology, and bone metabolism in patients with metastatic prostate cancer, would appear worthwhile.

4-pregnene-3-one-20 beta-carboxaldehyde: a potent inhibitor of 17 alpha-hydroxylase/C17,20-lyase and of 5 alpha-reductase

The pregnene derivative, 4-pregnene-3-one-20 beta-carboxaldehyde (22-A) was evaluated as an inhibitor of 17 alpha-hydroxylase/C17,20-lyase in rat testicular microsomes and of 5 alpha-reductase in human prostatic homogenates. The effect of the compound in vivo was studied in adult male rats. The 22-A demonstrated potent and competitive inhibition of 17 alpha-hydroxylase and C17,20-lyase with Ki values 8.48 and 0.41 microM, respectively, significantly below the Km values for these two enzymes (33.75 and 4.55 microM). This compound also showed potent inhibition of 5 alpha-reductase with a Ki value of 15.6 nM (Km for this enzyme is 50 nM). By comparison, ketoconazole, a currently studied 17 alpha-hydroxylase/C17,20-lyase inhibitor for the treatment of prostatic cancer, showed less potent inhibition of 17 alpha-hydroxylase (Ki 39.5 microM) and C17,20-lyase (Ki 3.6 microM) and did not inhibit 5 alpha-reductase. Progesterone which has been reported to inhibit the 17 alpha-hydroxylase/C17,20-lyase, did not significantly reduce the production of testosterone by rat testes in vitro in comparison to controls, while the same concentration of 22-A demonstrated a 42% reduction of testosterone biosynthesis. When the adult male rats were injected s.c. with 22-A at 50 mg/day/kg for a 2 week period, the testosterone concentrations in the rat sera were significantly lower than control values (P less than 0.05), whereas serum corticosterone levels did not change. These results suggest that 22-A is a selective potent inhibitor for 17 alpha-hydroxylase and C17,20-lyase, but is more potent for the C17,20-lyase. The compound also inhibits 5 alpha-reductase, and therefore may reduce biosynthesis of testosterone and dihydrotestosterone effectively. Thus, 22-A may be useful in the treatment of problems associated with the androgen excess and prostatic cancer.

Effects of 4-hydroxyandrost-4-ene-3,17-dione and its metabolites on 5 alpha-reductase activity and the androgen receptor

The steroidal aromatase inhibitor, 4-hydroxyandrost-4-ene-3,17-dione (4OHA) and its metabolites, 4-hydroxytestosterone (4OHT), 3 beta,17-dihydroxy-5 alpha-androstan-4-one (metabolite A) and 3 alpha, 17-dihydroxy-5 beta-androstan-4-one (metabolite B) were evaluated as inhibitors of the human prostatic 5 alpha-reductase enzyme and for binding to the rat prostatic androgen receptor. 4OHA and 4OHT were weak inhibitors of 5 alpha-reductase with IC50 values of 15-29 microM. Metabolites A and B had no significant inhibitory activity. 4OHA and metabolites A and B bound weakly to the androgen receptor. The binding affinities (RBA) relative to mibolerone (RBA = 100) were 0.085, 0.485 and 0.016, respectively. However, 4OHT (RBA = 75) was a more potent binder than the endogenous androgen 5 alpha-dihydrotestosterone (RBA = 66). The ability of these metabolites, in particular 4OHT, to bind to the androgen receptor may explain the in vivo androgenic activity of 4OHA.

Comparison of aromatase activity in human prostatic, testicular and placental tissues

The aromatase enzyme was quantified by the release of tritiated water from [1 beta-3H] androstenedione. Tritiated water was released by the crude homogenates in 4 of 18 samples of benign prostatic hyperplasia tissue and one of 5 samples of prostate carcinoma tissue. However, this apparent aromatase activity was not inhibited by 4-hydroxyandrostenedione (0.5 and 5.0 microM), and none of the particulate fractions (100,000 g pellet) prepared from each of the prostatic tissues exhibited aromatase activity. Particulate fractions from rat ovary (n = 3) and human testes (n = 6) displayed significant aromatase activity (mean values of 9.9 and 0.033 nmol estrone formed/g protein/h, respectively). The testicular aromatase was inhibited by aminoglutethimide, 4-hydroxyandrostenedione and CGS 16949A with IC50 values of 6.4, 0.17 and 0.0017 microM, respectively. These are of a similar order to values obtained with the aromatase enzyme from human placental microsomes (14, 0.43 and 0.0075 microM, respectively).

Clinical development of aromatase inhibitors for the treatment of breast and prostate cancer

Numerous aromatase inhibitors are under development for breast cancer treatment. The major aims are to obtain a drug which at its dose of maximum efficacy has no effect on other endocrine systems, has no clinical side-effects and is convenient to administer. During the early clinical stages of development detailed endocrine and pharmacokinetic analyses are a valuable aid in the establishment of a drug's selectivity and its optimum dose, route and frequency of administration. The optimal dose may be defined as the minimum that will achieve maximal and sustained suppression of aromatase activity. This has generally been measured indirectly by comparing the suppression of plasma oestrogen levels at a selection of dosages. This approach has major advantages in speeding dose selection for therapeutic clinical trials. However, it also has some disadvantages including the unproven assumption that clinical response has a direct relationship with the degree of oestrogen suppression. In addition there are technical difficulties of analysis, of wide variability in endocrine response between patients and of demonstrating oestrogen suppression to be equivalent between doses (necessary to show maximal suppression). The direct measurement of aromatase inhibition in vivo by isotopic infusion analysis provides support to these indirect estimates. Its value is shown by our recent results with CGS16949A. The additional value of collating pharmacokinetic and endocrine measurements is apparent from our investigations of 4-hydroxyandrostenedione (4-OHA) and pyridoglutethimide. A consideration of our experience with these inhibitors may be helpful in directing the development of future agents. Whilst the value of aromatase inhibition in breast cancer is established its value in prostatic cancer is in doubt: we have found that 4-OHA is only poorly efficacious in advanced prostatic cancer.

A phase II randomized trial of megestrol acetate or dexamethasone in the treatment of hormonally refractory advanced carcinoma of the prostate

The results of a randomized, multicenter, cooperative group trial evaluating hormonal therapy with either megestrol acetate or dexamethasone in advanced, hormonally refractory prostate cancer are reported. Three of 29 patients (approximately 10%) on the megestrol acetate arm experienced an objective response lasting 41, 84, and 202 days, respectively, whereas two of 29 patients (approximately 7%) on the dexamethasone arm achieved an objective response lasting 359 and 512 days, respectively. Twenty of 29 patients (approximately 69%) on the megestrol acetate arm had stable disease lasting for a median duration of 117 days, whereas 21 of 29 patients (72%) on the dexamethasone arm had stable disease for a median duration of 86 days. Median survival of all patients was 9 months from initiation of treatment. The median survival of all patients on the megestrol acetate arm was 268 days compared to 246 days for patients on the dexamethasone arm (P = 0.2). Neither dexamethasone nor megestrol acetate would seem to be of substantive value in altering the progression of advanced, hormonally refractory prostate cancer.

Aromatase inhibition in advanced prostatic cancer: preliminary communication

We report the results of the first use of a steroidal aromatase inhibitor, 4-hydroxyandrostenedione (4-OHA, CGP 32349), in the palliation of patients with advanced, hormone resistant, prostatic cancer. Twelve of 19 patients (63%), who had relapsed following castration and other therapies, gained significant pain relief following weekly intramuscular injections of 4-OHA. Five patients (31%) experienced a transient 'tumour flare', represented by an increase in bone pain soon after commencing treatment. The mechanism of action of 4-OHA in palliating patients with advanced prostatic cancer is obscure at present, but may represent an important new treatment modality which may lead to greater insight into prostatic biology.

Treatment of stage D2 prostatic cancer refractory to or relapsed following castration plus oestrogens. Comparison of aminoglutethimide plus hydrocortisone with medroxyprogesterone acetate plus hydrocortisone

A total of 59 patients with advanced prostate cancer relapsed from or refractory to castration plus oestrogen were treated in a randomised trial comparing 1000 to 1250 mg aminoglutethimide + 40 mg hydrocortisone (AG + HC) with 500 mg medroxyprogesterone acetate + 40 mg hydrocortisone (MPA + HC). A significantly higher objective response rate and better symptomatic control was noted in patients treated with AG + HC (31%) compared with those treated with MPA + HC (3%). The median time to treatment failure was also significantly longer for patients treated with AG + HC. These findings suggest a role for AG in the treatment of advanced prostate cancer. While both second-line hormone treatment regimens resulted in significant suppression of adrenal androgen secretion, the differences in response rate could not be explained by alterations in peripheral blood hormone levels. AG in high doses may have cellular effects which require further study.