Aminoglutethimide medical adrenalectomy for advanced prostatic carcinoma

Precision medicine applications in prostate cancer

Aided by developments in diagnostics and therapeutics, healthcare is increasingly moving toward precision medicine, in which treatment is customized to each individual. We discuss the relevance of precision medicine in prostate cancer, including gene targets, therapeutics and resistance mechanisms. We foresee precision medicine becoming an integral component of prostate cancer management to increase response to therapy and prolong survival.

Effect of combination therapy with aminoglutethimide and hydrocortisone on prostate-specific antigen response in metastatic prostate cancer refractory to standard endocrine therapy

A prospective study was performed to investigate the combination of the aromatase inhibitor aminoglutethimide and hydrocortisone in androgen-independent prostate cancer with changes in prostate-specific antigen (PSA) level as main determinant for response. Thirty-five patients were treated with aminoglutethimide 1000 mg daily and hydrocortisone acetate 40 mg daily. PSA measurements were performed every month. If evaluable lesions were present, objective tumor assessment was done by computed tomography scan and X-ray investigations. In 12 patients (37%) the PSA value showed a confirmed response with a decline in serum level of at least 50%. Median time to progression in responding and all patients was 10.5 and 4.5 months, respectively. Median duration of response in responding patients was 9 months. Median survival for these two groups was 23 and 14.5 months, respectively. Of seven patients with measurable disease, two showed a partial response and five a stable disease. Improvement in general condition, pain and feeling of well-being was noted in two-thirds of patients. Therapy was well tolerated with mainly grade I and II adverse events in 20% of patients. We conclude that aminoglutethimide is a valuable second-line therapy for patients with androgen-independent prostate cancer.

Development of prostate cancer treatment: the good news

Prostate cancer is the most commonly diagnosed cancer in American men representing one-third of all new cancer cases each year. This translates into one out of every six American men being diagnosed with prostate cancer over the course of their lifetimes. Over 31,000 of these men die each year from prostate cancer. Before the 1980's, 50% of men were diagnosed with widespread metastatic disease and there were few therapeutic choices for patients. The good news for patients is that, over the last 30 years there have been significant advances in detection and prognostication as well as major improvements in the surgical, radiation, and medical oncological management of prostate cancer. This review describes the evolution of these therapeutic modalities for prostate cancer. This evolution has been driven by the explosion of knowledge concerning cancer in general and in the specific biology of prostate cancer in particular over the last 30 years. This knowledge has been obtained by concentrating human and financial resources in organ specific studies of the prostate. The end result of this effort is that, today, 85% of new prostate cancer cases are diagnosed at local and regional stages and the 5-year relative prostate cancer survival rate has increased by 20% since 1985. In addition, the therapeutic approach to prostate cancer can now be individualized based on the characteristics of the patient's disease. Finally, recent data suggest that the death rate from prostate cancer is decreasing by approximately 4% per year since 1994. Further good news for patients is that new discoveries about the biology of prostate cancer are rapidly being translated into new therapies, a large number of which are currently being tested in clinical trials. Continued allocation of appropriate human and material resources should yield new, more effective therapies for prostate cancer that will further impact patient quality of life and survival in the 21st century.

A history of prostate cancer treatment

The increased incidence of prostate cancer has led to remarkable changes in diagnosis and treatment over the past century. What were the first ways in which prostate cancer was treated, and how did these evolve into the variety of therapeutic strategies from which patients have to choose today?

Endocrine therapy of prostate cancer

Endocrine therapy is effective treatment for patients with metastatic prostate cancer. Most patients will benefit from androgen withdrawal in terms of symptomatic relief and delay in progression of diseases. It does not, however, cure patients with metastatic prostate cancer. This finding emphasizes the need for the development of effective nonendocrine therapies.

Is prednisolone as good as flutamide in hormone refractory metastatic carcinoma of the prostate?

PURPOSE

There are no generally accepted rules for the second line treatment of prostate cancer and few prospective studies have attempted to compare 2 therapeutic strategies with different modes of action.

MATERIALS AND METHODS

We describe a prospective, randomized study of 40 patients comparing the second line response of flutamide to prednisolone in patients with known hormone refractory stage M1 prostate cancer.

RESULTS

The median survival of patients receiving either treatment was 32.9 weeks, with no difference between the 2 groups. In terms of biological response 11 of 20 patients (55%) receiving prednisolone and 10 of 20 (50%) receiving flutamide exhibited prostate specific antigen (PSA) suppression. Average minimum PSA was 54 and 52% of the initial PSA in patients receiving prednisolone and flutamide, respectively. There was no difference between the 2 treatment groups in terms of long-term survival, although 35% of all patients survived beyond 1 year and 3 survived beyond 2 years.

CONCLUSIONS

More patients taking prednisolone described better pain relief, although both medications were well tolerated and there was no difference in terms of performance status or analgesic requirements.

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.

Endocrine therapy of advanced carcinoma of the prostate

Increasing evidence suggests that growth of the prostatic tissue is regulated by a network of hormones and growth factors, in which androgens play the prominent role. Hormonal manipulation remains the core of treatment for locally advanced and metastatic prostate cancer. Achievement of a complete androgen blockade, by surgical or medical means or a combination of both, offers superior results in palliative management of advanced disease. Management of hormonal refractory cancer, however, remains a challenge to clinicians.

Management of relapsing disease in prostate cancer

Almost all patients with prostatic cancer will eventually escape the control of the first-line endocrine therapy and relapse. This escape is attributed to selecting and/or cloning preexisting or de novo appearing hormone-independent or resistant cell lines and occurs in most patients after a median time of 12 to 18 months. Currently, there are no generally accepted rules for second-line management, either endocrine or by other means. It seems reasonable to consider length of survival as the only objective response criterion and not to rely on other response criteria. Available second-line therapeutic modalities in relapsed prostatic cancer are alternative endocrine manipulations, chemotherapy, combined endocrine and cytotoxic therapy, new drugs, radiation therapy, and general antitumoral and supportive care. Second-line therapy in relapsed disease makes sense if life can be prolonged while relieving symptoms and maintaining or improving the quality of survival. The capacity to prolong survival is limited. As a result, second-line therapy should aim more at improving the quality rather than the length of survival while considering the specific expectations and wishes of the patient.

Hormone therapy of prostatic bone metastases

When present at diagnosis or when developing in the course of disease, the presence of bone metastases from prostate cancer is generally considered an indication to begin endocrine therapy, as this is clearly the most effective form of treatment for this problem. Endocrine therapy can stop progression of prostate cancer in 80-85% of cases. Endocrine therapy can relieve pain, prevent pathologic fractures, and prevent neurologic complications from bone metastases from prostate cancer. Rarely, bone scans may become normal after the start of endocrine therapy, but partial improvement or stabilization of bone scans are more commonly seen. While endocrine therapy has been the first line of treatment of metastatic prostate cancer for the past 50 years, the recent development of newer forms of endocrine therapy have increased the options in the past few years. In addition to orchiectomy and estrogens, newer alternatives include inhibitors of androgen synthesis, the class of agents termed "antiandrogens", and luteinizing hormone releasing-hormone (LHRH) analogues either alone or in combination. Orchiectomy causes a prompt fall in serum testosterone and is regarded by many as the "standard" form of endocrine therapy, but there is concern about the psychologic impact of surgery. Estrogens are being used less frequently today because of their real or potential side-effects, including cardiovascular and thromboembolic complications. The development of analogues of LHRH has resulted in another major choice for endocrine therapy, and one which is therapeutically equivalent to orchiectomy or estrogens. Since LHRH analogues may cause an early rise or "flare" in serum testosterone before it drops to castrate level, these agents should not be given alone to patients with severe pain or neurologic problems. The newly available antiandrogen flutamide can block the "flare", and may also improve survival when used with LHRH analogues or orchiectomy, especially when disease is less advanced. Not all studies of "combination therapy" support this conclusion. However, the use of flutamide is increasing significantly in the United States. Both the LHRH analogues and flutamide are fairly safe, but they are very expensive. Their use, in combination, is likely to become a progressively more common form of initial endocrine therapy in the future. The growing application of prostate specific antigen (PSA) as a tumor marker for prostate cancer has made the difficulty in interpreting changes in bone scans a much less critical problem in determining response to endocrine or other forms of therapy for advanced prostate cancer.

Drug therapy of prostatic cancer

While hormonal therapy has been the usual and appropriate treatment of advanced or metastatic prostatic cancer for the past 50 years, the recent development of new therapeutic agents as medical alternatives to orchidectomy has drastically altered the options and perspectives in the treatment of this disease. Estrogens had been the only commonly used drug therapy in the United States. Newer alternatives include androgen synthesis inhibitors, a class of agents termed antiandrogens, and gonadotrophin-releasing hormone (GnRH) [luteinising hormone-releasing hormone (LHRH)] analogues, either alone or in combination. As the result of basic scientific studies and prospective clinical trials which have examined the issue of risk versus benefit, several trends have emerged. In the United States, orchidectomy is waning as the primary treatment option for metastatic prostatic cancer, while estrogen use has declined drastically; GnRH analogues are being prescribed more frequently. Furthermore, combination therapy with GnRH analogues (or orchidectomy, to a lesser extent) and the antiandrogen flutamide is gaining wider acceptance as a primary treatment option. The rationale, advantages, and real or potential disadvantages of these various treatment options are discussed.

Effect of 3-week treatment with [D-Trp6, des-Gly-NH10(2)]LHRH ethylamide, aminoglutethimide, ketoconazole or flutamide alone or in combination on testicular, serum, adrenal and prostatic steroid levels in the dog

Adult male mongrel dogs were treated with the LHRH agonist [D-Trp6, des-Gly-NH10(2)]LHRH ethylamide, aminoglutethimide, ketoconazole or flutamide alone or in combination for 21 days before measurement of steroid levels in the testes, prostate, adrenals and serum. Ketoconazole alone caused a marked stimulation of the intra-testicular concentration of pregnenolone, 17OH-pregnenolone, progesterone and 17OH-progesterone with no or little change of androstenedione, testosterone and dihydrotestosterone. Aminoglutethimide caused a 30-95% inhibition in the concentration of all steroids in the tests while treatment with the LHRH agonist caused a near complete inhibition of all testicular steroids. When administered concomitantly with the LHRH agonist, ketoconazole partly prevented the inhibitory effect of the LHRH agonist on testicular steroid levels. Serum levels of dehydroepiandrosterone, androst-5-ene-3 beta,17 beta-diol, androstenedione and androstane-3 alpha, 17 beta-diol were 75 to 95% inhibited by the LHRH agonist while serum testosterone and dihydrotestosterone concentrations were reduced below detection limits by the same treatment. Moreover, treatment with the LHRH agonist caused a 70-95% reduction in the intraprostatic concentration of testosterone and dihydrotestosterone in all the groups although maximal effect was observed when the LHRH agonist was combined with any of the three other agents. The present data show that while treatment with ketoconazole, aminoglutethimide or Flutamide alone has only partial inhibitory effects on androgen levels, combination with an LHRH agonist provides maximal inhibition. In addition to its direct blockade of the androgen receptor, some of the effect of Flutamide could be related to its blockade of testicular 3 beta-hydroxy-steroid dehydrogenase activity.

Hormonal therapy for advanced prostatic carcinoma

Since the work of Huggins and Hodges, hormonal therapy, i.e., orchiectomy or estrogens, has been the gold standard of treatment for patients with advanced adenocarcinoma of the prostate. Recently, many new drugs have been introduced in the hope of achieving a beneficial response as compared with hormonal therapy, while avoiding some of the adverse effects. Various newer agents are reviewed. It appears that while these agents may be attractive secondary to specific effects, they do not appear to offer any survival advantage over diethylstilbestrol or orchiectomy. Finally, the theory of total androgen blockade is reviewed. Institution of total blockade does not appear to offer a survival advantage over standard androgen blockade.

The rise in testicular androgens during the first days of treatment with an LHRH agonist in the dog can be blocked by aminoglutethimide or ketoconazole

Up to day 6 of treatment of adult dogs, daily subcutaneous administration of 50 micrograms of the LHRH agonist [D-Trp6, des-Gly-NH2-10]LHRH ethylamide causes up to a 3-fold increase in serum testosterone (T) concentration which is followed by a progressive decrease to castration levels (less than or equal to 0.2 ng/ml) at later time intervals (up to 21 days, the last time interval studied). Both aminoglutethimide and ketoconazole, two inhibitors of steroid biosynthesis, cause a 30-40% rise in serum T when administered alone. However, either drug administered in combination with the LHRH agonist completely blocks the transient rise in serum T observed when the LHRH agonist is administered alone. On the other hand, the LHRH agonist prevents the secondary rise in steroid secretion observed when either of the two inhibitors of steroid secretion is used alone. Administration of the pure antiandrogen Flutamide alone or in combination with LHRH-A and an inhibitor of steroid biosynthesis does not influence serum T levels. When the serum levels of pregnenolone, 17-OH-pregnenolone, progesterone, 17-OH-progesterone, dehydroepiandrosterone (DHEA), androstenedione (delta 4-dione), androst-5-ene-3 beta, 17 beta-diol (delta 5-diol), T, dihydrotestosterone (DHT), androstane-3 alpha, 17 beta-diol, androstane-3 beta. 17 beta-diol and 17 beta-estradiol (E2) are analyzed in detail, it can be seen that both aminoglutethimide and ketoconazole not only prevent the rise in serum steroids observed during the first 8 days of treatment with the LHRH agonist but that both compounds enhance the inhibitory effect of the LHRH agonist at later time intervals. A predominant inhibitory effect of ketoconazole is exerted on 17,20-desmolase activity. Aminoglutethimide has little influence on the loss of serum LH bioactivity induced by the LHRH agonist while ketoconazole stimulates the concentration of serum bioactive LH in the absence or presence of simultaneous treatment with the LHRH agonist. The present data clearly demonstrate that aminoglutethimide or ketoconazole can prevent the rise in serum androgens accompanying the first days of treatment with an LHRH agonist in the dog. Moreover, after 3 weeks of treatment, the inhibitory effect of the LHRH agonist on serum androgen levels is enhanced by addition of aminoglutethimide or ketoconazole. Moreover, Flutamide does not interfere with the inhibitory action of the LHRH agonist, aminoglutethimide or ketoconazole, thus suggesting that maximal inhibition of androgen action is likely to be achieved by a combination of these drugs.

Mechanisms of action of aminoglutethimide as endocrine therapy of breast cancer

During the last decade aminoglutethimide has been recognised as a valuable alternative in endocrine therapy for advanced breast cancer. Although some side effects do occur, most often these are initial effects which subside within a few weeks, and cessation of therapy is not usually indicated. Aminoglutethimide was originally introduced as an inhibitor of steroidogenesis in the adrenal cortex. It was soon recognised, however, that inhibition of the non-glandular aromatase, blocking the conversion of androgenic prohormones to oestrogens, was more important, resulting in decreased blood levels of oestrogens. In this review the role of aromatase inhibition as the only important aspect of the mechanism of action of aminoglutethimide is challenged. Evidence has accumulated during the last few years that aminoglutethimide is a most potent inducer of microsomal enzymes. In addition to the pharmacological implications this has (suggesting important interactions), it also points to the possibility that levels of oestrogens are decreased due to accelerated metabolism of these hormones. Based on new experimental data, and also clinical work with alternative aromatase inhibitors, it appears that the antitumour activity of aminoglutethimide may be due to both aromatase inhibition and accelerated metabolism of oestrogens. This seriously challenges the importance of aromatase inhibition alone as a strategy in endocrine therapy of breast cancer, and furthermore suggests that accelerated metabolism of key hormones is an alternative strategy to be explored.

Interactions of aminoglutethimide with analgesics using antinociceptive tests in mice

The action of aminoglutethimide in alleviating bone pain in women with metastatic breast cancer may be due to either an inherent analgesic effect or an interaction with other analgesic drugs. These possibilities have been investigated in mice by conventional antinociceptive tests. In the abdominal constriction test, aminoglutethimide alone had a dose-related antinociceptive activity. A low dose (which had no pharmacological activity) when co-administered with an effective sub-maximal dose of the analgesic, potentiated the effects of the non-steroidal anti-inflammatory drugs (NSAIDs) tested. In the tail immersion test, aminoglutethimide was inactive and did not enhance the antinociceptive activity of the centrally acting analgesics. As cytochrome P450-dependent routes which are inhibited by aminoglutethimide are not involved in the metabolism of the NSAIDs studied, an interaction at the drug metabolism level cannot explain these results. The NSAID-like activity of aminoglutethimide provides some evidence that the drug's mode of action may involve more than the suppression of oestrogen biosynthesis.

Objective responses to ketoconazole therapy in patients with relapsed progressive prostatic cancer

The contribution of adrenal androgens to the maintenance and progression of so-called hormone-unresponsive prostatic carcinoma was studied in 20 patients with advanced relapsed disease. The role played by testicular androgens had been negated by prior orchiectomy or concurrent LHRH analogue therapy. Ketoconazole, an antifungal agent which inhibits adrenal and testicular androgenesis, administered in a dose of 400 mg 8-hourly, resulted in optimal suppression of adrenal androgens. The mean serum androstenedione concentration fell from 8.01 +/- 0.84 nMol/l to 1.55 +/- 0.25 nMol/l, P less than 0.001, and serum testosterone from 1.25 +/- 0.14 nMol/l to 0.36 +/- 0.06 nMol/l, P less than 0.01, after 6 months treatment. There was, however, no significant difference between patients receiving 400 and those receiving 200 mg. Androgen suppression resulted in six objective and ten subjective clinical responses. Ablation of both testicular and adrenal androgens can now be achieved using ketoconazole in combination with orchiectomy or LHRH analogues, but the high incidence of side effects may preclude its use in all patients with prostatic cancer. The results of this study support the concept of "total androgen ablation" as primary therapy in advanced prostatic cancer as a possible means of improving survival in this common malignancy.

Pharmacology of an antiandrogen, anandron, used as an adjuvant therapy in the treatment of prostate cancer

To improve the inhibition of prostate cancer growth obtained by surgical or chemical castration (estrogens or LHRH analogs), blockade of the action of residual androgens of adrenal origin has been proposed. Among antiandrogens acting through the androgen receptor (AR), the nonsteroid anandron (RU 23908) has several advantages over available compounds: megestrol acetate and cyproterone acetate, both steroids, bind substantially to other hormone receptors (progestin, gluco- and mineralocorticoid); and anandron binds only to AR. The nonsteroid flutamide is a prodrug converted to the active metabolite, hydroxyflutamide; anandron is well absorbed on oral administration of an active dose and intact compound disappears slowly from plasma. This may explain why, although in vitro anandron interacts very transiently with AR, in vivo a high level of untransformed anandron is present at the receptor site to induce its antiandrogenic activity. Animal experiments confirm that anandron can counteract the effect of adrenal androgens and inhibit the LHRH analog-induced initial increase in androgen ("flare-up"). Thus, in rats castrated either surgically or by buserelin or DES and supplemented with adrenal androgens (since endogenous adrenal secretion is very low in this species compared to man), anandron decreased prostate weight to control levels. The administration of buserelin to intact rats over 15 days resulted in a significant increase in prostate weight between Days 1 and 5. The addition of anandron to the buserelin inhibited this increase and, furthermore, led to a far greater decrease in prostate weight than that due to buserelin alone at 15 days, indicating a synergy of action.

Investigation of the combination of the agonist D-Trp-6-LH-RH and the antiandrogen flutamide in the treatment of Dunning R-3327H prostate cancer model

The therapy for the treatment of prostate cancer and other sex-steroid-dependent tumors based on agonists of LH-RH has been made more practical and efficacious by the development of a long-acting formulation of microcapsules of D-Trp-6-LH-RH for controlled release. Antiandrogens, which neutralize the effect of endogenous androgens, have been used also in the management of prostate cancer in man. The effects of a simultaneous administration of the antiandrogen flutamide and microcapsules of the agonist D-Trp-6-LH-RH were studied in the Dunning R-3327H rat prostate adenocarcinoma model to determine whether the combination of these two drugs might inhibit tumor growth more effectively than single agents. Microcapsules of D-Trp-6-LH-RH, calculated to release a controlled dose of 25 micrograms/day for a period of 30 days were injected intramuscularly once a month. Flutamide was administered SC at a daily dose of 25 mg/kg. The therapy was started 100 days after the tumor transplantation and continued for 60 days. Tumor weights and volumes were significantly reduced in rats treated with microcapsules or flutamide alone, but the former drug inhibited tumor growth more than the latter. The combined treatment of flutamide and microcapsules significantly decreased tumor weight and volume, but did not exert a synergistic effect on tumor growth, the reduction being smaller for the combination than for the microcapsules alone. There was a significant elevation of serum testosterone, LH, and prolactin in rats treated with flutamide. On the other hand, in rats given microcapsules of D-Trp-6-LH-RH, testosterone fell to castration levels within 7 days and remained at nondetectable values, serum LH and prolactin levels being also suppressed in this group. The combined administration of microcapsules and flutamide also significantly decreased serum testosterone to nondetectable levels by day 7 and suppressed serum LH and prolactin. Our findings raise doubts of whether the daily administration of the combination of LH-RH agonist with an antiandrogen offers an advantage over the use of microcapsules of an agonist like D-Trp-6-LH-RH alone in the treatment of prostatic carcinoma.

Response to aminoglutethimide and cortisone acetate in advanced prostatic cancer

Forty patients with metastatic adenocarcinoma of the prostate were evaluated for response to treatment with aminoglutethimide plus cortisone acetate. All had relapsed from or failed to respond to primary endocrine treatment with orchidectomy or stilboestrol. Nineteen patients (48%) showed subjective response, in most cases relief of bone pain. Side effects limited treatment in only 3 patients. We conclude that aminoglutethimide plus cortisone acetate is a useful addition to the treatment available for this difficult group of patients. The mechanism by which this treatment has a beneficial effect remains unclear.

Clinical effect of aminoglutethimide, medical adrenalectomy, in treatment of 43 patients with advanced prostatic carcinoma

The initial treatment of patients with Stage D prostatic carcinoma with orchiectomy or estrogens is successful in giving objective and subjective improvement for variable periods of time. However, after initial endocrine treatment patients generally relapse, and go on to further progression of their disease. However, a subgroup of approximately 22% of these Stage D prostatic cancer patients respond to either surgical adrenalectomy or hypophysectomy, indicating some degree of continued hormonal responsiveness. Forty-three previously castrated patients with Stage D prostatic carcinoma were treated with 1000 mg of aminoglutethimide and 40 mg of hydrocortisone daily and have been evaluated using the criteria of the National Prostatic Cancer Project. Progression of disease after initial hormonal therapy has varied from 3 to 25 months. One patient has had a complete response, and continues in remission after 290 weeks of therapy. Partial objective responses have been observed in 6 patients, and 10 patients have remained objectively stable for an average of 35 weeks in this latter group.

Preliminary results on the clinical efficacy and safety of androgen inhibition by an LHRH agonist alone or combined with an antiandrogen in the treatment of prostatic carcinoma

We have used the paradoxical antigonadal effects of LHRH agonists as a chemical castration in advanced prostatic cancer. We report early results of a phase II study on the clinical efficacy of the LHRH agonist D-Ser (TBU)6, des-Gly-NH2(10) LHRH administered to patients with stage D prostatic carcinoma. Following dose-range finding studies using either intranasal (IN) (200 micrograms twice/day or 500 micrograms twice/day) or subcutaneous (SC) administration (50 micrograms once/day, we developed a sequential combination of SC (500 micrograms three times/day for seven days) and IN regimen that was administered for 3 to 16 months to a group of 23 patients with stage D prostatic carcinoma. Initiation of therapy was associated with a clinical flare in one patient during the first week of treatment. Mean serum testosterone levels were already decreasing at one week and remained inhibited to levels inferior to 1 ng/ml after the first four weeks of treatment. Overall assessment shows that within the first six months of treatment, 26% patients were improved, 39% were stabilized, and 35% were nonresponders. Fourteen patients were followed during the next six months: 29% continued to respond, 29% escaped, 21% remained stable, and 21% were nonresponders. Histologic studies from castrated patients showed changes in spermatogenesis correlating to the degree and duration of suppression of testicular steroidogenesis without signs of toxicity. Preliminary observations on the combination of the pure antiandrogen RU 23908 with Buserelin (n = 5) or castration (n = 3) suggest that the addition of an antiandrogen does not seem to improve the patients nonresponding to other hormonal suppressive therapy (Buserelin) administered before (n = 3) or concomitantly with the antiandrogen (n = 2). Three relapsing castrate patients responded to the antiandrogen, but the response was temporary in two (eight to nine months of therapy). No side effects other than hot flashes and decreased potency are related to LHRH agonist alone or to the low-dose antiandrogen. Multicenter trials will be necessary to delineate the place of LHRH agonist alone or LHRH agonist combined with an antiandrogen in the treatment of prostatic cancer.

Clinical and biochemical effect of aminoglutethimide in the treatment of advanced prostatic carcinoma

Treatment of male patients with advanced prostatic carcinoma and disease progression after initial endocrine therapy frequently is unsatisfactory. However, approximately 20 per cent of these patients respond to surgical adrenalectomy or hypophysectomy, indicating continued hormonal responsiveness. A total of 25 previously castrated men with stage D carcinoma received 1,000 mg. aminoglutethimide and 40 mg. hydrocortisone daily. The patients were evaluated using the criteria of the National Prostatic Cancer Project. One patient has had a complete response and is in remission after 275 weeks of therapy. A partial response was noted in 4 patients, while the disease was objectively stable in 6. Pre-treatment testosterone and dihydrotestosterone levels were measured in 9 of 25 patients and were significantly reduced statistically during aminoglutethimide therapy (p less than 0.01). Response and drug toxicity are discussed.

Aminoglutethimide therapy for advanced carcinoma of the prostate

The results of aminoglutethimide treatment of 12 patients with advanced progressive metastatic carcinoma of the prostate are reported. As judged by performance status and analgesic requirements, there were subjective improvements in 75% of the group and side effects were minimal. No consistent objective improvements were observed but decrease in plasma androstenedione and testosterone was associated with subjective improvement in most responders. Mean survival of patients following introduction of aminoglutethimide was 6.5 months. Aminoglutethimide "medical adrenalectomy" appears safe and effective in management of advanced carcinoma of the prostate.

Plasma androgen levels after subcapsular orchiectomy or estrogen treatment for prostatic carcinoma

In this study evolution of plasma androgen levels in patients with advanced prostatic carcinoma, treated by either subtotal bilateral orchiectomy or estrogens, was studied in order to determine whether subcapsular orchiectomy results in complete elimination of testicular testosterone secretion and whether in subsequent months there occurs any reactivation of eventually remaining Leydig or increased adrenal androgen secretion. This study, performed on 40 patients having undergone bilateral subcapsular orchiectomy for prostatic carcinoma, shows that this intervention results in testosterone levels in the female range and that during the year following subcapsular orchiectomy there is no evidence for reactivation of Leydig cells or for increased adrenal androgen secretion as evaluated from plasma testosterone, androstenedione, and dehydroepiandrosterone sulphate levels. In patients treated with estrogens we found no evidence for stimulation of adrenal androgen secretion, whereas in neither group of patients with prostatic carcinoma we found evidence for increased androgen levels at the time of recurrence of the carcinoma.

The effects of castration on adrenal testosterone secretion in men with prostatic carcinoma

Selective adrenal vein catheterization was done on intact and castrated men with prostatic carcinoma. Adrenal to peripheral venous testosterone gradients were observed in all patients, indicating adrenal production of this hormone. No compensatory adrenal production of testosterone was noted during a 17-month period after orchiectomy. The data suggest that the human adrenal in castrates produces testosterone, which may explain why adrenal ablation can offer palliation in some patients with prostatic carcinoma.