Aminoglutethimide in advanced breast cancer: prospective, randomized comparison of two dose levels. Italian Cooperative Group

In a multicenter randomized clinical trial 106 post-menopausal patients with progressive metastatic breast cancer were allocated to receive 500 mg or 1000 mg Aminoglutethimide (AG) per os daily. Cortisone Acetate (CA) replacement dose was 37.5 mg/day orally in both groups. In 91 fully evaluable patients, no statistically significant difference was observed between the two therapeutic regimens, neither in terms of overall response (28 vs 35%) and by site responses, nor in terms of median time to progression (10.5 vs 14.5 months) and median overall survival (20 vs. 22 months). The tolerability was satisfactory in both regimens. Although no statistically significant differences occurred, in the low dose regimen we observed fewer patients with side-effects (25% vs 6%) and induced grade 3 side-effects (4% vs 9%). Our results confirm that AG daily doses of 500 and 1000 mg associated with corticosteroids have a comparable effect. Because of its slight but clinically noticeable better tolerability, the lower dose is the preferable regimen in the treatment of advanced breast cancer.

Experience with aromatase inhibitors in the treatment of advanced breast cancer

Inhibition of the aromatase enzyme system has become an established means of hormonal treatment for hormone-responsive advanced breast cancer. The widest clinical experience is with aminoglutethimide, which achieves around 30% objective remissions of metastatic disease for up to 1 year. Due to the sometimes serious side-effects of this drug, preclinical and clinical investigations have been undertaken and have yielded a number of steroidal and non-steroidal aromatase inhibitors that have been shown in early or mature clinical trials to give objective disease remissions similar to those with aminoglutethimide but with less toxicity. There is thus good reason to believe that newer aromatase inhibiting drugs will soon be available for routine use in patients with breast cancer. This paper summarizes our experience and reviews data from other groups.

Mitomycin C and aminoglutethimide in the treatment of metastatic prostatic cancer: a phase II study

In a phase II study, 24 patients with metastatic prostatic cancer were treated with mitomycin C 15 mg/m2 i.v. every 6 weeks, combined with aminoglutethimide 250 mg twice a day. A low dose of 37.5 mg cortisone acetate was supplied daily to compensate for adrenal cortical suppression. A partial response was demonstrated in 4 of 24 evaluable patients with bi-dimensionally measurable metastases. Stable disease occurred in 8 patients over a period of more than 6 months. Within the maximum cumulative dose limit of 2 mg/kg body weight mitomycin C, toxicity was observed in 21 cases, including 2 deaths due to treatment toxicity. The poor response rate and high toxicity suggest that the addition of aminoglutethimide does not enhance the effect of mitomycin C in these patients.

Low-dose aminoglutethimide with and without hydrocortisone replacement as a first-line endocrine treatment in advanced breast cancer: a prospective randomized trial of the Italian Oncology Group for Clinical Research

PURPOSE

A randomized study comparing low-dose aminoglutethimide (AG) with and without hydrocortisone (HC) was performed to investigate whether corticosteroid replacement contributes to the therapeutic effects of the drug administered as a front-line endocrine therapy in postmenopausal advanced breast cancer.

PATIENTS AND METHODS

Postmenopausal patients who had not had prior endocrine therapy for advanced disease and with estrogen receptor (ER) or progesterone receptor (PgR) status positive or unknown were eligible. AG was administered at a dose of 250 mg twice a day orally (125 mg twice a day during the first month) with or without HC (20 mg twice a day orally). Seventy-nine and 74 patients were assessable for response on the AG plus HC arm and on the AG arm, respectively. The two treatment groups were well balanced and patients were largely untreated. Approximately 60% had not received any adjuvant treatment, and approximately 75% had not received any medical treatment after relapse.

RESULTS

The overall responses (complete response [CR] plus partial response [PR]) were 44% and 41% for the AG plus HC and the AG arm, respectively, showing no significant difference. Time to progression (median, 8.1 and 6.3 months), duration of response (median, 15.8 and 13.7 months), and duration of survival (median, 34.2 and 36.3 months) were not significantly different between the two treatment arms. Side effects were infrequent and mild in both arms, with no significant differences.

CONCLUSION

We conclude that half of the conventional daily dose of AG has optimal therapeutic activity as a front-line endocrine treatment of postmenopausal advanced breast cancer and that HC does not significantly contribute to the therapeutic effects.

Endocrine, pharmacokinetic and clinical studies of the aromatase inhibitor 3-ethyl-3-(4-pyridyl)piperidine-2,6-dione ('pyridoglutethimide') in postmenopausal breast cancer patients

The aromatase inhibitor, 'pyridoglutethimide' (PyG), has been shown previously to suppress serum oestrogen levels in postmenopausal breast cancer patients and to achieve clinical responses at a dose of 500 mg twice daily (b.d.). This report gives the results of a detailed pharmacokinetic and endocrine study of PyG in ten patients. Four doses were tested at intervals of 2 weeks in the following order: 200 mg b.d., 400 mg b.d., 800 mg b.d., 1200 mg b.d. Concentration-time profiles of serum levels of PyG were curvilinear in all patients probably reflecting a saturation of metabolic enzymes. During repeat-dosing metabolism was enhanced approximately 2-fold. Plasma levels of oestradiol were significantly suppressed by the lowest dose of PyG. Although higher doses appeared to achieve greater suppression this was not statistically significant in this small group of patients. There were no significant effects at any dose on the serum levels of cortisol, aldosterone, luteinising hormone, follicle stimulating hormone, prolactin, sex hormone binding globulin or thyroid stimulating hormone. There was a dose-related increase in 17 alpha-hydroxyprogesterone levels and a dose-related decrease in levels of dehydroepiandrosterone sulphate (DHAS). The androgens DHA, testosterone and androstenedione also were significantly suppressed with at least one of the doses of PyG. Synacthen tests did not support these changes being a result of inhibition of 17,20 lyase. It is possible that they are due to enhanced clearance of DHAS. Two patients experienced no toxicity throughout the study, whilst a total of four patients were withdrawn because of side-effects: one at 400 mg b.d., two at 800 mg b.d., and one at 1200 mg b.d. The most frequent side-effects were nausea and lethargy. One patient showed an objective response to treatment.

[Results of hormone therapy with aminoglutethimide (Rodazol) in postmenopausal metastatic breast cancer]

44 postmenopausal women with progressive soft tissue, osseous and/or pleuropulmonal metastases of breast cancer were treated with aminoglutethimide (Rodazol) and hydrocortisone. 40 of the 41 patients, evaluated for treatment results, were pretreated hormonally and 17 were additionally pretreated chemotherapeutically. Objective remissions were achieved in 8 of the total of 41 patients (20%) and in 7 of the women (35%), who had previously responded to tamoxifen. Pain reduction was achieved in 4 of 17 cases (23%) with skeletal pain as the main symptom. The response rate was lower than expected. Primary hormonal therapy with Rodazol cannot be recommended in the osseous type of metastatic spread.

Primary systemic therapy for operable breast cancer

Eighty-eight patients presenting with operable breast cancer of 4 cm or greater in diameter (T2, T3, N0, N1, M0) have received primary systemic therapy. Response was assessed following 12 weeks of systemic therapy by linear regression analysis of changes in tumour volume. Definitive locoregional surgery (mastectomy n = 82, wide local excision n = 6) was performed on completion of systemic therapy (3-6 months). Response was observed in 24 (39%) of the 61 patients who received endocrine therapy; all 24 had tumours with an oestrogen receptor (ER) concentration of greater than or equal to 20 fmol mb-1 cytosol protein. Cytotoxic therapy was reserved for patients with tumours of ER concentration less than 20 fmol mg-1 cytosol protein (n = 27) or when endocrine therapy had failed (n = 20). Response was observed in 34 patients (72%). The overall survival rate at 3 years was 86%, with 81% remaining free from local relapse. We propose that the treatment policy outlined in this paper should now be tested against orthodox management by controlled randomised trial.

Response to steroid suppression in major depression resistant to antidepressant therapy

Because of the similarities in the psychiatric symptoms of Cushing's syndrome and those of major depression, and because the former generally remits when the hyperadrenalism is alleviated, an open clinical trial of the effect of steroid suppression in major depression was undertaken. Ten patients satisfying the DSM-III-R criteria for major depression, and classified as treatment-resistant, were included. Eight patients completed the study, which consisted of discontinuation of other psychotropic drugs and 2 months' treatment with one or more steroid suppressive agent (aminoglutethimide, ketoconazole and/or metyrapone). Six were classified as responders, and two as partial responders. In six, the improvement has been sustained for longer than 5 months after withdrawing the drugs. Side effects were mild to moderate. These results provide some evidence that steroids are involved in the maintenance of major depression, and that their suppression may lead to a readjustment of the hypothalamic-pituitary-adrenal axis with remission of the depression.

Recent progress in development of aromatase inhibitors

In postmenopausal women with breast cancer, aromatase, which is the enzyme converting androstenedione to estrone and testosterone to estradiol, is the rate-limiting step in estrogen biosynthesis. The currently available aromatase inhibitor, aminoglutethimide, effectively blocks estrogen production and products tumor regression in patients previously treated with tamoxifen. This drug, however, produces frequent side effects and blocks steroidogenic steps other than the aromatase enzyme. Thus, newer aromatase inhibitors with greater potency and specificity are under intense study. More than 20 such compounds have recently been developed. In several clinical trials, 4-hydroxyandrostenedione, given parenterally, has been highly active and specific for aromatase inhibition in patients with breast cancer. In two large recent studies, one-third of heavily pretreated woman experienced objective tumor regression with this therapy. CGS 16949A, a newer agent, is also in Phase III clinical trials. This compound is an imidazole derivative with nearly 1000-fold greater potency than aminoglutethimide. An initial Phase I study compared the potency of 0.6-16 mg daily in 12 postmenopausal women and found maximal suppression of urinary and plasma estrogens with 2 mg daily. The degree of inhibition was similar to that induced by aminoglutethimide or by surgical adrenalectomy. No CNS, hematologic or biochemical toxicity was observed. A larger Phase II study in 54 patients confirmed this high degree of potency of CGS since a plateau effect was observed at the 1.8, 2 and 4 mg daily doses. The endocrine effects were not absolutely specific as a blunting of ACTH-stimulated but not basal aldosterone levels were observed. This and other emerging aromatase inhibitors offer promise as pharmacologic methods to inhibit estrogen production specifically and without side effects.

Thrombocytopenia following Treatment with Low Doses of Aminoglutethimide

The authors report a case of severe thrombocytopenia during treatment with low doses of aminoglutethimide in a woman with advanced breast cancer. Hematologic toxicity secondary to aminoglutethimide did not seem to be dose-related, and an immunologic mechanism may be postulated. Although the incidence of the side effect is probably low, monitoring of blood counts during the first months of therapy is necessary.

Second line hormonal therapy with aminoglutethimide in metastatic breast cancer

One hundred and twenty patients with metastatic breast cancer, whose disease progressed on hormonal therapy with tamoxifen, were treated with aminoglutethimide. The overall response rate was 34% and the median duration of response 9.5 months. Response to aminoglutethimide was achieved in all metastatic sites except lung and brain. Even 25% of patients who had failed to respond to prior tamoxifen did respond objectively to aminoglutethimide. The actuarial survival for all patients at 30 months was 22%. Although initial toxicity was high (70%), side effects of aminoglutethimide were transient, and treatment had to be discontinued in only four patients. The results of this trial confirm that aminoglutethimide is an effective treatment in metastatic breast cancer.

Megestrol acetate versus aminoglutethimide for metastatic breast cancer

In this prospective, randomized study the clinical response and toxicity of megestrol acetate (MA) and aminoglutethimide (AG) as second-line treatment in patients with metastatic breast cancer was compared. 176 patients were included, and 150 received treatment greater than 8 weeks and are evaluable for treatment response. The two groups did not differ with regard to prognostic factors. Response rate for the AG and MA groups were 34% and 31% respectively, with duration of response of 13.1 and 13.0 months. Stable disease was obtained in 33% and 35% respectively. No difference was observed in survival. Side effects occurred more frequently in the AG group (42%) than in the MA group (18%).

A study of aminoglutethemide and hydrocortisone in patients with advanced and refractory prostate carcinoma

We have studied aminoglutethemide (AG) combined with hydrocortisone in 28 patients with advanced and refractory prostate carcinoma. All the patients had failed at least one endocrine therapy. Six patients received only one prior hormonal treatment. Five patients were off study within 3 weeks due to early death and toxicity, 14 had progressive disease, and 9 had stable disease. No objective partial remission was observed, but the nine stable patients had therapeutic benefit, with improvement in bone pain and performance status for a median duration of 153 days. Three patients withdrew because of postural hypotension, dizziness, weakness, and lethargy. The median survival of the entire group was 186 days (range 41-606 days). Our results suggest that aminoglutethemide and hydrocortisone can be an alternative treatment for patients with advanced and refractory prostate carcinoma.

Phase II study of low dose aminoglutethimide 250 mg/day plus hydrocortisone in advanced postmenopausal breast cancer

Low dose aminoglutethimide 125 mg twice daily plus hydrocortisone 20 mg twice daily was shown to produce oestrogen and androgen suppression in postmenopausal women. A phase II study was carried out in 101 patients with advanced postmenopausal breast cancer. Objective response rates were 4% CR and 21% PR. Fourteen per cent had disease stabilization for more than 6 months (SD). Soft tissue sites showed the best response. Responses occurred in previous tamoxifen failures (28%) including SD. Toxicity was less than reported for higher dose regimens or low dose aminoglutethimide without hydrocortisone, particularly nausea and drowsiness. Survival from first relapse and start of therapy was not significantly different between PR and SD. This dosage regimen appears of comparable efficacy to previously reported higher dosage regimens with reduced toxicity compared to low dose regimens without hydrocortisone.

Aminoglutethimide-induced hyperkalaemia

Aminoglutethimide, a drug which inhibits adrenal hormone synthesis, may alleviate pain in metastatic breast carcinoma. A case is reported in which severe hyperkalaemia supervened two years after commencing treatment with aminoglutethimide; a constant dose was used in conjunction with cortisone supplements. This indicates the need for constant biochemical monitoring, or better still, prophylactic administration of fluorohydrocortisone as mineralocortical replacement. This is the first case of aminoglutethimide-induced hyperkalaemia reported, illustrating the rarity of the complication. Adrenal failure due to glucocorticoid deficiency was also present and required an increased dosage of cortisone. Maintenance of glucocorticoid and mineralcorticoid need regular review throughout therapy, to counteract intercurrent stress.

Aminoglutethimide in patients with metastatic breast cancer

Aminoglutethimide (AG) was administered as palliative therapy in 112 patients with metastatic breast cancer. In 36 patients, the dose level was 1000 mg/day; 76 patients received a dose level of 500 mg/day. Patients with brain or liver metastasis were excluded, as were patients with tumors determined to be negative for estrogen receptors. Objective regression was observed in 35 (31%) patients, with the duration of response ranging from 4 to 36 + months (mean, 12 months; median, 10 months). Response was observed in 11 of 31 (35%) patients with soft tissue metastasis; 16/59 (27%) patients with osseous metastasis; and 8 of 22 (36%) having visceral metastasis. In 93 patients with positive estrogen receptor (ER), 33 responded (35%), whereas in 19 patients with unknown ER status, two responded (11%). Response to previous treatment with tamoxifen (TAM) had occurred in 31 patients; of these, response to AG was noted in 11 (35%). Of 24 patients failing to respond to prior treatment with tamoxifen, four (17%) responded to subsequent therapy with AG. Thirteen patients had previously received combination chemotherapy, and response to AG was noted in two (15%). The side effects observed in this study included skin rash in ten patients, fever in eight, somnolence in three, weakness and dizziness in one, headache in one, insomnia in one, dyspnea in one, and ataxia in one. Treatment had to be discontinued in eight patients, due to the severity of the side effects. As expected, patients receiving AG at the lower dose level of 500 mg/day experienced fewer and less severe side effects than those treated with the higher dose. The response rate in the 1000 mg/day group was 10/36 (28%) and in the 500 mg/day group, it was 25/76 (33%). The lower dosage was better tolerated without apparent compromise in therapeutic efficacy.

[Clinical observation on hypercortisolism treated with amino-glutethimide]

We reported the clinical results in 13 cases of hypercortisolism treated with amino-glutethimide (AG), which was developed by Tiantsin Research Institute of Medical Industry. Of the thirteen cases nine were confirmed by surgery and histology, and the others were diagnosed clinically. Clinical improvements have been achieved in ten of the thirteen cases over a therapeutic course of 8 to 12 wk with a daily dosage of 1.0 to 2.0 g of AG. Plasma and urinary corticosteroids, as well as plasma testosterone levels were significantly decreased after one-month treatment followed, however, by somewhat return and fluctuation. The high levels of blood glucose and serum insulin were declined after therapy consistent with the decrement of corticoids. Serum potassium levels in hypokalemic patients returned to normal after one month of therapy. Radial bone mineral contents in patients with low bone density returned or closed to normal after three-month treatment. The main side effects of AG are anorexia, nausea, drowsy, tierdness, skin rashes, etc, which are mild and transient. Adrenal hypofunction was seen in one case after treatment.

[Transient bone marrow inhibition caused by aminoglutethimide]

A 53-year-old woman with reversible bone marrow insufficiency caused by aminoglutethimide (AGT) treatment of metastatic breast carcinoma is described. The clinical picture included moderate thrombocytopenia and severe granulocytopenia complicated by Gram-positive septicaemia and skin infections, and by oral candidiasis. Withdrawal of AGT and antibiotic therapy resulted in clinical and haematological recovery, but the patient died suddenly, probably from a cardiac cause. Autopsy revealed widespread bone metastases, but no bone marrow infiltration of breast carcinoma. The haematological hazards caused by application of AGT are discussed.

Medical adrenalectomy for advanced prostatic cancer: clinical and hormonal effects

We examined the effect of medical adrenalectomy on the clinical and hormonal responses in 50 men with disseminated prostatic carcinoma. Patients refractory to initial hormonal therapy were treated with aminoglutethimide and hydrocortisone (AG-HC) and evaluated by the criteria of the National Prostatic Cancer Project. Eight patients showed a partial response (PR), and 17 remained stable while receiving these medications. Survival times for these two groups averaged 87.8 and 38 weeks, respectively. In contrast, 17 men were unresponsive to this therapy, exhibiting progressive disease with a mean survival time of 18 weeks. Eight patients could not tolerate the drug regimen or were lost to follow-up. Serum and urinary hormone profiles determined serially during AG-HC therapy revealed that all measured serum androgens and estrogens were significantly lowered by AG-HC treatment; however, specific hormones, including free testosterone, dihydrotestosterone, estrone, and estradiol were suppressed to a greater degree in responders (R) as compared with nonresponders (NR). Urinary excretion of 17-ketosteroids did not change during AG-HC therapy, but specific androgen metabolites, including testosterone glucuronide and androstanediol glucuronide, were suppressed by 50% during AG-HC therapy. We showed modest clinical benefit of AG-HC therapy in advanced prostatic cancer. That greater hormonal suppression was associated with greater responsiveness to this therapy raises the hope that further manipulations directed against suppression of extratesticular androgens may be a useful approach as second-line treatment of advanced prostatic cancer.

A phase II evaluation of combination chemotherapy plus aminoglutethimide in women with metastatic or recurrent breast carcinoma. An Eastern Cooperative Oncology Group Pilot Study

The Eastern Cooperative Oncology Group (ECOG) conducted a pilot study of combination chemotherapy with cyclophosphamide, doxorubicin, and 5-fluorouracil plus aminoglutethimide (250 mg three times daily with hydrocortisone supplementation of 40 mg daily) as primary therapy for estrogen receptor-positive or unknown advanced breast carcinoma to assess whether these agents can be safely combined and to provide a preliminary estimate of response rate. A total of 47 patients, 45 with metastatic breast cancer and two with stage IV disease who were rendered clinically disease free following surgical resection of chest wall recurrence, were treated. Leukopenia and mucositis were the most frequent toxicities requiring dose reduction, but only five patients (10.6%; 95% confidence interval, 1.8-18.4%) experienced life-threatening leukopenia (less than 1000/mm3) at some point during their therapy. Neurologic side effects attributed to aminoglutethimide, predominantly lethargy, were reported in less than one-third of patients, and rarely required dose reduction. One elderly patient developed clinical hypothyroidism during the first 3 months on therapy and experienced a cardiac arrest at home while receiving supplemental thyroid hormones. The overall complete plus partial response rate in 45 patients was 55.5% (95% confidence interval, 41-70%). Among 16 patients with measurable disease, the complete plus partial response rate was 75% (95% confidence interval, 54-96%). The complete plus partial response rate in 29 patients with nonmeasurable but evaluable disease was 45% (95% confidence interval, 27-63%) and an additional 14% had improvement in bone pain. Eight patients electively discontinued chemotherapy after 7-24 months of therapy, but continued aminoglutethimide. The median time to disease progression is 462 days (15.4 months); 25% of patients died by 552 days (18.4 months), and the median duration of survival is predicted to be 889 days (29.6 months). We conclude that aminoglutethimide can be combined with this doxorubicin-based regimen with acceptable toxicity and an overall response rate which is similar to that observed on prior ECOG trials with cyclophosphamide, doxorubicin, and 5-fluorouracil.

Randomized trial of tamoxifen versus aminoglutethimide and versus combined tamoxifen and aminoglutethimide in advanced postmenopausal breast cancer

In a randomized trial, 105 postmenopausal women with advanced carcinoma of the breast received tamoxifen or aminoglutethimide or combined tamoxifen and aminoglutethimide. No differences were found in the rate of responses and duration of responses between the treatment groups. Toxicity was significantly greater (p less than 0.01) in patients who received aminoglutethimide.