Alice E. Boucher

Aminoglutethimide as Treatment of Postmenopausal Women with Advanced Breast Carcinoma

Hormone-dependent breast carcinomas respond to deprivation of biologically active estrogens with objectively quantifiable tumor regression. Aminoglutethimide, a known inhibitor of steroid synthesis, is also a potent blocker of the aromatase enzyme and, thus, of estrogen production. We developed an effective regimen to inhibit estrogen production in postmenopausal women using aminoglutethimide and replacement glucocorticoid. One hundred forty-seven women initially received aminoglutethimide and replacement glucocorticoid as treatment of metastatic breast carcinoma. One hundred twenty-nine women are currently evaluable for assessment of clinical and hormonal responses. Thirty-seven percent of unselected women and 49% of estrogen receptor-positive patients experienced objective tumor regression. Responses occurred predominantly in soft tissue (47%) and bone (35%) and lasted 30 +/- 9.1 months for complete and 14 +/- 1.5 months for partial regressions. Plasma and urinary estrogen levels fell equally in responder versus nonresponder groups whereas androgen levels declined less in patients with progressive disease.

Androgen priming and chemotherapy in advanced prostate cancer: evaluation of determinants of clinical outcome.

We conducted a randomized clinical trial in men with stage D2 prostate cancer to test whether androgen priming potentiates the efficacy of cytotoxic chemotherapy. Eighty-five men with progressive prostate cancer refractory to orchiectomy were treated continuously with aminoglutethimide and hydrocortisone to lower adrenal androgen secretion and were administered cyclic intravenous (IV) chemotherapy. The patients were randomized to receive either androgen priming or no additional treatment for three days before and on the day of chemotherapy. Median duration of follow-up was 43 months. Response rate (remission plus disease stabilization) was not significantly different between the stimulation and control arm when the analysis was restricted to evaluable patients (79% v 73%, respectively) or when it was extended to all patients (46% v 61%). Median duration of response was similar for the stimulation and control arm (9 and 10 months, respectively). Median survival was 10 months in the stimulation and 15 months in the control group (P = .0047). The androgen sensitivity of the tumors was supported by the greater toxicity in the stimulation arm associated with androgen administration. Factors found to be independently associated with improved clinical outcome included a high Karnofsky score and hematocrit, long duration of response to the initial castration, and normalization of an elevated serum acid phosphatase on treatment. We conclude that in this group of patients with advanced disease, androgen priming does not potentiate the efficacy of chemotherapy and is actually associated with a worse outcome. Furthermore, our data emphasize the heterogeneity of biologic behavior of prostate cancer.

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.

Somatostatin analogues in the treatment of breast and prostate cancer.

Newly developed somatostatin analogues may be useful agents in the treatment of breast and prostate cancer. Potential mechanisms of antitumor action include suppression of circulating levels of trophic hormones and growth factors as well as direct effects at the tumor level, potentially involving autocrine/paracrine mechanisms. Pilot clinical trials conducted in heavily pretreated women with advanced breast cancer indicate that SMS 201-995 (Sandostatin R) has minimal toxicity and moderately suppresses stimulated growth hormone secretion and basal somatomedin-C level. Somatostatin analogues have also been found to retard the growth of experimental prostate cancer, particularly when used in combination with LHRH analogues. The therapeutic efficacy of these compounds used alone or in combination with other agents in the treatment of breast and prostate cancer remains to be established in larger clinical trials involving less heavily pretreated patients.

Pharmacologic suppression of estrogens with aminoglutethimide as treatment of advanced breast carcinoma

SummaryRecent studies suggest that estrogens are the predominant hormones required for the growth of hormonedependent breast cancers in women. Traditional methods of lowering estrogens as treatment of breast cancer involve surgical removal of the ovaries, adrenals, or pituitary. Newer investigative strategies utilize blockade of estrogen action with antiestrogens or inhibition of estrogen synthesis. As reviewed previously, a regimen for pharmacologic suppression of estrogen production was developed which utilizes the aromatase/steroidogenesis inhibitor aminoglutethimide (AG) and replacement hydrocortisone (HC). The current paper updates recent mechanistic, clinical, and hormonal data regarding AG.The preservation of plasma androstenedione levels concomitant with marked estrone and estradiol suppression suggests that AG lowers estrogen production predominantly by blocking aromatization. The mechanism for sustained androstenedione production in the face of suppressed ketosteroids, glucocorticoids, and mineralocorticoids during AG administration was evaluated in dogs fitted with arteriovenous adrenal cannulae. Inhibition of the adrenal secretion of androstenedione with preservation of peripheral plasma levels of this steroid suggests stimulation ofextra-adrenal 3β-ol-dehydrogenase,Δ5-Δ4-isomerase activity by AG.Clinical studies revealed a 32% objective response rate to AG/HC in unselected patients and a 52% response in women with estrogen receptor positive tumors. Randomized trials indicated similar response rates to AG/HC vs hypophysectomy (AG/HC 47% vs Hypox 21%,p = NS), surgical adrenalectomy (AG/HC 52% vs surgical adrenalectomy 43%,p = NS) and antiestrogen therapy (AG/HC 36% vs tamoxifen 38%,p = NS). Cross-over data revealed that 50% of 94 patients initially responding to tamoxifen later experienced an objective regression to AG/HC. Only 25% of 93 tamoxifen nonresponders benefited later from AG/HC. Trends indicate that bone metastases may respond better to AG/HC (33%) than to tamoxifen (15%).Use of a computer-based data matrix allowed determination of whether patients escape from AG/HC induced estrogen and androgen suppression at the time of disease relapse. No trends towards escape from estrogen inhibition were apparent. However, in the objective responders to AG/HC, the weak androgens dehydroepiandrosterone-sulfate (DHEA-S) and androstenedione appeared to increase prior to disease relapse. DHEA-S but not androstenedione levels remained lower in the objective responders than in nonresponders at all phases of AG/HC therapy. Thus, the estrogens, but not androgens, remain constant during all phases of AG/HC treatment.

Androgen Priming and Response to Chemotherapy in Advanced Prostatic Cancer

A total of 67 patients with progressive stage D2 prostatic cancer refractory to orchiectomy was entered in a controlled clinical trial to test whether androgen priming enhances the efficacy of cytotoxic drugs. All patients were treated continuously with aminoglutethimide and hydrocortisone to lower adrenal androgen secretion and were given cyclic intravenous chemotherapy. In addition, the 34 patients randomized to the stimulation arm received fluoxymesterone for 3 days before and on the day of chemotherapy. There was 33 controls. The median duration of followup was 24 months. A modestly higher response rate (objective remission plus disease stabilization) was observed in the stimulation arm (85 versus 72 per cent, p less than 0.05) when the analysis was restricted to the evaluable patients. However, a larger fraction of unevaluable patients was present in the stimulation group (41 versus 16 per cent), mostly as a result of toxicity from fluoxymesterone, which prompted early discontinuation of treatment. Thus, when data analysis included all patients the response rate actually was slightly higher in the control than in the stimulation arm (60 versus 50 per cent, p not significant). No difference was observed in median duration of response (9 months in both groups) or over-all survival. Our data suggest that at least in those patients with advanced disease androgen priming does not seem to enhance significantly the antitumor effect of the combination of amino-glutethimide and chemotherapy, and is associated with significant toxicity. These largely negative results may be explained by the large number of hormone-resistant cells present in tumors that have become refractory to orchiectomy.

Androgen depletion and repletion as a means of potentiating the effect of cytotoxic chemotherapy in advanced prostate cancer

Seventy-five patients with stage D-2 prostate cancer refractory to orchiectomy have been entered in a controlled trial to test whether androgen priming enhances the efficacy of chemotherapy. All patients are treated with aminoglutethimide and hydrocortisone as a means of achieving medical adrenalectomy and are given cyclic i.v. chemotherapy with cytoxan, adriamycin and 5-fluorouracil. Patients in the stimulation arm (N = 39) receive, in addition, fluoxymesterone (5 mg p.o. b.i.d.) for 3 days before and on the day of chemotherapy. A similar response rate was observed in the stimulation and control arm (83% vs 74% respectively) when the analysis was restricted to evaluable patients. When all patients were included, a significantly higher response rate was observed in the control arm (64% vs 49%, P less than 0.05) as a result of the larger fraction of unevaluable patients in the stimulation arm (41% vs 14%). Median duration of response is 9 months in the stimulation and 10 months in the control arm. Median overall survival in the stimulation and control group is 12 months and 16 months respectively. Significant toxicity consisting of exacerbation of bone pain and, in two patients, development of reversible spinal cord compression was observed following androgen priming. Our results suggest that combined medical adrenalectomy and chemotherapy are highly effective in the treatment of advanced prostate cancer. Thus far, no additional benefit has been observed with androgen priming.