Medical and surgical adrenalectomy in patients with advanced breast carcinoma

History of Estrogen: Its Purification, Structure, Synthesis, Biologic Actions, and Clinical Implications

This mini-review summarizes key points from the Clark Sawin Memorial Lecture on the History of Estrogen delivered at Endo 2018 and focuses on the rationales and motivation leading to various discoveries and their clinical applications. During the classical period of antiquity, incisive clinical observations uncovered important findings; however, extensive anatomical dissections to solidify proof were generally lacking. Initiation of the experimental approach followed later, influenced by Claude Bernard's treatise "An Introduction to the Study of Experimental Medicine." With this approach, investigators began to explore the function of the ovaries and their "internal secretions" and, after intensive investigations for several years, purified various estrogens. Clinical therapies for hot flashes, osteoporosis, and dysmenorrhea were quickly developed and, later, methods of hormonal contraception. Sophisticated biochemical methods revealed the mechanisms of estrogen synthesis through the enzyme aromatase and, after discovery of the estrogen receptors, their specific biologic actions. Molecular techniques facilitated understanding of the specific transcriptional and translational events requiring estrogen. This body of knowledge led to methods to prevent and treat hormone-dependent neoplasms as well as a variety of other estrogen-related conditions. More recently, the role of estrogen in men was uncovered by prismatic examples of estrogen deficiency in male patients and by knockout of the estrogen receptor and aromatase in animals. As studies became more extensive, the effects of estrogen on nearly every organ were described. We conclude that the history of estrogen illustrates the role of intellectual reasoning, motivation, and serendipity in advancing knowledge about this important sex steroid.

Celebrating 75 years of oestradiol

Oestrogens exert important effects on the reproductive as well as many other organ systems in both men and women. The history of the discovery of oestrogens, the mechanisms of their synthesis, and their therapeutic applications are very important components of the fabric of endocrinology. These aspects provide the rationale for highlighting several key components of this story. Two investigators, Edward Doisy and Alfred Butenandt, purified and crystalized oestrone nearly simultaneously in 1929, and Doisy later discovered oestriol and oestradiol. Butenandt won the Nobel Prize for this work and Doisy's had to await his purification of vitamin K. Early investigators quickly recognized that oestrogens must be synthesized from androgens and later investigators called this process aromatization. The aromatase enzyme was then characterized, its mechanism determined, and its structure identified after successful crystallization. With the development of knock-out methodology, the precise effects of oestrogen in males and females were defined and clinical syndromes of deficiency and excess described. Their discovery ultimately led to the development of oral contraceptives, treatment of menopausal symptoms, therapies for breast cancer, and induction of fertility, among others. The history of the use of oestrogens for postmenopausal women to relieve symptoms has been characterized by cyclic periods of enthusiasm and concern. The individuals involved in these studies, the innovative thinking required, and the detailed understanding made possible by evolving biologic and molecular techniques provide many lessons for current endocrinologists.

Additive endocrine therapy for advanced breast cancer - back to the future

While novel endocrine treatment options have been implemented in the advanced - as well as adjuvant setting, recent results suggest a place for "old-fashioned" additive treatment with estrogens in advanced breast cancer. This paper reviews the biological rationale for endocrine therapy in general and additive treatment with estrogens in particular. The finding that patients becoming resistant to treatment with aromatase inhibitors may subsequently respond to estrogen therapy adds important information to our understanding of therapy resistance in general. Moreover, the return of a therapeutic option abandoned more than 20 years ago, now to be used in a different sequential setting, suggests a critical examination whether there may be other conventional treatment options still earning a place as treatment in advanced disease as well. While ablative therapies including surgical oophorectomy, hypophysectomy and adrenalectomy are not candidate treatment options due to morbidity, there are additive treatment options apart from estrogen therapy that may be considered. Androgens administered at therapeutic doses are not feasible for toxicity reasons; yet, the potential of adding androgens in small doses as adjuvant to aromatase inhibitors should be further explored. Whether patients become resistant to other treatment options may still benefit from megestrol acetate, remains to be explored.

History of aromatase: saga of an important biological mediator and therapeutic target

Aromatase is the enzyme that catalyzes the conversion of androgens to estrogens. Initial studies of its enzymatic activity and function took place in an environment focused on estrogen as a component of the birth control pill. At an early stage, investigators recognized that inhibition of this enzyme could have major practical applications for treatment of hormone-dependent breast cancer, alterations of ovarian and endometrial function, and treatment of benign disorders such as gynecomastia. Two general approaches ultimately led to the development of potent and selective aromatase inhibitors. One targeted the enzyme using analogs of natural steroidal substrates to work out the relationships between structure and function. The other approach initially sought to block adrenal function as a treatment for breast cancer but led to the serendipitous finding that a nonsteroidal P450 steroidogenesis inhibitor, aminoglutethimide, served as a potent but nonselective aromatase inhibitor. Proof of the therapeutic concept of aromatase inhibition involved a variety of studies with aminoglutethimide and the selective steroidal inhibitor, formestane. The requirement for even more potent and selective inhibitors led to intensive molecular studies to identify the structure of aromatase, to development of high-sensitivity estrogen assays, and to "mega" clinical trials of the third-generation aromatase inhibitors, letrozole, anastrozole, and exemestane, which are now in clinical use in breast cancer. During these studies, unexpected findings led investigators to appreciate the important role of estrogens in males as well as in females and in multiple organs, particularly the bone and brain. These studies identified the important regulatory properties of aromatase acting in an autocrine, paracrine, intracrine, neurocrine, and juxtacrine fashion and the organ-specific enhancers and promoters controlling its transcription. The saga of these studies of aromatase and the ultimate utilization of inhibitors as highly effective treatments of breast cancer and for use in reproductive disorders serves as the basis for this first Endocrine Reviews history manuscript.

Review: aromatase inhibitors for ovulation induction

CONTEXT

For the last 40 yr, the first line of treatment for anovulation in infertile women has been clomiphene citrate (CC). CC is a safe, effective oral agent but is known to have relatively common antiestrogenic endometrial and cervical mucous side effects that could prevent pregnancy in the face of successful ovulation. In addition, there is a significant risk of multiple pregnancy with CC, compared with natural cycles. Because of these problems, we proposed the concept of aromatase inhibition as a new method of ovulation induction that could avoid many of the adverse effects of CC. The objective of this review was to describe the different physiological mechanisms of action for CC and aromatase inhibitors (AIs) and compare studies of efficacy for both agents for ovulation induction.

EVIDENCE ACQUISITION

We conducted a systematic review of all the published studies, both controlled and noncontrolled, comparing CC and AI treatment, either alone or in combination with gonadotropins, for ovulation induction or augmentation, identified through the Entrez-PubMed search engine.

EVIDENCE SYNTHESIS

Because of the recent acceptance of the concept of using AIs for ovulation induction, few controlled studies were identified, and the rest of the studies were pilot or preliminary comparisons. Based on these studies, it appears that AIs are as effective as CC in inducing ovulation, are devoid of any antiestrogenic side effects, result in lower serum estrogen concentrations, and are associated with good pregnancy rates with a lower incidence of multiple pregnancy than CC. When combined with gonadotropins for assisted reproductive technologies, AIs reduce the dose of FSH required for optimal follicle recruitment and improve the response to FSH in poor responders.

CONCLUSIONS

Preliminary evidence suggests that AIs may replace CC in the future because of similar efficacy with a reduced side effect profile. Although worldwide experience with AIs for ovulation induction is increasing, at present, definitive studies in the form of randomized controlled trials comparing CC with AIs are lacking.

The role of aromatase inhibitors in ameliorating deleterious effects of ovarian stimulation on outcome of infertility treatment

Clinical utilization of ovulation stimulation to facilitate the ability of a couple to conceive has not only provided a valuable therapeutic approach, but has also yielded extensive information on the physiology of ovarian follicular recruitment, endometrial receptivity and early embryo competency. One of the consequences of the use of fertility enhancing agents for ovarian stimulation has been the creation of a hyperestrogenic state, which may influence each of these parameters. Use of aromatase inhibitors reduces hyperestrogenism inevitably attained during ovarian stimulation. In addition, the adjunct use of aromatase inhibitors during ovarian stimulation reduces amount of gonadotropins required for optimum stimulation. The unique approach of reducing hyperestrogenism, as well as lowering amount of gonadotropins without affecting the number of mature ovarian follicles is an exciting strategy that could result in improvement in the treatment outcome by ameliorating the deleterious effects of the ovarian stimulation on follicular development, endometrial receptivity, as well as oocyte and embryo quality.

Biological rationale for endocrine therapy in breast cancer

Oestrogens are heavily implicated in the risk to, and progression of, breast cancer. Therapeutic strategies targeted at the oestrogenic stimulus to the breast and hormone-sensitive breast cancers are extremely attractive measures both to prevent the disease and to treat established tumours. The present review outlines the biological rationale for such endocrine therapy and traces the evolution whereby irreversible surgical procedures have been replaced by potent and specific drugs. In particular, the development of the latest generation of agents which inhibit oestrogen biosynthesis (aromatase inhibitors) is considered by defining the central role of the aromatase enzyme, its regulation and contribution to circulating and tumour endogenous oestrogens. The nature of response and resistance which may be elicited following the use of endocrine therapy is also described as this may determine the optimal use of aromatase inhibitors and, more generally, anti-hormone therapy in the management of women at high risk to, or with, breast cancer.

Aromatase inhibitors for the treatment of infertility

Ovarian stimulation during infertility treatment is used either alone or in conjunction with intrauterine insemination and assisted reproductive technologies. At the present time, the two main medications used for ovarian stimulation include an oral antioestrogen, clomiphene citrate and injectable gonadotrophins. In spite of the high ovulation rate, the use of clomiphene citrate is associated with adverse side effects and low pregnancy rates. In clomiphene citrate failures, gonadotrophin injections are generally the next treatment option but, especially in polycystic ovarian syndrome, are associated with increased risk of severe ovarian hyperstimulation syndrome and high multiple pregnancies. Therefore, an effective oral treatment that could be used without risk of ovarian hyperstimulation syndrome and with minimal monitoring is preferred. It was hypothesised that aromatase inhibitors can be administered early in the follicular phase to induce ovulation by releasing the hypothalamus and/or pituitary from oestrogen negative feedback. The success of aromatase inhibitors in induction and augmentation of ovulation has been reported. In addition, increased intraovarian androgen levels may synergise with central effects of decreased oestrogen to enhance ovarian response to gonadotrophin stimulation. This increased sensitivity to follicle-stimulating hormone may be especially useful in poor responders. The potential future applications for aromatase inhibitors in infertility management are also discussed.

Tamoxifen resistant and refractory breast cancer: the value of aromatase inhibitors

Tamoxifen has dominated endocrine treatment of breast cancer for over two decades. It is useful in metastatic breast cancer, adjuvant therapy, preoperative treatment, ductal carcinoma-in-situ and chemoprevention. However, breast cancer may be refractory to tamoxifen or develop resistance to it with ongoing treatment. This resistance involves several mechanisms including receptor mutation causing 'estrogen hypersensitivity' and an increasing agonist effect of tamoxifen. Megestrol (megestrol acetate), in North America, and aminoglutethimide, in Europe, have been the traditional second line therapies after tamoxifen in advanced breast cancer. Aromatase (estrogen synthetase) inhibitors are a logical alternative to tamoxifen to antagonise the effects of estrogen on breast cancer. The third-generation non-steroidal aromatase inhibitors anastrozole, letrozole and vorozole, and the steroidal inhibitor exemestane, have been studied after tamoxifen versus either megestrol or aminoglutethimide. They showed enhanced efficacy and significantly superior toxicity profiles. Compliance with the inhibitors was also significantly better than with the traditional treatments. Aromatase inhibitors have most recently been shown to be superior to tamoxifen as initial therapy and are being extensively tested in the adjuvant setting after, or instead of, tamoxifen. Pilot studies of chemoprevention are also being undertaken. The aromatase inhibitors are an important new addition to the armamentarium of breast cancer therapy.

Aromatase inhibition for ovarian stimulation: future avenues for infertility management

Ovarian stimulation is applied during infertility management either alone or in conjunction with intrauterine insemination and assisted reproductive technologies. At the present time, the two main medications used for ovarian stimulation include an oral antiestrogen, clomiphene citrate, and injectable gonadotropins. In spite of the high ovulation rate with the use of clomiphene citrate, the pregnancy rate is much lower. In clomiphene citrate failures, gonadotropin injections have generally been used as the next treatment option. Treatment with gonadotropins is difficult to control and characteristically associated with increased risk of severe ovarian hyperstimulation syndrome and high multiple pregnancies. Therefore, an effective oral treatment that could be used without risk of hyperstimulation and with minimal monitoring is the preferred therapy. We hypothesize that aromatase inhibitors can be administered early in the follicular phase to induce ovulation by releasing the hypothalamus or pituitary from estrogen negative feedback. Based on this hypothesis, we have reported the success of aromatase inhibitors in induction and augmentation of ovulation in addition to improving ovarian response to gonadotropin stimulation. Moreover, there are other potential applications for aromatase inhibitors in infertility management, including improving implantation in assisted reproduction and in-vitro maturation.

Antiaromatase agents: evolving role in adjuvant therapy

The goal of adjuvant hormonal therapy is to prevent breast cancer recurrence. Standard therapy with tamoxifen has shown great value in the adjuvant setting; however, its tolerability profile can render it unsuitable for some patients. The aromatase inactivator, exemestane, and the 2 aromatase inhibitors, letrozole and anastrozole, have been shown to be equivalent or superior to tamoxifen with respect to multiple endpoints in patients with metastatic breast cancer. With tolerability profiles that are similar to, and in many cases, more acceptable than that of tamoxifen, and efficacy potentially superior to tamoxifen, studies using the antiaromatase agents as adjuvant therapy are currently ongoing. These trials will answer some important questions, such as the order in which adjuvant hormonal therapies are selected to maximize efficacy, whether the antiaromatase agents show improved tolerability, and whether combination therapy is more effective than monotherapy.

Clinical efficacy and endocrine activity of vorozole in postmenopausal breast cancer patients. Results of a multicentric phase II study

BACKGROUND

Aminoglutethimide was the first aromatase inhibitor to be used successfully in breast cancer patients. However, this drug also inhibits mineralcorticoid and glucocorticoid synthesis, making co-medication with corticosteroids necessary, and it is often poorly tolerated. The primary objective of this trial was to evaluate the clinical efficacy and tolerability of vorozole, a new non-steroidal oral aromatase inhibitor, in postmenopausal breast cancer patients. The secondary objective was to evaluate the pharmacodynamic activity of the drug.

SUBJECTS AND METHODS

Thirty-four postmenopausal patients previously treated with tamoxifen in the adjuvant setting and/ or for advanced disease were treated with vorozole, 2.5 mg once daily. Patients were monitored with respect to treatment efficacy and safety. Hormonal evaluations were performed at baseline and during the course of treatment in order to evaluate the pharmacodynamic efficacy and safety of vorozole.

RESULTS

According to UICC criteria, there were seven responders, one complete and six partial, for an overall response rate of 21% (95% confidence interval (CI) 9%-38%). The median duration of response was 9.6 months (95% CI 4.6-0), the median time to progression for the entire group was 4.7 months (95% CI 2.9-6.6) and the median survival time was 29.7 months (95% CI 19.1-0). Tolerability was excellent to good in 97% of the patients. Oestradiol and oestrone levels were suppressed to the limit of detection of the assays used. No effect was observed on the other endocrine parameters.

CONCLUSIONS

Our results suggest that vorozole is an effective and safe drug for the treatment of advanced postmenopausal breast cancer following tamoxifen failure.

Mechanisms of action of endocrine treatment in breast cancer

Endocrine treatment plays an important role in the therapy of breast cancer. While the basic mechanisms are understood, additional mechanisms may be of importance to their action and they may also contribute to the mechanism(s) of acquired resistance. Currently, several novel drugs are entering into clinical trials. Observations of the absence or presence of cross resistance to novel 'pure' steroidal antiestrogens and the non-steroidal tamoxifen may add important information to our understanding of the mechanisms of action of both classes of drugs. Similarly, exploration of different aromatase inhibitors in sequence or concert, as well as the combining of different endocrine treatment options may be warranted. Additionally, alterations in different biochemical parameters such as growth factors should not only be carefully explored in relation to treatment options but should also be followed during the course of treatment to asess alterations over time and in relation to the development of drug resistance.

Adrenal effects of low-dose aminoglutethimide when used alone in postmenopausal women with advanced breast cancer

Aminoglutethimide (Ag) is a potent aromatase-enzyme inhibitor used in the treatment of patients with breast cancer. In the past, it has been administered in doses of 1,000 mg/d (usually with 40 mg hydrocortisone). At these dose levels, the drug also affects multiple cytochrome P-450 enzymes, including enzymes for adrenal steroid biosynthesis. Recently, lower-dose regimens (500 mg/d) of Ag have been found to be just as effective for breast cancer therapy, but less toxic than the higher conventional dose. There is limited information on the adrenal effects at the lower dosages, and it is not known whether these effects are clinically significant. We measured basal and synthetic corticotropin (Cortrosyn)-stimulated levels of adrenal steroids in postmenopausal breast cancer patients before and during treatment with low-dose Ag (500 mg/d) administered without a glucocorticoid preparation. Basal levels of progesterone, 17-OH progesterone, and 11-deoxycortisol were higher after 2 months' treatment (P < .01). After ACTH injection, peak levels of progesterone and 17-OH progesterone were higher (P < .01), but in contrast, peak levels of 18-OH corticosterone were lower during treatment (P < .02). Basal and peak levels of cortisol, aldosterone, and all other adrenal steroids were unchanged during treatment. We conclude that low-dose Ag treatment leads to partial inhibition of the 21-hydroxylase, 11-hydroxylase, and 18-hydroxylase adrenal enzymes. Since cortisol and aldosterone secretion remained normal with minimal shunting to or accumulation of adrenal androgen compounds, we believe that the mild inhibition was compensated for by further endogenous ACTH stimulation.

First generation aromatase inhibitors--aminoglutethimide and testololactone

Aminoglutethimide and testololactone may be considered the first generation aromatase inhibitors for the endocrine treatment of breast carcinoma. Initially, both of these agents were designed and used clinically based on different concepts of their mechanisms of action. Only later were they both demonstrated to inhibit aromatase. Curiously, testololactone was earlier and more widely used than aminoglutethimide in treating advanced breast carcinoma. The discovery of the peripheral aromatase inhibition as the proper mechanism of action was delayed for both the agents but was relatively more timely for aminoglutethimide. Paradoxically, the clinical use of testololactone has become already obsolete since its true mechanism of action was discovered. Aminoglutethimide is still the most widely used aromatase inhibitor in treating advanced breast carcinoma. Due to the initial misinterpretation of its mechanism of action, aminoglutethimide was used for a long time at a relative high daily dose, always combined with hydrocortisone. Subsequent phase II and then randomized phase III studies demonstrated an equivalent efficacy using half (500 mg) of the previous conventional daily dose (1000 mg), with hydrocortisone. Very recently, a randomized clinical trial demonstrated that administering this lower dose without hydrocortisone did not significantly decrease the clinical efficacy. By decreasing the dose of aminoglutethimide, the incidence of side effects has been reduced. So, the last paradoxical aspect of the aminoglutethimide story is that this agent seemed initially very toxic but finally, with the new schedules, shows a very low toxicity profile, especially after the first few weeks of treatment.

Alterations in the production rate and the metabolism of oestrone and oestrone sulphate in breast cancer patients treated with aminoglutethimide

Plasma level, plasma clearance, production rate and interconversions of oestrone and oestrone sulphate were measured in six breast cancer patients receiving aminoglutethimide therapy. Three additional patients had the production rate of oestrone sulphate investigated. Plasma oestrone and oestrone sulphate levels were reduced by a mean of 46% (P less than 0.05) and 71% (P less than 0.005) respectively. These alterations were due to a combined action of aminoglutethimide inhibiting oestrogen production but also increasing oestrogen metabolism. While oestrone and oestrone sulphate production rate was reduced by a mean of 31% (P less than 0.05) and 41% (P less than 0.005) respectively, the plasma clearance rate of oestrone was found to be increased by a mean of 30% (P less than 0.05), and the plasma clearance rate of oestrone sulphate was increased by a mean of 112% during aminoglutethimide treatment. The fraction of oestrone sulphate converted into plasma oestrone was reduced by 52% (P less than 0.05), the transfer of circulating oestrone into sulphate was non-significantly reduced by a mean of 16%. The findings in this investigation show that aminoglutethimide treatment influences oestrogen disposition by mechanisms unrelated to aromatase inhibition. The possibility that such effects might be partly responsible for the mechanism of action of aminoglutethimide in advanced breast cancer should be considered.

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.

On the role of additive hormone monotherapy with tamoxifen, medroxyprogesterone acetate and aminoglutethimide, in advanced breast cancer

We analyzed the results of clinical studies on the therapeutic efficacy of hormone monotherapy with tamoxifen, medroxyprogesterone acetate, and aminoglutethimide in metastatic breast cancer, which were published between 1971 and 1986 and involved altogether 7000 patients. The overall response rates in patients treated with these hormonal single agents at various dose levels ranged from 31%-42%. When only estrogen receptor-positive patients were considered, the response rates lay between 41% and 54% in groups which were treated with the antiestrogenic agents tamoxifen or aminoglutethimide. The duration of remission was 12 months for tamoxifen- and aminoglutethimide-treated women, whereas medroxyprogesterone acetate effected remissions lasting from 6-16 months. The overall mean survival from start of therapy in tamoxifen- and aminoglutethimide-treated groups was 20 months, whereas information concerning this therapeutic parameter was available only in a minority of medroxyprogesterone acetate-treated groups. With respect to the response by site of metastatic lesions, all three agents caused a significantly higher degree of remissions in the soft tissue as compared to visceral disease.

Aromatase in breast cancer and the role of aminoglutethimide and other aromatase inhibitors

Approximately one third of human breast carcinomas are hormone dependent and regress upon reduction of circulating estrogen levels. Traditional treatment strategies utilized surgical ablative methods to lower estrogen concentrations as treatment of breast cancer. Currently, investigative emphasis is focused upon development of highly specific antiestrogens and inhibitors of estrogen production. The enzyme, aromatase, as the terminal step in estrogen biosynthesis, is a logical target for blockade with potent and specific inhibitors. The earliest available aromatase antagonist, aminoglutethimide, suppresses estrogen production to the same extent as surgical ablation and is an effective treatment for breast cancer. Aminoglutethimide, however, blocks other cytochrome P-450-mediated steroid hydroxylations, requires concomitant glucocorticoid administration, and is associated with initial side effects. Several more specific inhibitors by destroying aromatase irreversibly as well as by competitive inhibition. One of these, 4-hydroxy-androstenedione, has been intensively studied in animals and is undergoing clinical trial. New data regarding these inhibitors further emphasize the key role of aromatase in estrogen production and the practical utility of blocking this enzyme.

Aminoglutethimide treatment in advanced breast cancer: an efficient therapy as a late endocrine alternative in a sequential therapeutic approach

During the last 2 years we have treated 24 patients (23 females and 1 male) with aminoglutethimide plus glucocorticoid for advanced breast cancer. More than half of the patients had received more than 3 systemic treatments before start of aminoglutethimide (AG), and at least half of the patients had been given more than 2 different endocrine regimens. There were 8 previous responders to endocrine therapy and in 10 patients steroid receptor status predicted response to therapy. Nine of 22 patients (two had to stop after less than 1 month due to acute toxicity) had an objective response; there were 2 complete responders. Most side effects were not serious, subsiding within a few weeks. In one patient agranulocytosis was observed. AG with glucocorticoid replacement seems to be an effective treatment as a late endocrine alternative in a sequence of different endocrine regimens.

Medical adrenalectomy in patients with advanced breast cancer

Medical adrenalectomy, consisting of aminoglutethimide plus either dexamethasone or hydrocortisone, was administered to 53 women with advanced breast cancer. Sixteen (30%) patients had an objective response, five patients had stabilization of disease, 26 patients demonstrated progression of disease, two patients did not adhere to protocol, and four patients had severe toxicity necessitating discontinuation of the drugs. Medical adrenalectomy accurately predicted response to subsequent surgical adrenalectomy in 23 patients. Estrogen receptor (ER) data accurately predicted response (eight of nine (89%) ER-positive patients responded) or failure (only two of 14 (14%) ER-negative patients responded) to medical adrenalectomy. Thirty (of 51 women adhering to protocol) had no toxicity. Therefore, it appears that medical adrenalectomy is safe, usually well tolerated, and can accurately predict response to surgical adrenalectomy. Its use should be limited to ER-positive patients, and it may totally supplant surgical adrenalectomy in the management of advanced breast cancer.

Tamoxifen and aminoglutethimide in the management of patients with advanced endometrial carcinoma not responsive to medroxyprogesterone

Eleven patients with advanced endometrial carcinoma not responsive to medroxyprogesterone were entered into a trial of therapy with tamoxifen, aminoglutethimide or both in combination. Two patients had a complete response, 1 to aminoglutethimide and 1 to tamoxifen. One patient who initially had a partial response to tamoxifen but then relapsed, had a partial response to aminoglutethimide. Two patients had stable disease for 8 and 6 months on aminoglutethimide, and 1 patient who initially showed no response to tamoxifen has had stable disease for 14 months since addition of aminoglutethimide to therapy. The relative lack of toxicity of these drugs make their use attractive in the management of such patients.

Suppression of estrogens with aminoglutethimide and hydrocortisone (medical adrenalectomy) as treatment of advanced breast carcinoma: a review

Fifty to sixty percent of postmenopausal women with estrogen receptor positive metastatic breast cancer respond objectively to surgical ablation of the pituitary or adrenal glands. Several investigators have recently developed medical alternatives to surgical ablative therapy for these patients. This review describes one of these strategies, the inhibition of estrogen synthesis with the enzyme inhibitor aminoglutethimide (AG). Aminoglutethimide blocks several cytochrome P-450-mediated steroid hydroxylation steps including those required for cholesterol to pregnenolone conversion and for the aromatization of androgens to estrogens. In women with metastatic carcinoma, a regimen including 1,000 mg of AG and 40 mg of hydrocortisone as replacement glucocorticoid was administered daily. 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 revealed that AG-HC produced objective regression as frequently as surgical adrenalectomy (Ag-HC + 53% vs. surgical adrenalectomy (43%, p = NS), and as surgical hypophysectomy (AG-HC 47% vs. hypox 21%, p + NS). Comparison of AG-HC administration with antiestrogen treatment suggested an equal rate of response to either therapy. Preliminary data document responses to AG in antiestrogen-resistant patients. Current studies do not allow precise recommendations regarding the sequence of use of antiestrogens and AG-HC.

The treatment of metastatic breast cancer with aminoglutethimide

Thirty-eight patients with advanced breast cancer, resistant to prior endocrine therapy and in most cases prior chemotherapy, were treated with aminoglutethimide, 250 mg qds. Seven of 30 evaluable patients (23%) responded. Six have subsequently relapsed with a mean duration of response of 17 weeks, while one continues to respond after 50 weeks of therapy. Six additional patients (20%) had stable disease during aminoglutethimide therapy (mean duration of 16 weeks). Three of the seven responders had shown a partial response, two had stable disease and two had progressive disease on prior endocrine therapy (including tamoxifen); six of the seven patients responding to aminoglutethimide had received prior combination chemotherapy, to which all had responded. Aminoglutethimide was generally well tolerated, although three patients withdrew from treatment within the first two weeks because of intolerable drowsiness. Aminoglutethimide offers a useful alternative to surgical adrenalectomy for women with advanced breast cancer responsive to previous endocrine and cytotoxic chemotherapy.

Medical adrenalectomy with aminoglutethimide in the management of advanced breast cancer

Sixty-five patients with actively progressing advanced breast cancer were treated with aminoglutethimide, a drug which inhibits adrenal steroid synthesis and decreases peripheral conversion of androgens to oestrogens. Of the 38 patients who have so far been classified, 13 (34%) have experienced objective regression of their disease, while in a further six patients (16%) the disease has become static. The median duration of the objective remission was in excess of 14 months, while in the group with static disease, the median duration of the static condition was longer than eight months. Side effects were either nonexistent or mild in the majority of cases, and the drug was well tolerated. Aminoglutethimide is an important new modality in the treatment of advanced breast cancer.

Preservation of androgen secretion during estrogen suppression with aminoglutethimide in the treatment of metastatic breast carcinoma

We evaluated the comparative effects of aminoglutethimide (AG) on androgen and estrogen levels estrone ([E1], estradiol [E2], plasma dehydroepiandrosterone-sulfate [DHEA-S], testosterone [T], dihydrotestosterone [DHT], delta 4-androstenedione [delta 4-A]), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin in postmenopausal patients with breast cancer randomly allocated to either AG treatment or bilateral surgical adrenalectomy as a control group. In response to either treatment, the plasma levels of E1 fell 62-75% (P less than 0.001) and urine E1 85.7-88.7% (P less than 0.001) in all study days over a 12-wk period. Similarly, the concentrations of E2 in plasma and urine fell 40-72% without statistically significant differences between the two treatment modalities. The relatively weak androgen, DHEA-S, was reduced by 92% (877.3 +/- 184.6 to 71.8 +/- 14.5 ng/ml) at 12 wk in women treated with AG, but suppressed nearly 99% (1,151 +/- 262 to 5.8 +/- 3.3 ng/ml) in adrenalectomized women. At all time points after treatment, the DHEA-S levels were significantly higher in patients receiving AG. Plasma concentrations of the potent androgens, T and DHT, were also relatively preserved during AG treatment. T levels were never significantly reduced by AG, and DHT concentrations were decreased only at the 4th wk to a maximum of 20%. delta 4-A levels fell 56% in response to this drug only on the 12th wk of therapy (basal, 0.79 +/- 0.09 ng/ml; 12 wk, 0.35 +/- 0.07 ng/ml). In marked contrast, all androgens fell significantly at each time period in response to surgical adrenalectomy, with an 81% maximum suppression of T, 73% of DHT, and 97% of delta 4-A. In response to estrogen suppression, plasma levels of FSH, LH, and prolactin did not change significantly throughout the treatment period in either therapy group. To examine possible contributions of the postmenopausal ovary to hormone levels during therapy, data from surgically castrate and spontaneously menopausal women were evaluated separately. No significant differences between the two groups were observed for E1, E2, T, DHT, DHEA-S, delta 4-A, LH, FSH, and prolactin. We conclude that equivalent and highly significant estrogen suppression occurs with either AG or surgical adrenalectomy although androgen secretion is preserved during AG treatment but not after surgical adrenalectomy. The combined effects of estrogen deprivation associated with androgen preservation might be significant in the therapeutic action of AG in hormone-responsive neoplasms.

Palliative therapy for metastatic breast cancer

Breast cancer may recur in the form of localized or generalized metastatic disease. Although localized metastasis is almost always evidence of more widespread occult disease, local therapy is often of prolonged palliative value. Generalized metastasis calls for systemic therapy, and hormone methods in many cases can provide long-term control before chemotherapy must be resorted to. The therapeutic approach depends on whether the patient is premenopausal or postmenopausal. Generally, ablative is more effective than additive hormone therapy. Whether a given patient will respond can be predicted to a degree by hormone receptor tests.

Influence of estrogen receptor status on response of metastatic breast cancer to aminoglutethimide therapy

Aminoglutethimide (AG) is an effective chemical ablative form of therapy for metastatic breast cancer in postmenopausal women. Estrogen receptor (ER) status in breast cancer is useful in predicting the response to the hormonal treatments. Of 134 postmenopausal metastatic breast cancer patients treated with AG, ER analysis was done in 63 patients, 52 of whom are now evaluable. ER biopsy was performed prior to Ag therapy in 61 patients, but the results were not known to the investigators. ER value greater than or equal to 10 fmol/mg cytosol protein was considered ER positive (ER+), 4-9.9 fmol/mg borderline, and less than 4 fmol/mg ER negative (ER-). In 38 ER+ patients, objective response rate was 50% (three complete response, 16 partial response) and eight stabilization. Median duration of objective response was 15 months. Forty-three percent of the patients with borderline estrogen receptor level responded objectively (three partial response) with the median duration of response eleven months. Fourteen percent of ER- patients responded objectively (one complete response). Hence the estrogen receptor level predicts response in ER+ and ER borderline patients treated with AG.

Aminoglutethimide in the management of metastatic breast cancer

Aminoglutethimide (AG) with Dexamethasone has been utilized in 26 patients with metastatic breast cancer who had prior response to hormonal manipulation and/or positive estrogen receptor. Objective tumor response (CR + PR) has been achieved in 13 of 26 patients. Responses were seen in soft tissue, bone, and pleura. Six of 26 patients had stable disease and seven of 26 patients had progressive disease. The median duration of response is 12.8 months. The median survival for the responders has not been reached. Non-responding patients had a median survival of five months. Side effects were minimal, including mild lethargy, rash, fever, and weight gain. This regimen is well tolerated and can be used effectively in metastatic hormone-receptor-positive breast cancer.

Effect of a vegetarian diet and dexamethasone on plasma prolactin, testosterone and dehydroepiandrosterone in men and women

This study reports the effect of a vegetarian diet and dexamethasone administration on the hormone status of healthy Caucasian men and premenopausal women. A lower nocturnal release of prolactin and testosterone occurred in men fed a vegetarian diet, while in women, dexamethasone administration decreased the nocturnal release of prolactin and caused a greater decrease of plasma dehydroepiandrosterone (DHEA). These results show that diet modification can induce hormonal changes, If similar changes occur in patients with breast and/or prostatic cancer, diet modification may be of benefit in these patients with tumors known to be hormonally dependent.

Hormone relationships in breast cancer: the role of receptor-binding proteins

The introduction of receptor protein studies as markers for hormone dependence of breast carcinomas has had a profound effect on the management of advanced disease. All breast carcinomas, regardless of stage, should have receptor binding protein studies for estrogen and progesterone by the sucrose gradient method or by the dextran-coated charcoal method as a good alternative. A simpler test is needed. In cases of primary advanced disease or in recurrent disease, receptor binding protein studies effectively identify the subgroup of hormone-dependent tumors that should be managed by surgical hormone ablation or endocrine manipulation. These tests are even more effective in identifying patients that should not receive hormone therapy and respond better to chemotherapy. In primary, potentially surgically curable disease, receptor studies may serve as a therapeutic guide to adjuvant hormone or chemotherapy. In all breast cancers, ER and PgR receptor studies should be performed and the information should be stored for possible future use. If possible, tisssue should be stored in a freezer in anticipation of future tests and for confirmation of hormone dependence in the event of recurrence.

Aminoglutethimide in treatment of metastatic breast carcinoma

42 patients with metastatic breast carcinoma were treated with aminoglutethimide, which inhibits adrenal steroid hormone synthesis. Treatment was stopped in 2 patients before response could be assessed; of the other 40, 15 (37.5%) had an objective response, 1 (2.5%) showed a response in bone but not in soft tissue, and 4 (10%) had complete or very great relief of metastatic bone pain but no radiological evidence of improvement. 19 (53%) of 36 patients with bone metastases responded to treatment (15 had X-ray evidence and 4 had pain relief), as did 5 (45%) of 11 patients with soft tissue metastases, 2 (25%) of 8 with malignant marrow infiltration, 1 (14%) of 7 with lung metastases, and none of 13 with liver metastases. Response was commonest in patients who had previously responded to other forms of endocrine therapy. Side-effects, usually mild and transient, occurred in a few patients; the most important were an initial period of somnolence in 9 patients and a rash in 5.

Breast carcinoma associated with Klinefelter syndrome: a case report

Klinefelter syndrome increases the risk of developing breast cancer to approximately 1/5 that of women and 20 times that of normal men. A case report and the patient's response to hormone manipulation for metastatic disease is described.

High dose medroxyprogesterone-acetate treatment in advanced mammary carcinoma. A phase II investigation

In a phase II investigation of high dose medroxyprogesterone treatment of advanced and previously with other methods heavily treated patient with mammary carcinoma, 7 of 25 patients had a partial remission with a median duration of 5 + months. In a further 7 patients the disease became stationary. As measured by Karnofsky's scale, a median improvement of 20 points was obtained in these 14 patients. In 4 of 15 patients who had not responded to Tamoxifen treatment, a partial remission occurred following MAP therapy. The patients tolerated MAP well.