Zoladex: endocrine and therapeutic effects in post-menopausal breast cancer

Dual-targeting aromatase binding domain of heme and androstenedione by Pt(IV) prodrug: a new treatment for postmenopausal breast cancer

The combination of endocrine therapy and chemotherapy is an attractive approach for treating breast cancers. Aromatase inhibitors (AIs) are the first-line drugs for postmenopausal ER-positive breast cancer and adjuvant therapy...

Tolerability of hormone therapies for breast cancer: how informative are documented symptom profiles in medical notes for 'well-tolerated' treatments?

Hormonal therapies for cancer are often viewed as a gentler option than many other cancer treatments, but is low toxicity an accurate perception of patients' experiences? Side effects tend to be described as minimal or well tolerated, yet published symptoms from hormonal therapy vary considerably in their descriptions and frequencies. Previous research has highlighted under-reporting of side effects by clinical staff so as part of a wider study examining tamoxifen and goserelin treatment as adjuvant therapy for breast cancer, treatment-related symptoms documented in medical notes were compared with those that patients reported during a research interview. There was a significant difference in the frequency of many side effects reported by the two methods in this study. Sixty four out of 72 (89%) women who had received adjuvant tamoxifen or goserelin had side effects recorded in their medical notes, compared with 74/75 (99%) reporting side effects at interview. We compared the published frequencies of commonly reported symptoms with those found ourselves. The discrepancies between patient-reported and clinician-recorded (usually from clinical trial data) symptom profiles were similar to those found in our study. Without accurate comprehensive side effect profiles for hormone therapies, prospective patients cannot make informed judgements on proposed treatments.

Ovarian surface epithelium: biology, endocrinology, and pathology

The epithelial ovarian carcinomas, which make up more than 85% of human ovarian cancer, arise in the ovarian surface epithelium (OSE). The etiology and early events in the progression of these carcinomas are among the least understood of all major human malignancies because there are no appropriate animal models, and because methods to culture OSE have become available only recently. The objective of this article is to review the cellular and molecular mechanisms that underlie the control of normal and neoplastic OSE cell growth, differentiation, and expression of indicators of neoplastic progression. We begin with a brief discussion of the development of OSE, from embryonic to the adult. The pathological and genetic changes of OSE during neoplastic progression are next summarized. The histological characteristics of OSE cells in culture are also described. Finally, the potential involvement of hormones, growth factors, and cytokines is discussed in terms of their contribution to our understanding of the physiology of normal OSE and ovarian cancer development.

Autocrine role of gonadotropin-releasing hormone and its receptor in ovarian cancer cell growth

We have recently proposed an autocrine role of gonadotropin-releasing hormone (GnRH) and its receptor (GnRH-R) in human ovarian surface epithelium. In the present study, we examine the presence and role of a GnRH/GnRH-R loop in epithelial ovarian cancer cells, OVCAR-3. A dose-dependent biphasic response in GnRH and GnRH-R mRNA levels were observed after treating with GnRH agonist [GnRHa, (D-Ala6)-GnRH], for 24 h. High concentrations of GnRHa (10(-9) M and 10(-7)) decreased the GnRH and GnRH-R mRNA levels, whereas a low concentration (10(-11) M) resulted in an upregulation of GnRH and GnRH-R genes expression. Cotretment with the competitive antagonist, antide, prevented the biphasic effect induced by GnRHa, confirming the specificity of the response. In addition, GnRHa treatment resulted in a time- and dose-dependent inhibition on OVCAR-3 cells growth. A significant inhibition of proliferation was detected as early as the d 2 of treatment. Treatment with 10(-7) M GnRHa induced DNA fragmentation in OVCAR-3 cells, suggesting that the GnRHa-induced antiproliferation in OVCAR-3 cells was mediated by apoptosis. Again, this effect was prevented by cotreatment of antide. Taken together, our findings strongly support the notion that GnRH acts as an autocrine/paracrine regulator of ovarian cancer cell proliferation.

Endocrine therapy in metastatic breast cancer

Endocrine therapy represents a mainstay of effective, minimally toxic, palliative treatment for metastatic breast cancer. Research focusing on the mechanism of action of endocrine agents will provide new insights leading to new hormonal approaches in breast cancer treatment. Development of new agents, especially the 'pure' antiestrogens, is of great interest. Combining endocrine therapy with biologic agents, especially antiproliferative compounds, may lead to more effective treatment in the adjuvant as well as the advanced setting. Tables 4 and 5 summarize response rates to the different groups of endocrine agents used in metastatic breast cancer and doses of commonly used agents, respectively. At present, tamoxifen is the drug of choice as first-line endocrine therapy for metastatic breast cancer with no or minimal symptoms in premenopausal or postmenopausal women. Second-line therapy usually consists of megace. Aromatase inhibitors may be used as second- or third-line therapy in postmenopausal women. In premenopausal women, LHRH analogues are a reasonable choice. The other hormonal agents may be beneficial as salvage therapy. More effective endocrine approaches are under development.

LHRH agonist treatment of breast cancer and gynecological malignancies: a review

Since 1982 LHRH agonists have been used as a treatment modality in patients with disseminated breast cancer and gynecologic malignancies, based on the assumption of steroid dependence of these cancers. They have been successfully used in the treatment of premenopausal women with breast cancer; response rates reported are 31-63%. Less optimistic results have been reported in postmenopausal breast cancer patients as well as in the treatment of women suffering from ovarian cancer. Response rates for treatment of postmenopausal breast- and ovarian cancer patients appear to be up to 22% and 29%, respectively. Studies using LHRH agonists to treat endometrial and cervical intra-epithelial neoplasia are still rare and, until now, no data about the efficacy of LHRH agonists in treating these malignancies have been reported. This paper reviews clinically important studies of LHRH agonists, including a rationale for the use of LHRH agonists in breast cancer and gynecological cancer treatment. In view of the changed endocrine state in postmenopausal women on the one hand and alterations in endocrine metabolism in breast cancer tissue on the other hand, it is concluded that it might be more effective to use a combination of LHRH agonists and other endocrine modalities to treat disseminated breast cancer and gynecological malignancies.

Assesssment of the effect of pretreatment with neoadjuvant therapy on primary breast cancer

Patients with invasive cancer of the breast (T1-4, N0-2, M0) were assigned to pretreatment based on oestrogen receptor (ER) status; patients with ER-negative tumours received chemotherapy [mitozantrone, methotrexate and mitomycin C (MMM)] for 3 months, patients with ER-positive tumours underwent endocrine therapy [luteinising hormone releasing hormone (LHRH) agonist goserelin (leuprolide-premenopausal) or 4-hydroxyandrostenedione (formestane-post-menopausal)] for 3 months. Of the first 100 patients assessed at 3 months, 47 with ER-positive tumours had a 40.4% response (premenopausal 53.8%; post-menopausal 35%) and 53 with ER-negative tumours had a 60% response (premenopausal 57%; post-menopausal 63%). Patients with early breast cancer (T1/T2) had a complete clinical resolution in 41% (16/39) of cases after MMM and in 20% (7/35) of cases following endocrine therapy compared with 14% (2/14) advanced tumours (T3/T4) following MMM and (0/12) following endocrine therapy. However, in those patients achieving a complete clinical response, subsequent appropriate surgery showed that 16 of 19 patients (84%) had evidence of residual viable tumour on histological examination.

Expression of the gene for the receptor of gonadotropin-releasing hormone in the rat mammary gland

Recent findings have demonstrated that the GnRH gene is expressed in the mammary gland of pregnant and lactating rats but not of virgin rats. Indeed, significant concentrations of biologically active GnRH have been found in milk of human, cow, sheep and rat. We have, therefore, looked for expression of the GnRH receptor in the rat mammary gland. By reverse transcription (RT)-PCR amplification, we have demonstrated the presence of GnRH receptor mRNA in mammary gland samples derived from virgin, pregnant and lactating rats. The GnRH receptor transcript cloned from the mammary gland was sequenced and found to have an identical coding region to the one cloned from the pituitary gland. In addition, we have found that the mammary gland, as the pituitary gland, contains at least two transcripts having the same coding region but different 5' non-coding regions. Binding studies, however, could demonstrate only low-affinity binding sites. These results, therefore, suggest that the regulation of the GnRH receptor occurs posttranscriptionally rather than at the level of transcription.

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.

Effect of Decapeptyl (a GnRH analogue) and of transforming growth factor-alpha (TGF-alpha), in the presence of heparin, on the sulfatase activity of human breast cancer cells

The effects of the polypeptide Decapeptyl (a gonadotropin-releasing hormone (GnRH) agonist analogue) and of transforming growth factor-alpha (TGF-alpha), on estrone sulfate-sulfatase activities in the homogenates of various breast cancer cell lines were studied in the presence of heparin. In hormone-dependent MCF-7 breast cancer cells, Decapeptyl can inhibit sulfatase activity, and this effect is significantly augmented in the presence of heparin. In the other hormone-dependent T-47D breast cancer cell line, the decrease of sulfatase activity was only significant when Decapeptyl was associated with heparin. No significant effect on sulfatase activity elicited by heparin, Decapeptyl or a mixture of both was found in the hormone-independent MDA-MB-231 breast cancer cells. TGF-alpha stimulates sulfatase activity in the MDA-MB-231 cells but has no effect in the MCF-7 cells; in contrast, TGF-alpha combined with heparin provokes a decrease of the sulfatase activity in both cell lines. It is concluded that the sulfatase activity in some types of breast cancer cell can be inhibited by heparin combined with the polypeptides Decapeptyl or TGF-alpha.

Pituitary down-regulation with a single depot-dose of a GnRH agonist (triptorelin) in postmenopausal women

Gonadotropin levels were determined in 17 postmenopausal women before and after administering a single depot-dose of the GnRH agonist triptorelin. E2 levels of all samples were in the normal (low) postmenopausal range and no differences were found when the patients were grouped according to chronological age, or time after menopause. Pre-GnRH agonist levels of LH and FSH were in the normal (high) postmenopausal range. Two weeks after medication, LH and FSH had decreased to premenopausal levels (P < 0.0001). Eight weeks after medication, LH levels were still low whereas FSH levels had risen significantly again (P < 0.0001). Both LH and FSH levels, however, were still significantly below the serum concentrations before the administration of triptorelin (P < 0.0001). The pre-GnRH agonist level of FSH was significantly higher in women > 67 years old (P < 0.05), as compared to women < 67 years. Two weeks after medication both LH and FSH levels were significantly higher in women more than 15 years after menopause (P < 0.05), as compared to those < 15 years. The same was found for FSH in women > 67 years old. No further significant differences were noted. This study demonstrates a significant decrease of LH and FSH serum levels in postmenopausal women within two weeks after administration of a single depot-dose of the GnRH agonist triptorelin. After eight weeks, in contrast to premenopausal women, both LH and FSH, although rising, were still significantly suppressed.

Gonadotropin-releasing hormone receptor in gynecologic tumors. Frequent expression in adenocarcinoma histologic types

BACKGROUND

Gonadotropin-releasing hormone (Gn-RH) analogs have been used in the therapy of the endocrine-dependent cancers. The authors attempted to determine the frequency with which Gn-RH receptor (Gn-RHR) is present in gynecological cancers.

METHODS

Experiments were performed on gynecologic tumors that had been surgically removed and their cloned cell lines. Gn-RHR was characterized by [3H]Gn-RH binding to plasma membrane preparations. Gn-RHR messenger ribonucleic acid was determined by reverse transcription-polymerase chain reaction using oligonucleotide primers synthesized according to the published human Gn-RHR sequence.

RESULTS

High affinity binding sites with nanomolar range of Kd and Gn-RHR mRNA were detected in a high proportion (over 90%) of the specimens from endometrium (6 of 6) and endometrial carcinomas (16 of 17), myometrium (6 of 6) and myomas (4 of 5), epithelial carcinoma (21 of 23), and stromal tumors (3 of 3) of the ovary. There was no substantial Gn-RHR in cervical carcinomas or germ cell-derived tumors of the ovary. Cloned cell lines gave identical results to those obtained in their respective mother tumors.

CONCLUSIONS

We detected Gn-RHR in a wide range of the carcinomas and tissues originating from the endometrium and ovary, but not in the uterine cervix or germ cell-derived tumors. The expression of Gn-RH receptor raises the possibility that Gn-RH may play a direct regulatory role in the growth of these carcinomas, and provides a possible point of attack for therapeutic approaches using Gn-RH analogs in these malignancies.

Endocrine changes with the aromatase inhibitor fadrozole hydrochloride in breast cancer

Fadrozole hydrochloride is a potent aromatase inhibitor with proven clinical effectiveness. However, its optimal dose and its effects on serum aldosterone levels/electrolyte balance have been disputed. To resolve these issues, a double-blind randomised endocrine study of three doses of fadrozole hydrochloride [0.5 mg twice daily (bd); 1.0 mg bd; 2.0 mg bd] was conducted in 80 (68 evaluable) postmenopausal patients with advanced breast cancer over a period of 3 months. There were substantial falls in the serum levels of oestradiol, oestrone and oestrone sulphate. For oestrone only, there was a significant effect of dose (on-treatment means: 0.5 mg, 38.0 pmol/l; 1.0 mg, 25.0 pmol/l; 2.0 mg, 23.9 pmol/l). All oestrogens showed a similar pattern in relation to time, with the 3-month mean being higher than those at 1 and 2 months, and this was significant for oestradiol (P = 0.012). There was an indication that complete suppression of oestradiol and oestrone was not maintained throughout the 12-h dosing period, but the data and its interpretation are complicated by a minor diurnal rhythm in these parameters. There were significant increases in 17-hydroxyprogesterone and androstenedione which may be due to a block of 11 beta-hydroxylase. There was a statistically non-significant fall in aldosterone levels (P = 0.06) during treatment (median pretreatment, 446 pmol/l; median decrease, 125 pmol/l). However, the concurrent significant fall in the plasma sodium: potassium ratio indicated that changes in aldosterone secretion did occur. None of these effects on adrenal pathways was of a degree which is likely to have clinically relevant consequences. It is concluded that fadrozole hydrochloride achieves near maximal suppression of oestrogens at 1 mg bd, and that its effects on aldosterone synthesis are unlikely to be of clinical significance.

Presence of gonadotropin-releasing hormone and its messenger ribonucleic acid in human ovarian epithelial carcinoma

OBJECTIVE

The purpose of this study was to investigate the expression of gonadotropin-releasing hormone messenger ribonucleic acid and the presence of gonadotropin-releasing hormone in human ovarian carcinoma known to have gonadotropin-releasing hormone binding sites and to be affected by gonadotropin-releasing hormone analog.

STUDY DESIGN

Human ovarian carcinomas surgically removed and human ovarian carcinoma cell lines were examined. Gonadotropin-releasing hormone was determined by a radioimmunoassay and a bioassay. Gonadotropin-releasing hormone messenger ribonucleic acid was determined by reverse transcription polymerase chain reaction using oligonucleotide primers synthesized according to the published human gonadotropin-releasing hormone sequence.

RESULTS

Gonadotropin-releasing hormone was shown to be present in extracts of ovarian mucinous cystadenocarcinoma sample (0.8 +/- 0.12 pg/mg of protein) and ovarian adenocarcinoma cell line SK-OV3 (0.92 +/- 0.17 pg/mg of protein) but not in the normal ovary and placenta. Two of two extract samples from individual cases evoked dose-dependent phosphoinositide breakdown in rat granulosa cells similar to that caused by authentic gonadotropin-releasing hormone. Gonadotropin-releasing hormone messenger ribonucleic acid was detected in two of two mucinous cystadenocarcinoma specimens, one of one serous cystadenocarcinoma, and SK-OV3 cells but not in the dysgerminoma, mucinous cystadenoma, and normal ovary and placenta.

CONCLUSION

The demonstration of gonadotropin-releasing hormone and its messenger ribonucleic acid raises the possibility that gonadotropin-releasing hormone may play an autocrine regulatory role in the growth of ovarian carcinoma.

Hormone treatments in the common 'hormone-dependent' carcinomas

Current understanding of the mechanisms of action of hormonal therapies in carcinomas of the breast, prostate, endometrium and ovary is briefly reviewed. The range of available hormonal therapies for each disease is considered together with response rates, toxicity and any evidence for survival benefit. Practical guidelines for the palliative use of hormonal therapies are suggested.

Active cell death in hormone-dependent tissues

Active cell death (ACD) in hormone-dependent tissues such as the prostate and mammary gland is readily induced by hormone ablation and by treatment with anti-androgens or anti-estrogens, calcium channel agonists and TGF beta. These agents induce a variety of genes within the hormone-dependent epithelial cells including TRPM-2, transglutaminase, poly(ADP-ribose) polymerase, Hsp27 and several other unidentified genes. Not all epithelial cells in the glands are equally sensitive to the induction of ACD. In the prostate, the secretory epithelial cells that are sensitive to hormone ablation are localized in the distal region of the prostatic ducts, and are in direct contact with the neighboring stroma. In contrast, the epithelial cells in the proximal regions of the ducts are more resistant to hormone ablation, probably because the permissive effects of the stroma are attenuated by the presence of the basal epithelial cells, which are intercalated between the epithelium and stroma. The underlying biology of ACD in prostate and mammary glands, and its relevance to hormone resistance, is discussed in this review.

GnRH analogs in gynecological oncology: a review

Chronic GnRH analogs (GnRH-A) administration has proven to be effective for the control of some hormone-dependent tumors. GnRH-A are now in the standard treatment of prostatic cancer. In the present paper experimental and clinical data on the use of GnRH-A in gynecologic oncology are reviewed in order to identify a possible role in the therapy of breast, endometrial and ovarian cancer. Besides the indirect hormonal effect of GnRH-A, mediated by the suppression of gonadal steroidogenesis, in vitro evidence suggests a direct anti-proliferative action involving autocrine-paracrine regulation of cellular function. In advanced or recurrent breast cancer objective responses were observed in 157 out of 378 premenopausal patients (41%) and in 18 out of 166 postmenopausal women (10%). In ovarian cancer complete and partial responses were observed in 14 out of 121 (11%). At present, data on advanced endometrial carcinoma are limited: only 18 treated patients are reported, of whom 7 responded (38.8%). However, in general, most of the responses observed were transient. Thus, so far, the use of GnRH-A in gynecologic oncology has to be considered for palliation, after the failure of other better understood treatment modalities. The possible use of GnRH-A as an adjuvant is still under investigation.

Clinical pharmacokinetics of endocrine agents used in advanced breast cancer

Endocrine therapy is important in the treatment of advanced breast cancer. The prototype antiestrogen tamoxifen and the prototype aromatase inhibitor aminoglutethimide have been in clinical use for more than 2 decades, as have synthetic progestin derivatives. Currently, several novel antiestrogens and aromatase inhibitors are used to treat breast cancer. This paper reviews the present knowledge of the clinical pharmacokinetics of these drugs. Drug monitoring in plasma and other body fluids has been improved over recent years by the introduction of sensitive and specific high performance liquid chromatography and gas chromatography-mass spectrometry methods. However, we still lack information on such basic pharmacokinetic parameters as the bioavailability of several of these drugs. It is important to study not only plasma but also tissue drug concentrations.

A phase II trial of goserelin (Zoladex) in relapsed epithelial ovarian cancer

Thirty patients with advanced epithelial ovarian cancer were treated with the luteinising hormone releasing agonist, goserelin. There were two partial responses lasting 40 and 105 weeks respectively. In addition five patients had disease stabilisation lasting 25, 35, 40, 66 and 70 weeks respectively and 23 patients had progressive disease. No significant or unexpected toxicities occurred. This minimally toxic therapy halted disease progression for 6 months or more in 23% of patients, the majority of whom were heavily pretreated. There were five early deaths due to disease progression. The use of goserelin in patients with epithelial ovarian cancers resistant to or relapsing soon after first line platinum based chemotherapy needs to be further evaluated.

Inhibition of growth of MCF-7 MIII human breast carcinoma in nude mice by treatment with agonists or antagonists of LH-RH

Human breast carcinoma (MCF-7 MIII), which exhibits an estrogen-independent but estrogen-responsive phenotype, was xenografted in 8-9-week-old intact female athymic nude mice without estrogen supplementation. In this model, we investigated inhibitory effects of the modern luteinizing hormone-releasing hormone (LH-RH) antagonist SB-75 and the agonist D-Trp6-LH-RH. The analogs were administered in the form of sustained delivery systems (microcapsules and microgranules). In the first experiment, treatment lasted 10 weeks. After 9 weeks of treatment, a significant inhibition of tumor volume was first found only in the group treated with SB-75, but the final tumor volume was significantly suppressed both by D-Trp6-LH-RH and SB-75. In the second experiment, treatment was started 70 days after tumor transplantation and was continued for 6 weeks. Chronic treatment with SB-75 or D-Trp6-LH-RH appeared to completely arrest tumor growth as measured by tumor volume, percentage change in tumor volume, and tumor weight. Serum estradiol was suppressed to undetectable levels and LH levels were also diminished. Histologically, the regressive changes in the treated tumors were due to the enhancement of apoptosis (programmed cell death) of tumor cells. Membrane receptor assays showed that LH-RH binding sites were down-regulated in tumor cells after treatment with SB-75 or D-Trp6-LH-RH. The results indicate that the antagonist SB-75, released from sustained delivery systems, can inhibit the growth of MCF-7 MIII tumors as effectively as the agonist D-Trp6-LH-RH, but more rapidly. In view of its immediate blockade of the pituitary-gonadal axis and the absence of side effects, the LH-RH antagonist SB-75 might be considered as a possible new hormonal agent for the treatment of breast cancer.

Progestins in breast cancer treatment. A review

The two most widely used synthetic progestins in breast cancer treatment, medroxyprogesterone acetate (MPA) and megestrol acetate (MA), are reviewed with regard to pharmacological, endocrinological and clinical aspects. In high oral doses as second- or first-line endocrine therapy in advanced breast cancer, they give a similar response rate as tamoxifen (TAM) and aminoglutethimide (AG). The mechanism of action is probably complex. Considerable changes in serum levels of different hormones are induced by progestin treatment. The decrease of serum estrone sulfate (E1S) may be part of the therapeutic mechanism. Some studies suggest that the two drugs, MPA and MA, have a different mode of action, and possibly a low cross resistance. Randomized studies using the two progestins with a cross-over design may answer these questions. Further studies on the influence of progestin on different receptors and growth factors are warranted. To determine the most effective clinical dose of the two progestins, studies with increasing therapeutic doses are needed.

A new treatment for endometrial cancer with gonadotrophin releasing-hormone analogue

OBJECTIVE

To test the antitumour effect of gonadotrophin releasing-hormone (GnRH) analogues in women with recurrent endometrial cancer.

DESIGN

An open phase II observational trial of GnRH analogues. Serial measurements of gonadotrophins, sex hormones and tumour dimensions were made together with repeat biopsy when possible to assess the response to treatment.

SETTING

The outpatient clinics of the Department of Medical Oncology at The Royal London, Royal Marsden and St Bartholomew's hospitals.

SUBJECTS

17 patients with endometrial cancer which had recurred after surgery, radiotherapy and progesterone treatment and was symptomatic, progressive and assessable for response.

INTERVENTION

Monthly subcutaneous injection of GnRH analogue.

MAIN OUTCOME MEASURES

Reduction in serum gonadotrophins and reduction in tumour dimensions.

RESULTS

Six out of 17 patients (35%, 95% CI 12.6-58%) achieved a complete or partial remission which continues for a median of 20 months with no adverse effects.

CONCLUSION

GnRH analogues have a significant antitumour effect in recurrent endometrial cancer which warrants further examination in comparison with progestogens.

Goserelin. A review of its pharmacodynamic and pharmacokinetic properties, and clinical use in sex hormone-related conditions

Goserelin is a synthetic analogue of gonadotrophin-releasing hormone (GnRH) [luteinising hormone-releasing hormone (LHRH); or gonadorelin] which stimulates gonadotrophin and sex hormone release in the short term, and then causes suppression with continued administration. Goserelin is given as a subcutaneous biodegradable depot incorporating 3.6 mg of the drug, which is released continuously at an average rate of 120 micrograms/day over 4 weeks. Monthly goserelin depot therapy produces partial disease remission or stabilisation in about 75% of men with previously untreated prostatic cancer, a rate equivalent to that achieved with orchidectomy or diethylstilbestrol (stilboestrol). The response to goserelin is more rapid than to diethylstilbestrol, and goserelin is better tolerated. About 30 to 45% of premenopausal women with breast cancer responded to goserelin using objective assessment criteria, suggesting comparability to ovariectomy. In benign hormone-dependent conditions, preoperative goserelin aids surgical removal of uterine leiomyoma (fibroids) and reduces blood loss, and 6 months of therapy relieves the signs and symptoms of endometriosis. The elevation in testosterone at the beginning of goserelin therapy can result in disease 'flare' in men with prostate cancer, and sex steroid suppression with continued treatment results in hot flushes and loss of libido in most patients. Thus, goserelin is an effective alternative to surgery or estrogen therapy in prostatic cancer palliation, and possibly to ovariectomy in premenopausal breast cancer. Other gynaecological conditions reliant on the pituitary-gonadal axis also appear amenable to hormone manipulation with goserelin.

Influence of progestins on serum hormone levels in postmenopausal women with advanced breast cancer--I. General findings

The influence of oral high dose progestin (medroxyprogesterone acetate, MPA and megestrol acetate, MA) treatment on serum hormone levels was studied in ten postmenopausal women with advanced breast cancer. The gonadotropins and ACTH were significantly reduced by greater than 50 and 23%, respectively. Serum cortisol, DHEAS, androstenedione and testosterone were all significantly reduced (mean reduction between 64 and 76%), while serum estrone, estradiol and estrone sulfate were significantly reduced by 20-30%. Sex hormone binding globulin (SHBG) and corticosteroid binding globulin (CGB) were reduced by 68 and 25%, respectively. Although the dose of MA used (160 mg/day) was only 1/6 of the MPA dose (1000 mg/day), the mean serum level of MA was 2-fold higher than the mean serum level of MPA. MPA treatment gave a more pronounced suppression of SHBG than MA treatment, while estrone sulfate levels were more suppressed by MA. These findings suggest a differential effect of MPA and MA on certain plasma hormones, possibly of importance for understanding the mechanism of action of the two drugs. The reduction of estrone sulfate may be beneficial for the action of MA against breast cancer.

Postmenopausal estrogen synthesis and metabolism: alterations caused by aromatase inhibitors used for the treatment of breast cancer

Inhibition of postmenopausal estrogen production by aromatase inhibitors is an established drug treatment modality for postmenopausal breast cancer. In this article postmenopausal estrogen disposition and the alterations caused by treatment with aromatase inhibitors are reviewed. Recent investigations have challenged the hypothesis that aromatization of androstenedione into estrone is the sole production pathway for estrogens in postmenopausal women. The finding that estrogens persist in the plasma of patients receiving aminoglutethimide treatment despite a near total inhibition of the aromatase enzyme suggests that alternative pathways for estrogen synthesis exist. While nonspecific actions of aromatase inhibitors may be disadvantageous, certain effects may also be beneficial. Recent findings that aminoglutethimide may induce estrone sulfate metabolism questions whether this "prototype" aromatase inhibitor might have a dual mechanism of action. The importance of investigating the possible influence of different aromatase inhibitors on all components of estrogen disposition is considered.

New endocrine drugs for treatment of advanced breast cancer

Current status of endocrine treatment for breast cancer is reviewed. Several new aromatase inhibitors as well as antiestrogens are being introduced for clinical trials. As different drugs within the same drug group may possess different biochemical actions, apart from being useful drugs for treatment of breast cancer, these drugs may also extend our knowledge about the endocrinology of breast cancer.

Use of luteinising hormone-releasing hormone agonist (leuprorelin) in advanced post-menopausal breast cancer: clinical and endocrine effects

Fifteen post-menopausal patients with advanced breast cancer were treated with the LH-RH agonist leuprorelin (D-leu6-des-gly10-Gn-RH-ethylamide) given in a dosage of 7.5 mg as a monthly subcutaneous depot injection, to assess the clinical activity and endocrine response to treatment. None of the 15 patients showed an objective response to treatment, although four patients had stable disease for at least 6 months. No toxicity was demonstrated. Endocrine effects after 4 weeks' treatment were as follows: mean levels of serum gonadotrophins fell to 10% of their pretreatment values; there were no significant changes in the levels of prolactin on treatment; there was a significant decrease in the levels of serum testosterone in 12 out of 14 patients; there were no significant changes in the levels of oestradiol, androstenedione and oestrone. The lowering of serum testosterone suggests that androgens in post-menopausal women may be partly produced by the ovaries, stimulated by LH and FSH. This fall in testosterone may explain why some post-menopausal breast cancer patients in other studies have been reported to respond to treatment with LH-RH agonists, as it would decrease the substrate for the peripheral synthesis of oestrogens.