Medical castration using megestrol acetate and minidose estrogen

Megestrol acetate in pediatric oncology patients may lead to severe, symptomatic adrenal suppression

BACKGROUND

Despite the widespread use of megestrol acetate (MA) among a growing number of pediatric oncology departments, there is only one published study on the use of MA in children with malignant disease. The objectives of the current study were to examine the effect of MA in improving the nutritional status of children with malignant disease and to describe and consider the implications of MA-associated adrenal suppression that was found consistently.

METHODS

Medical records of 19 children with malignant disease who were treated with MA were reviewed. During MA therapy, clinical assessments every 4 weeks included anthropometrics, caloric intake, quality-of-life scores, and appetite scores. Serum cortisol levels, lipid profiles (including cholesterol levels) random blood glucose levels, and coagulation screening were measured at 4-6-week intervals.

RESULTS

MA use was associated with significant increases in weight, weight z score, middle-upper arm circumference, triceps skin-fold thickness, appetite, and caloric intake. MA was extremely useful in aiding the efficient tapering of nasogastric feeds. However, a significant and potentially dangerous decrease in cortisol was seen in 10 of 11 patients tested, with 1 patient who manifested clinical hypoadrenalism with hemodynamic collapse, requiring inotropic support. This is the first report of MA-associated clinical adrenal suppression in a child with malignant disease.

CONCLUSIONS

Although the results of this study support the ability of MA to improve nutritional status, its use was complicated by severe adrenal suppression in almost all patients tested, with a serious clinical adverse event occurring in one patient. Routine hydrocortisone supplementation throughout MA treatment should be considered as well as larger doses for patients with acute illness and patients who undergo surgery.

Will the experience with tamoxifen in breast cancer help define the role of antiandrogens in prostate cancer?

Breast and prostate cancers are the two predominant hormone-responsive tumours. The use of the antioestrogen tamoxifen in the treatment of breast cancer has evolved over the past 30 y from treatment for advanced breast cancer to prevention. Tamoxifen is currently the endocrine treatment of choice for advanced breast cancer and for adjuvant therapy in a broad spectrum of women whose primary tumours have functional oestrogen receptors. It has also been shown to reduce the incidence of breast cancer in high-risk women. Non-steroidal antiandrogen therapy is used in the treatment of prostate cancer, but its role is still being defined. The clinical development of tamoxifen and that of the antiandrogens are reviewed and parallels are uncovered which provide insight into contemporary and future management of hormone-responsive prostate cancer.Prostate Cancer and Prostatic Diseases (2001) 4, 72-80

Hormonal treatment for prostate cancer

For nearly six decades the preferred primary treatment for advanced prostate cancer has been continuous suppression of testicular androgen production by medical or surgical castration. While androgen deprivation is effective in inducing tumour regression in the large majority of cases, essentially all patients will develop progressive disease. In addition androgen deprivation may be associated with a variety of side effects. Thus, strategies that minimise the use of these agents could potentially lower the morbidity and cost associated with the treatment of advanced prostate cancer. In the era of prostate-specific antigen (PSA) testing, hormonal therapy is being used earlier in the course of the disease when the only evidence of recurrent disease is an elevated PSA. These men may survive for many years and thus have the potential for long periods of exposure to hormonal therapy and its side effects. It has been hoped that the development of alternative hormonal interventions might lead to both enhanced antitumour efficacy as well as improvements in side effect profile.

How is androgen-dependent metastatic prostate cancer best treated?

The principles of management of newly diagnosed metastatic prostate cancer have changed little since the time of Huggins and his colleagues. Modern clinicians have many more weapons in their therapeutic armamentarium than those pioneers, but little progress has been made in improving the survival of men with this disease. The results of androgen deprivation are comparable using any one of a number of different monotherapy approaches. The use of combined androgen blockade may improve survival in men with minimal disease but at considerable economic cost and with significant impairment of quality of life. The benefit of this therapy for men with more extensive disease is uncertain. New modalities such as intermittent androgen blockade or combination therapies are exciting, but unproven.

Megestrol-induced Cushing's syndrome

This case describes the first report of a patient developing Cushing's syndrome whilst being treated with the synthetic progestogen, megestrol acetate (Megace). Drugs are the commonest cause of Cushing's syndrome. Some synthetic progestogens are known to have glucocorticoid activity at high doses. On structural grounds neither megestrol nor its major metabolites would be expected to interact with the glucocorticoid receptor, through the manufacturers report that it may have 'weak glucocorticoid activity'.

Management of symptomatic lymphocele via percutaneous drainage and sclerotherapy with tetracycline

Lymph collections following pelvic surgery are usually asymptomatic, but may occasionally produce symptoms requiring invasive therapy. We have successfully obliterated a large lymphocele by employing percutaneous drainage and instilling tetracycline.

Systemic management of prostate cancer

The objective of this review is to explore different therapeutic options for metastatic adenocarcinoma of the prostate. Orchiectomy, estrogen therapy, synthetic LHRH analogs and possibly antiandrogens are equally effective frontline treatment modalities. Ketoconazole is indicated in emergency situations, but chronic use is prevented by serious idiosyncratic toxicity and by long term complications. Combined androgen blockade (CAB), with leuprolide (or tryptorelin) and flutamide is more effective than single modality treatment in patients capable of strict treatment compliance. Estramustine phosphate may be as effective as CAB and may be the frontline treatment of choice in sexually active patients. Institution of single modality treatment may be delayed until cancer becomes symptomatic. Controversy lingers over whether the institution of CAB at an earlier time may improve progression free survival (PFS) and survival. Research projects of immediate clinical relevance include: comparison of CAB and estramustine; determination of the optimal time for CAB; study of other forms of CAB; and phase II trials of new cytotoxic agents.

Induction of chemical castration in male rats by a new long-acting LHRH-antagonist

LHRH-antagonists might represent a useful new type of androgen deprivation to treat prostatic cancer. In this context adult intact male rats were treated subcutaneously with different concentrations of the new LHRH-antagonist antide either once (1, 3, 6, 10, 15 mg/kg) or on 5 consecutive days (5 x 3 mg/kg). The effect on serum concentration of LH and testosterone and the effect on the weights of testes, prostate, and seminal vesicles was investigated after different periods of time (24 hours, 1, 2, 3, 5, and 8 weeks). Histological evaluation of the testes was also performed. A clear dose-dependent inhibitory effect on the above-mentioned parameters was observed. The most effective treatment schedule was the single application of 15 mg/kg resulting in castration-like inhibition of prostate weights and marked inhibition of spermatogenesis within 2 weeks, which was maintained 8 weeks after the injection. Serum LH and serum testosterone concentrations were below the detection limit of the assay within 2 weeks and showed first signs of recovery after 8 weeks. Histologically, no signs indicative of irreversible effects (testes) were observed. To summarize, the LHRH-antagonist antide was found to have a profound long-lasting inhibitory but reversible effect on the reproductive system of adult intact male rats. These data emphasize the suitability of this type of compound for the treatment of prostatic cancer.

Hormonal therapy for prostate cancer

Since the demonstration in 1941 by Huggins and Hodges that prostatic cancers are androgen dependent, hormonal treatment by androgen ablation has been the principal treatment for patients with advanced adenocarcinoma of the prostate. Although not able to permanently and totally eradicate every cancer cell since prostate cancer cells are quite heterogeneous in their sensitivity to androgens, hormonal therapy can produce dramatic subjective improvement as well as objective remissions. This results in an improved quality of survival and for patients with metastatic adenocarcinoma, endocrine therapy does reduce the death rate from cancer, and if death from other concurrent illness is controlled, there is an absolute increase in survival. At present, a variety of strategies are available for ablation of testicular and adrenal androgens, but results are not clinically significantly better than orchiectomy.