Danazol therapy in hormone-sensitive mammary carcinoma

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.

Association of hereditary angioedema and hereditary breast cancer

A family is presented in whom hereditary angioedema (HAE) and hereditary breast cancer were coexistent, an association not previously reported. A potential for genetic and treatment-related interactions between the two conditions exists. The use of the hormonal agent danazol to suppress HAE is unlikely to adversely affect the development or outcome of breast cancer. Surgery, chemotherapy, and radiotherapy were received by affected family members, without triggering edema. Whether hormonal breast cancer treatment affects the suppression of HAE by danazol remains unknown.

The effect of danazol on tumour control and weight loss in patients on tamoxifen therapy for advanced breast cancer: a randomised double-blind placebo controlled trial

To assess the effect of danazol in advanced breast cancer 183 patients were randomised to receive either tamoxifen plus danazol or tamoxifen plus placebo. Patients underwent systemic work-up pretreatment then every 12 weeks or sooner if they clinically progressed. There were no differences in objective response rates with tamoxifen plus danazol vs. tamoxifen plus placebo (27% vs. 24%), time to progression (median 6.4 vs. 6.2 months) or survival (median 22.6 vs. 23.5 months) when the two arms were compared (all P > 0.5). The addition of danazol to tamoxifen had no effect on time to progression when adjusted for significant prognostic factors in a multivariate analysis. However, it was found incidentally that weight was stable on tamoxifen plus danazol (average gain 0.6 kg, S.E. 0.6 kg) compared with a significant loss on tamoxifen plus placebo (average loss 2.0 kg, S.E. 0.6 kg, P = 0.003). The average weight was maintained on tamoxifen plus danazol even in patients who did not respond to treatment.

Suppression of the development of uterine adenomyosis by danazol treatment in mice

Inhibitory effects of danazol, an isoxazol derivative of synthetic steroid 17 alpha-ethinyl-testosterone, on the development of uterine adenomyosis, a pathological disorder of endometrial tissue defined as the presence of endometrial glands and stroma in the myometrium, were investigated in mice of SHN strain. Mice treated with 0.5 microgram danazol for 5 weeks during 4-9 weeks of age and killed at 21 weeks of age showed significantly lower incidence of the spontaneous development of adenomyosis than the age-matched intact control mice. The inhibitory effects of danazol were also evident in mice bearing pituitary isografts which were effective in inducing an early and a high incidence of adenomyosis. Furthermore, the treatment with danazol resulted in the decrease of serum levels of luteinizing hormone (LH) and prolactin (PRL) associated with hypofunction of ovaries and persistent diestrus. These results support the usefulness of danazol for the clinical treatment of gynecological disorders except for hypofunction of ovaries.

Strategy of research for cancer—chemoprevention

It has been reported that environmental chemicals are important factors in terms of both development and prevention of human cancer. For the latter, detection of early stages is an essential first step followed by clinical trials for surveying populations at risk. Thus a great deal of attention has been focused on these areas. However, investigations of possibilities for active prevention of cancer development itself form another major project. Chemoprevention of carcinogenesis, which means prevention of carcinogenesis by exogenous chemical compounds, has been investigated extensively in a variety of organs in animal models. Usually attention is concentrated on only one organ. However, antioxidants, such as BHA, exert very different effects on different organs, suggesting the necessity of whole body approaches to the question of chemoprevention. Furthermore, the mechanisms of chemoprevention, including the step of carcinogenesis, i.e., initiation, promotion, progression or whole carcinogenesis steps, in which exogenous compounds exert their protective effects, should be considered. A medium-term bioassay system and a multi-organ carcinogenesis system, which can be used for investigation of potential for cancer chemoprevention, have been developed in our laboratory. Dose dependent inhibitory effects were established for both BHA and alpha-tocopherol in the medium-term bioassay system, and inhibition of small intestinal carcinogenesis by catechins in green tea has also been investigated in our multi-organ carcinogenesis protocol. It is extremely important for prevention of human cancer that we find new candidates for chemopreventive agents using animal studies. This paper reviews published reports on chemoprevention, taking into account effective stages, and proposes suitable experimental animal models for future investigations in this increasingly important area.

Effects of an androgenic derivative on pre-established mammary tumours chemically induced in the rat

The effects were studied of an androgenic derivative--danazol--administered at doses of 10-12 mg kg-1 day-1 during 97 days to rats with dimethylbenz[a] anthracene-induced mammary tumours. Our main observations were as follows. (a) Danazol did not influence ovarian function at the end of the assay. (b) The treatment with danazol reduced the incidence (P less than 0.05), number of tumours (P less than 0.05) and volume of malignant mammary tumours; on the other hand, the values of these parameters for benign tumours and those of doubtful expression were similar in both experimental groups. (c) Such differential action of Danazol seems to be due to the different incidence and/or content of receptors of both types of tumours. (d) The latter results lead to a hypothesis for the mechanism of action of danazol based on its behaviour at different levels.

Sulfate derivatives of 2-phenylindoles as novel steroid sulfataseinhibitors. An in vitro study on structure-activity-relationship

The growth of hormone-dependent mammary tumor cells is stimulated by non-conjugated estrogens. One important source of these hormones in the tumors could be the enzymatic hydrolysis of circulating estrogen sulfates by steroid sulfatase (EC 3.1.6.2). Inhibition of this enzyme may result in reduced levels of endogenous estrogens and, consequently, in a reduced proliferation rate of estrogen-dependent tumors. This paper reports on a series of inhibitors of steroid sulfatase based on sulfated derivatives of 2-phenylindoles, a new class of mammary tumor inhibiting compounds. Starting from hydroxy-substituted 2-phenylindoles, a number of mono- and disulfates were synthesized and tested for steroid sulfatase inhibiting properties. The enzymatic test was based on the measurement of [3H]estrone formed from [3H]estrone sulfate in the presence of various amounts of inhibitor. The concentrations which result in a 50% reduction of the rate of hydrolysis (IC50) were determined. Sulfates of hydroxylated 2-phenylindoles are substrates of steroid sulfatase. The most potent of these inhibitors show affinities which are comparable to the affinities of natural substrates. The test data further suggest that monosulfated compounds exhibit stronger enzyme-inhibiting properties than do disulfates.

Additive hormonal therapy in women with advanced breast cancer

A great deal of work has been done over the last decade in the assessment of additive hormonal treatment approaches in women with advanced breast cancer. This work has been prompted by a number of factors which include: (1) the introduction of new hormonal agents, (2) increased knowledge of the physiologic actions of several hormonal agents, (3) the development of hormonal receptor assays to better predict the probability of hormonal responsiveness in a given patient, and (4) the apparent plateau in efficacy of cytotoxic chemotherapeutic approaches. The hormonal agents that have been studied most extensively in the recent past include tamoxifen (an antiestrogen), aminoglutethimide (an aromatase inhibitor), and medroxyprogesterone acetate (a progestin). In postmenopausal women, several agents exist that appear about equal in efficacy; but, currently, tamoxifen appears to be preferred as the initial hormonal treatment, primarily because of its low incidence of side effects. Studies involving combination hormonal therapy have produced interesting results, but further work is needed to establish superiority over tamoxifen alone. In premenopausal women, tamoxifen does have antitumor activity in some patients but has not been established as a replacement for oophorectomy. Properly conducted comparative trials will remain essential for the determination of the proper place of newer hormonal therapy approaches in clinical practice.

Danazol for benign breast disease

Three groups of women with benign breast disease were treated with danazol for 3 to 6 months. Doses of 100 mg per day were given to 40 patients, 200 mg to 55, and 400 mg to 35. The age range of the patients was 20 to 48 years. The patients were rechecked at 6-month intervals over a period of 48 months. Most of them were seen four or more times after completion of therapy. Elimination of nodularity occurred in about two thirds; three experienced no improvement, and partial resolution was obtained in the remainder. Untoward effects were minimal or trivial. Danazol proved to be an excellent hormonal agent in the management of fibrocystic disease of the breast.