To the Editor

The treatment of symptomatic benign breast disease with danazol

A prospective randomized double blind trial, using danazol in a dose of 200 mg twice a day, was carried out on 80 women presenting with severe cyclical symptomatic benign mammary dysplasia. Standardized scores for 4 parameters of disease severity (breast pain, breast tenderness, breast nodularity and breast cysts) were defined and measured monthly on all patients admitted to the trial. Using nonparametric statistical analysis, significant improvement in breast pain, tenderness and nodularity, was found in both the double blind and crossover arms of the trial. An insufficient number of patients presented with breast cysts to draw any conclusions regarding the efficacy of danazol on cysts. Six months of treatment may produce a more sustained response, than 3 months of treatment. Danazol appears to be efficacious in managing patients with severe breast symptoms due to benign disease.

Danazol treatment of advanced prostate cancer: clinical and hormonal effects

Danazol was administered to 19 patients with advanced prostate cancer. These patients were treated for periods ranging from 3 days to 18 weeks. There were no objective remissions, but three patients (15.8%) had objectively stable disease (N.P.C.P. criteria) with complete pain control for periods ranging 15-18 weeks. Seven patients experienced tumor flare reactions, one requiring withdrawal of treatment and one resulting in rapid clinical deterioration and death. Four other patients died within 3 weeks and, although they were already in the terminal phase of disease when treatment commenced, it is possible that the deaths were treatment related. This study indicates that danazol has only limited activity in the treatment of advanced prostate cancer and is associated with a high incidence of tumor flare reactions with the risk of rapid clinical deterioration.

Ultrastructural changes in endometriotic tissue during danazol treatment

Electron microscopic examinations were carried out on 29 representative endometriotic glands obtained from 16 biopsies. Patients with endometriosis diagnosed by laparoscopy and confirmed by laparoscopic biopsy prior to hormonal treatment received danazol, 800 mg daily. The tissue samples were obtained after 2, 4, and 6 months of usage of the drug to study the ultrastructural effect of this treatment. The glandular epithelium appeared to be arrested in what looked like the late proliferative stage of the normal menstrual cycle. The ciliated cells remained unchanged for the most part. The findings were correlated with possible effects of danazol on the target tissue, but caution is required in the interpretation of ultrastructural effects of steroids until detailed knowledge of the metabolic pathways is available.

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.

Review: The mechanism of action of danazol, a novel steroid derivative

Danazol is being increasingly used for the treatment of a wide range of disorders, many of which appear to bear little relation to the condition for which the drug was originally marketed--endometriosis. It has been claimed that this drug acts by means of its antigonadotrophic effects on the pituitary; however, a review of the literature reveals that its efficacy in suppressing normal endometrial growth and in causing atrophy of deposits of endometrium cannot be explained solely on this basis. Recent information indicates that, besides acting at the pituitary level, a major mechanism of action may be by a direct inhibitory effect on target tissue. It is sugggested that such a mechanism would more readily account for the diverse effects of this drug in the treatment of many disorders, all of which appear to be associated with an imbalanced sensitivity of target organs to steroid hormones. A greater understanding of its mechanism of action could lead to an even wider application of this novel drug.