Cyclical mastopathy: a critical review of therapy.

Because of a recently completed trial which demonstrated that dietary fat reduction improved the symptoms of cyclical mastopathy, we have carried out a critical review of other studies of treatment for this disorder to determine what, if any, mechanisms of action were shared by effective treatments. Therapies were classified as 'definitely effective' if their effectiveness was demonstrated in at least one randomized placebo-controlled study of women with cyclical mastopathy, 'probably effective' if their effectiveness in relieving breast symptoms was demonstrated in at least one study in women with premenstrual syndrome, and 'probably not effective' if they had not been shown to improve breast symptoms in at least two studies in women with premenstrual syndrome. Bromocriptine, danazol, evening primrose oil, tamoxifen and reduction of dietary fat intake were classified as definitely effective and norethisterone and Bellergal as probably effective. Several therapeutic manoeuvres, including reduction of methylxanthine ingestion and the administration of vitamin E or diuretics, have not been adequately evaluated in women with cyclical breast symptoms. A review of the published reports of the physiological effects of therapies that were definitely or probably effective revealed that these agents acted either to alter serum prolactin levels or lipid metabolism, or both. As evidence exists that prolactin influences lipid metabolism it is postulated that cyclical mastopathy may be a disorder of lipid metabolism.