Treatment of fibrocystic disease of the breast with gestrinone, a new trienic synthetic steroid with anti-estrogen, anti-progesterone properties.

Twenty-eight patients with radiologically diagnosed fibrocystic disease were given twice weekly 5 mg tablets of Gestrinone, a synthetic contraceptive steroid with potent anti-estrogen, anti-progesterone properties, for periods ranging from 3 to 9 months. Treatment was discontinued when the nodularity disappeared and the patient became asymptomatic. Twelve patients had palpable nodules or masses in both breasts, while the remaining 16 had a single nodule or lump. In 12 patients, all with small nodules or lumps, complete elimination of nodularity occurred at the end of the first 3 months of treatment. In a further eight patients, five of whom had small nodules and three of whom had large ones, an additional 3 months of therapy were required to achieve complete elimination of nodularity. In two subjects, nodularity was eliminated at the end of 9 months of therapy, and in the remaining six subjects, although a reduction in nodularity greater than 50% occurred, masses remained palpable at the end of 9 months. Pain and tenderness were eliminated during the first 2 weeks of therapy in most cases. The most common complaints were acne and seborrhea (70% of patients) and a weight gain of between 2 and 5 kg in patients treated for 9 months. Main side effects encountered were acne and seborrhea.