[Adjuvant therapy of breast cancer]

The results of short-term intravenous adjuvant therapy with mitomycin C or cyclophosphamide in mastectomized cases were prospectively investigated. Statistically, this chemotherapy proved effective in cases without metastasis and in those with only 1 to 2 metastases in the axillary lymph nodes. With regard to menopausal status, this adjuvant systemic therapy was effective in premenopausal cases with statistical significance. In a trial, 1,000 cases of breast cancer were divided into two groups by the envelope method, and cyclophosphamide, 150 mg/day, was orally administered to one of the groups for 34 days (total dose, 5,100 mg) to investigate the utility of the chemotherapy in comparison with the control group not given adjuvant therapy. It was found that the adjuvant therapy was effective in cases with few metastases and that even the results obtained in cases with many metastases were better than in cases not given adjuvant therapy. In a preliminary trial, tamoxifen as an adjuvant endocrine therapy was orally administered at a daily dose of 20 mg for a prospective period of 3 years in advanced cases with 8 or more metastases in the axillary lymph nodes and the results over 1 to 2 years were analyzed. Improvement in therapeutic effect was found in these cases with 8 or more metastases in which previous adjuvant therapy had been ineffective.