A total of 39 patients with breast cancer of stages I and II received breast-conservation treatment (BCT) combined with tamoxifen and systemic chemotherapy (CAF) from August 1989 to March 1993. All of these patients visited the outpatient clinic of the Department of Radiology of Kochi Medical School Hospital, with an obvious desire to undertake BCT. During this period, another two patients with the same desire were treated with modified radical mastectomy, because of obviously positive surgical margins in frozen sections obtained at surgery. The percentage of patients treated by BCT was, therefore, 95.1%. All of the patients were females, and their average age was 49.9 years. Thirty-six of these 39 patients underwent lumpectomy, and another three patients with large-sized tumor or suspected extensive intraductal component underwent quadrantectomy or wide local excision. Nineteen of these 39 patients who were over 70 years old or had no clinically detectable axillary lymph node swelling received tangential field radiotherapy to their ipsilateral axillary region instead of axillary dissection. At the end of May 1993, the mean follow-up time was 22.4 months. Until now, one patient (T2N1M0, stage IIB) has died of distant metastases of breast cancer to bone, liver, lung, and brain, and another patient, aged 81, died of pneumonia with no evidence of breast cancer progression. The overall survival rates were, therefore, 100% (30/30), 90.0% (18/20), and 75.0% (6/8) at 1 year, 2 years, and 3 years, respectively. Cause-specific survival rates were 100% (30/30), 94.7% (18/19), and 85.7% (6/7) at 1, 2, and 3 years, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)