[en] From 1978 through 1983, 27 patients were treated with surgery followed by irradiation (irradiated group) and 29 with surery alone (non-irradiated group). In the irradiated group, 10 had stage II and 17 stage III; in the non-irradiated group, 25 had stage II and 4 stage III. The most common histology was medullary tubular carcinoma (MTC). There was no significant difference in survivals at 3 years and 5 years between the groups. Similarly, no significant difference was seen among stage II patients. Patients with MTC tended to have worse survivals in the irradiated group than in the non-irradiated group, with no statistically significant difference. Among stage II patients, no major differences in local recurrence were seen between the groups; the incidence of distant metastases tended to be high in the irradiated group. The incidence of both local recurrence and distant metastases for stage III patients showed a tendency to be higher in the irradiated group than in the non-irradiated group. The results indicated no apparent benifit of postoperative irradiation for breast cancer. A randomized clinical trial is needed for the evaluation of postoperative irradiation for breast cancer. (Namekawa, K.)