One hundred and sixty patients with primarily inoperable breast cancer entered the preoperative chemotherapy protocol. The majority of patients (156) received chemotherapy according to the Cooper regimen (CMFVp), the remaining four were treated by the FAC regimen. Subsequently, mastectomy was performed in all patients. Postoperative treatment was chosen according to the hormonal status: premenopausal patients received chemotherapy (CMF), postmenopausal, hormonotherapy (tamoxifen). Overall 3 and 5-year survival rates were 58% and 38%, respectively. The degree of degeneration of cancer cells was estimated. Five-year overall survival rate in patients with significant cancer cell degeneration (greater than 75%) was higher, compared with patients without cancer cell degeneration (68% vs 33%, respectively P less than 0.002). We conclude that chemotherapy does not increase the rate of postoperative complications, and that the degeneration of cancer cells found in the specimen is an important factor with respect to improved survival.