This study focused on the correlation between tumor response and patient outcome in 329 breast cancers treated with primary chemotherapy. There were 141 stage IIIB tumors, including 109 inflammatory carcinomas. Other malignancies (34 IIIA, 99 IIB, 55 IIA) were operable but considered to be too large (> 3 cm) for conservative surgery and received primary chemotherapy to avoid mastectomy. All received the AVCF regimen, comprising 4-week cycles of doxorubicin (30 mg/m2) day 1, vincristine (1 mg/m2) day 1, 5-fluorouracil (5-FU; 400 mg/m2) days 2 through 5, cyclophosphamide (300 mg/m2) days 2 through 5. In 189 cases, methotrexate (15 mg/m2) was added at day 2 and day 3. Patients received 6 cycles, then underwent locoregional treatment (surgery, radiotherapy, or both) according to tumor regression. The response rate was assessed by clinical, mammographic, and echographic examinations: a 50% rate of objective responses were noted, of which 15% were complete responses (tumor shrinkage allowed breast conservation in 68% of patients who had stages II or IIIA). For the whole population studied, median follow-up was 111 months (range, 60- 196). One hundred fifty-seven patients had disease relapse (48 local, 14 contralateral, 95 distant). Kaplan-Meier estimates showed an increased 10-year overall survival for patients in complete response, as compared with noncomplete response: 70% versus 50% (p < 0.03). Complete response to neoadjuvant chemotherapy seems a good prognostic factor.