AimsLarge operable cancers have traditionally been treated surgically by mastectomy. More recently centres have investigated the use of neoadjuvant chemotherapy to allow breast-conserving surgery. Between 1991 and 1995, a prospective study into the response of large operable breast cancers to CMF neoadjuvant chemotherapy was performed.MethodsPatients with cancers requiring mastectomy, and with or without clinically involved non-fixed lymph nodes, were offered neoadjuvant CMF chemotherapy. Patients declining neoadjuvant treatment underwent mastectomy and appropriate axillary surgery. Clinical response was assessed after two cycles in the neoadjuvant group. Subsequent surgical or non-surgical management was planned after this.ResultsThirty-eight patients were suitable for neoadjuvant treatment. Twenty-two underwent two cycles of CMF and were then reassessed. Seventy-three per cent achieved a response three (14%) complete remission, 13 (60%) partial remission. Fifteen (68%) patients avoided mastectomy, with six (27%) requiring no surgery at all with no clinically detectable residual disease. Sixteen (42%) declined neoadjuvant chemotherapy and opted for immediate mastectomy, seven of whom accepted chemotherapy post-operatively. After 3 years» follow-up there is no statistical difference in local recurrence, distant recurrence or overall survival.ConclusionApproximately 40% of patients offered neoadjuvant chemotherapy will demand prompt surgical treatment but will consider the use of adjuvant chemotherapy post-operatively. Sixty-eight per cent of patients receiving neoadjuvant CMF will successfully avoid mastectomy.