Eighty-three patients with rapidly progressing breast cancer (RPBC) were entered into a study of primary chemotherapy (cyclophosphamide, methotrexate, and 5-fluorouracil) and subsequent randomization to surgery or radiotherapy for control of local/regional disease. Eighty-three of these patients with redness, warmth, and edema compatible with clinical "inflammatory breast cancer" served as the focus for our analysis of factors associated with improved survival. The stage-specific disease-free intervals (DFI) of 36 and 21 months were substantially longer than in the earlier series (26 and 16 months) from the same institution. The evaluation of individual prognostic indicators revealed that the initial tumor size and the initial response to chemotherapy were the two independent factors most important in predicting the DFI. The continuing unmaintained 1-year remission in at least 12 patients supports the rationale for aggressive therapy in RPBC or "inflammatory breast cancer."