Inflammatory breast carcinoma (IBC) is a rare and aggressive malignancy. Therapy for patients with IBC is multidisciplinary, and response to preoperative chemotherapy is considered an important predictor of outcome. Although only a limited number of molecular markers have been investigated in this setting, none has exhibited prognostic value for patients with IBC. Immunohistochemical assays for P53, MDM-2, and MUC-1 were performed retrospectively to evaluate potential correlations between these markers and pathologic response, time to progression (TTP), and overall survival (OS) in 19 patients with IBC. After a median follow-up period of 46 months, patients with tumors that overexpressed P53 and did not express MUC-1 had a significantly shorter median TTP and median OS compared with other patients. Expression of P53 and MUC-1 may be predictive of treatment efficacy and outcome for patients with IBC. Furthermore, these two markers may represent novel therapeutic targets in such patients. Copyright 2004 American Cancer Society.