High prevalence of HER-2/neu and p53 overexpression in inflammatory breast cancer.

BACKGROUND: Inflammatory breast cancer (IBC) is one of the most aggressive forms of breast cancer. Although the survival of patients with IBC has been greatly improved by the use of combined treatment modalities, women with IBC still have lower survival rates. We have summarized a single-center experience involving IBC patients. Our objectives are to clarify molecular alterations of HER-2/neu and p53 in IBC and to investigate the prognostic factors. METHODS: Between January 1990 and December 2000, 57 patients with IBC were referred to the Cancer Institute Hospital of the Japanese Foundation for Cancer Research. The incidence of IBC among primary breast cancers was 1.0% (57/5,757) in our hospital. Forty-six patients meeting Haagensen's criteria for inflammatory breast carcinoma were evaluated. All patients had biopsy-proven carcinomas but no distant metastases at referral. The median age at diagnosis for IBC was 51.8 (range, 28 to 70). All patients underwent a mastectomy. Chemotherapy was performed pre- or post-operatively. Three-year and 5-year survival rates were 56.5%, and 40.7%, respectively. Expressions of HER-2/neu and the p53 protein were determined retrospectively by immunohistochemical (IHC) staining of thin paraffin-embedded sections of primary tumors. RESULTS: Of 46 patients, 23 (50.0%) with tumors testing positive for HER-2/neu fared somewhat worse than those with negative tumors, but the differences were not significant for either overall survival (OS) or disease-free survival (DFS). Of 46 patients, 19 (41.3%) whose tumors were positive for p53 fared somewhat better than patients with negative tumors, with no significant differences in either OS or DFS. Patients presenting with less than ten pathologically involved axillary lymph nodes showed significantly better OS and DFS. CONCLUSIONS: Overexpression of HER-2/neu and the p53 protein were not significant prognostic factors in inflammatory breast cancer. However, the increased incidence of HER-2/neu and the poor outcome of IBC may be of clinical interest, suggesting the need for clinical trials of antibody therapy targeted to HER-2/neu. Moreover, a high prevalence of p53 may be useful in determining the specific use of chemotherapy.