P53 IN NODE-NEGATIVE BREAST-CARCINOMA - AN IMMUNOHISTOCHEMICAL STUDY OF EPIDEMIOLOGIC RISK-FACTORS, HISTOLOGIC FEATURES, AND PROGNOSIS

Purpose: The present study explores p53 in relation to the following f our aspects of node-negative breast carcinoma: epidemiologic risk fact ors, tumor histopathology, prognosis, and HER2/neu (HER) expression. M aterials and Methods: Immunohistochemical (IH) staining for p53 was pe rformed on formaldehyde-fixed, paraffin-embedded primary invasive carc inomas from 440 node-negative patients with a median follow-up duratio n of 119 months. Results: The IH expression, or lack thereof, of p53 s eparately or in combination with HER did not prove to be prognosticall y significant and there was no consistent association of p53 with epid emiologic risk factors, p53 was expressed in 68% of medullary carcinom as (MEDs), which is a significantly higher frequency (P < .001) than i n lobular (9%) and duct (23%) carcinomas, p53 was not found in some ty pes of law-grade carcinomas (tubular and papillary), and was observed in a minority of mucinous carcinomas, p53 was present significantly mo re often in carcinomas with high-grade or poorly differentiated nuclea r grade than in low- or intermediate-grade tumors. There was an invers e statistically significant relationship between estrogen receptor (ER ) positivity and p53 expression. Tumors with the p53(+)/HER(-) immunop henotype tended to be MEDs or duct carcinomas with a marked lymphoplas macytic reaction. Infiltrating lobular carcinomas (IFLCs) were largely p53(-)/HER(-). p53(+)/HER(+) carcinomas had the best prognosis. The p oorest outcome was associated with the p53(-)/HER(+) immunophenotype. This trend was statistically significant far recurrence-free and overa ll survival in patients with T1N0M0 infiltrating duct carcinoma (IFDC) . Conclusion: The IH demonstration of p53 was not a reliable prognosti c indicator in the node-negative breast carcinoma patients studied and it was not associated with major epidemiologic risk factors. The comb ined immunophenotypic expression of p53 and HER was significantly asso ciated with some histologic types of breast carcinoma and with prognos is in T1N0M0 breast carcinoma. J Clin Oncol 13:821-830, (C) 1995 by Am erican Society of Clinical Oncology.