Expression of CD44 isoforms in infiltrating lobular carcinoma of the breast

Expression of CD44 has been shown to correlate with the progression and pro gnosis of some malignant tumors. The aim of this study was to evaluate the expression of CD44 isoforms in infiltrating lobular carcinomas and analyse their potential as prognostic indicators. A panel of 39 tumors were examine d for their expression of membranous and cytoplasmic CD44s, v3, v5, v6, v7 and v3-10 in the infiltrating cells, by immunohistochemical staining. The p rotein positive tumors showed membranous and/or cytoplasmic staining with a ll antibodies used except for CD44v7, which only displayed cytoplasmic stai ning. Cytoplasmic expression of CD44v3 (P = 0.014) and membranous expressio n of v6 (P = 0.039) were significantly associated with alveolar, classical/ alveolar carcinomas and mucinous/alveolar carcinomas. Furthermore, in alveo lar, classical/alveolar and mucinous/alveolar carcinomas, cytoplasmic stain ing of CD44v5 was correlated with lymph node negative patients (P = 0.048), whereas membranous v5 was correlated with lymph positive patients (P = 0.0 48). In classical, classical/trabecular and trabecular carcinomas expressio n of membranous CD44s was significantly correlated with lymph node status ( P = 0.042).