Expression of cell polarity protein scribble differently affects prognosis in primary tumor and lymph node metastasis of breast cancer patients.

ABSTRACT

BACKGROUND: We evaluated the relationship between the immunohistochemically determined expression of the cell polarity protein scribble to prognosis in different environments of estrogen receptor (ER) expression and epithelial-to-mesenchymal transition (EMT). METHODS: We immunohistochemically evaluated the expression level of scribble in primary tumors and lymph node metastases of 225 node-positive breast cancer patients who had received chemotherapy. We then evaluated metastasis-free survival (MFS) in the absence or presence of ER and the EMT-related protein vimentin. RESULTS: Among patients with ER-positive tumors, patients with low scribble expression in the primary tumor had a significantly shorter MFS than patients with high scribble expression (p = 0.0225). Furthermore, among patients with vimentin-negative tumors, patients with low expression of scribble in the primary tumor had significantly shorter MFS than patients with high expression of scribble (p = 0.0463). In contrast, among patients with vimentin-positive tumors, patients with high expression of scribble in the primary tumor had significantly shorter MFS than patients with low expression of scribble (p = 0.0343). Moreover, among patients with ER-negative tumors, patients with high expression of scribble in lymph node metastases showed significantly higher expression of E-cadherin in metastases (p = 0.0407) and had significantly shorter MFS than patients with low expression of scribble (p = 0.0064). CONCLUSIONS: The prognostic significance of cell polarity depended on the ER expression and EMT. Furthermore, the preservation of cell polarity in metastases was associated with mesenchymal-to-epithelial transition and worse prognosis. Cell polarity promotes the diversity of metastasis in combination with malignancy grade in breast cancer patients.