Expression of EMT markers and mode of surgery are prognostic in phyllodes tumors of the breast

Phyllodes tumors of the breast are rare neoplasms that account for <1% of all mammary tumors and 2-3% of fibro-epithelial neoplasms of the breast. We evaluated the clinicopathological characteristics of a cohort of 246 Chinese patients in relation to the expression of epithelial-to-mesenchymal (EMT) markers in benign, borderline and malignant tumors and the prognostic value of different surgical regimens. We observed that survival outcomes correlated with the mode of surgical management in the three patient groups. Expression of E-cadherin, Snail, Slug and Twist were higher in epithelial cells from borderline and malignant tumors than those in benign tumors, whereas the expression of N-cadherin was opposite. Levels of the EMT markers Snail and Slug in the stromal compartment increased with the advancing tumor grade. Expression of mesenchymal stem cell markers contributed to the inherent heterogeneity in the malignant tumors. Based on Cox models, surgical management emerged as an independent predictor for disease-free survival, whereas a history of recent growth and tumor grade were independent predictors for overall survival. These findings show that expression of EMT markers, the mode of surgical management, and a history of recent tumor growth had prognostic potential for patients with phyllodes tumors of the breast.