Tumour budding and the expression of cancer stem cell marker aldehyde dehydrogenase 1 in nasopharyngeal carcinoma

Luo W-R, Gao F, Li S-Y & Yao K-T ?(2012) Histopathology?Tumour budding and the expression of cancer stem cell marker aldehyde dehydrogenase 1 in nasopharyngeal carcinoma Aims: To detect the prognostic significance of tumour budding and its expression of aldehyde dehydrogenase 1 (ALDH1) in nasopharyngeal carcinoma (NPC). Methods and results: Tumour budding was investigated in 105 patients with NPC by immunohistochemistry for pan-cytokeratin (AE1/AE3). The intensity of budding correlated strongly with T classification (P = 0.008), lymphatic invasion (P < 0.001), vascular invasion (P = 0.029), lymph node metastasis (P < 0.001), and clinical stage (P = 0.010). Univariate analysis revealed that patients with high budding grade had poorer survival than those with low grade (P = 0.002). Multivariate analysis showed that tumour budding was an independent predictor of survival (P = 0.001). Furthermore, budding cells showed high-level expression of the cancer stem cell (CSC) marker ALDH1. Budding cells with high-level ALDH1 expression contributed to several aggressive behaviours and poor survival (P = 0.000). Conclusions: We describe, for the first time, the presence of tumour budding and its correlation with aggressive tumour behaviour and poor patient survival in NPC. The degree of tumour budding could be a valuable predictive factor in NPC. In addition, we show, also for the first time, that budding cells in NPC might possess the invasive and metastatic properties of CSCs.