Overexpression of DCLK1 is predictive for recurrent disease in major salivary gland malignancies.

Salivary gland carcinomas are a rare malignancy. Therefore, little is known about biomarkers and cancer stem cells in salivary gland malignancies. Double cortin-like kinase 1 (DCLK1) is a promising therapeutic target and cancer stem cell marker, predominantly investigated in pancreatic and colorectal cancer. The purpose of this study was to investigate the expression of DCLK1 in major and minor salivary gland carcinomas and its influence on survival. We examined a total of 80 patients with major or minor salivary gland cancer in this retrospective study. Immunohistochemistry with anti-DCLK1 antibody was applied to assess the expression of DCLK1. Moreover, we evaluated the impact of DCLK1 on overall and disease-free survival. DCLK1 expression could be detected in 66.3 % of all examined cases. Overexpression of DCLK1 was associated with reduced overall and disease-free survival in patients with major salivary gland cancer. Disease-free survival reached statistical significance (p = 0.0107). However, expression of DCLK1 had no influence on survival in patients with minor salivary gland cancer. Since treatment of recurrent disease in oncologic patients is utterly challenging, DCLK1 may be a promising prognostic biomarker that helps to identify patients with a high risk for recurrence of major salivary gland carcinoma.