Evaluation of the cancer stem cell marker DCLK1 in patients with lymph node metastases of head and neck cancer

Background: Lymph node metastases are frequently detected in head and neck squamous cell carcinoma (HNSCC) patients. Little is known about biomarkers expressed in lymph node metastases or their influence on clinical outcome. Doublecortin-like kinase 1 (DCLK1) is one marker that might be associated with outcome, owing to its correlation with stem cell-like characteristics. Methods: We assessed the expression of DCLK1 in 74 postoperatively irradiated patients in histologically confirmed HNSCC lymph node metastases. Statistical analysis of the association with DCLK1 on clinical outcomes was performed. Results: DCLK1 was expressed in 63.5% of our patient cohort. DCLK1( + ) HNSCC patients, compared with those without DCLK1 expression, showed a significantly poorer time to recurrence. Moreover, we observed a significantly poorer time to recurrence in HPV( - ) HNSCC patients, and significantly shorter overall and disease-free survival rates in HPV( - ) oropharyngeal cancer patients, compared with HPV( + ) patients with these cancers. HPV ( + ) patients showed no significant differences in survival time according to DCLK1 expression. However, recurrent disease occurred in only DCLK1( + ) patients. Mulitivariate analysis showed that DCLK1 expression in lymph node metastases is an independent marker for recurrence. Conclusion: DCLK1 expression might be associated with poorer clinical outcomes in HNSCC patients, specifically in HPV( - ) move patients. However, larger studies are required to verify our results.