DCLK1 Expression in Colorectal Polyps Increases with the Severity of Dysplasia

Background: The expression of doublecortin-like kinase 1 (DCLK1) has been investigated in cancer; however not in precancerous adenomatous polyps. Materials and Methods: Immunohistological expression of DCLK1 was evaluated in various grades of adenomas, cancerous polyps, and hyperplastic polyps in resected human tissue specimens. Results: Ninety-two specimens were positive for DCLK1 and 134 were negative. Cancerous polyps showed a high DCLK1 positivity rate compared to adenomas (68.4% vs. 36.8%; p<0.01). The rate of DCLK1 positivity was not significantly different among the three grades of adenomas (mild, moderate, and severe). DCLK1 was highly positive in advanced adenomas than low risk adenomas (49.6% vs. 29.3%; p<0.01). Conclusion: The expression of DCLK1 was found in low-grade adenomas and increased with worsening severity of dysplasia. DCLK1 expression was highly observed in advanced adenomas, which had a clinically higher malignant potential.