title: DCLK1 immunoreactivity in colorectal neoplasia.
abstract: BACKGROUND
  Microtubule-associated doublecortin and CaM kinase-like-1 (DCLK1) is a novel candidate marker for intestinal stem cells. The aim of our study was to assess DCLK1 immunoreactivity in colorectal carcinogenesis and its correlation with prognosis.
  
  
  METHODS
  DCLK1 immunostaining was performed in colorectal tissue from 71 patients, including 18 adenomatous polyps, 40 primary adenocarcinomas, and 14 metastatic lesions. Each case was evaluated by a combined scoring method based on the intensity of staining (score 0-3) and the percentage of tissue staining positive (score 0-3). Immunoexpression for DCLK1 was considered as positive when the combined score was 2-6 and negative with a score of 0-1.
  
  
  RESULTS
  Overall, 14/18 (78%) of polyps, 30/40 (75%) of primary adenocarcinomas, and 7/14 (50%) of distant metastases were positive for DCLK1. In adenomatous polyps and primary cancer there was no association between DCLK1 staining score and tumor pathology. However, after curative colorectal cancer resection, patients whose tumor had a high (≥5) combined staining score had increased cancer-specific mortality compared to patients with low (0-4) staining score (hazard ratio 5.89; 95% confidence interval: 1.22-28.47; P = 0.027).
  
  
  CONCLUSIONS
  We found that DCLK1 is frequently expressed in colorectal neoplasia and may be associated with poor prognosis. Further studies are necessary to validate the use of DCLK1 as a prognostic marker.
authors.affiliation: Department of Surgery and Pathology, Tulane University, New Orleans, LA, USA.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Gagliardi
authors.forename: Monica
authors.initials: M
authors.lastname: Goswami
authors.forename: Roberto
authors.initials: R
authors.lastname: Passera
authors.forename: Charles F
authors.initials: CF
authors.lastname: Bellows