title: Cancer Stem Cell Gene Variants in CD44 Predict Outcome in Stage II and Stage III Colon Cancer Patients.
abstract: Growing evidence suggests that human cancers are stem cell diseases and recent data support the existence of cancer stem cells (CSCs) in a variety of malignancies, including colon cancer. These CSCs were shown to be capable of initiating tumor development and progression. Several studies have suggested CD133, CD26 and CD44 as markers of tumor-initiating cells of colon cancer. The purpose of the present study was to assess the impact of single-nucleotide polymorphisms (SNPs) in stem cell-related genes on clinical outcome in a large cohort of colon cancer patients with clinical stage II and III.
  
  
  
  Data from 599 consecutive patients with colon cancer stage II and III, treated between 1995 and 2011 at a single centre, were retrospectively evaluated. Genomic DNA was extracted from paraffin-embedded normal tissue distant from the tumor to obtain germline DNA. Allelic distribution of polymorphisms was tested for deviation from Hardy-Weinberg equilibrium using χ2-test. The association of polymorphisms with time to recurrence (TTR) and overall survival (OS) was analyzed using Kaplan-Meier curves and compared by the log-rank test. Case-wise deletion for missing polymorphisms was used in univariable and multivariable analyses.
  
  
  
  CD44 rs187115 showed a statistically significant association with TTR; patients carrying at least one G allele had a significant reduced risk of recurrence compared to patients with the homozygous A/A variant (hazard ratio (HR)=0.67, 95% confidence interval (CI)=0.48-0.94, p=0.019). CD44 rs13347 showed a statistically significant association with OS. Patients carrying at least one T allele in rs13347 had a significantly reduced risk of death compared to patients with the homozygous C/C variant (HR=0.61, 95% CI=0.41-0.92, p=0.019). None of the other investigated polymorphisms (CD44 rs187116, CD44 rs7116432, CD44 rs353639, DPP4 rs2268889, DPP4 rs3788979, DPP4 rs7608798 and CD133 rs2240688) were associated with either TTR or OS.
  
  
  
  Germline variants rs13347 and rs187115 in the stem cell gene CD44 are prognostically relevant in stage II and III colon cancer patients.
authors.affiliation: Division of Clinical Oncology, Department of Medicine, Medical University of Graz, Graz, Austria michael.stotz@medunigraz.at.|Research Unit Genetic Epidemiology and Pharmacogenetics, Division of Clinical Oncology, Medical University of Graz, Graz, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Stotz
authors.affiliation: Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria.
authors.forename: Sereina A
authors.initials: SA
authors.lastname: Herzog
authors.affiliation: Division of Clinical Oncology, Department of Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Pichler
authors.affiliation: Division of Clinical Oncology, Department of Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Maria
authors.initials: M
authors.lastname: Smolle
authors.affiliation: Division of Clinical Oncology, Department of Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Jakob
authors.initials: J
authors.lastname: Riedl
authors.affiliation: Division of Clinical Oncology, Department of Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Christopher
authors.initials: C
authors.lastname: Rossmann
authors.affiliation: Division of Clinical Oncology, Department of Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Angelika
authors.initials: A
authors.lastname: Bezan
authors.affiliation: Division of Clinical Oncology, Department of Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Herbert
authors.initials: H
authors.lastname: Stöger
authors.affiliation: Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Renner
authors.affiliation: Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria.
authors.forename: Andrea
authors.initials: A
authors.lastname: Berghold
authors.affiliation: Division of Clinical Oncology, Department of Medicine, Medical University of Graz, Graz, Austria.|Research Unit Genetic Epidemiology and Pharmacogenetics, Division of Clinical Oncology, Medical University of Graz, Graz, Austria.
authors.forename: Armin
authors.initials: A
authors.lastname: Gerger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics*; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000473:pathology; D009367:Neoplasm Staging; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; C497483:CD44 protein, human; D018960:Hyaluronan Receptors
keywords: CD44; Colon cancer; cancer stem cells; single-nucleotide polymorphisms