title: Prognostic significance of MCM 2 and Ki-67 in neuroblastic tumors in children.
abstract: BACKGROUND
  Neuroblastic tumors can be characterized by three features: spontaneous regression, maturation and aggressive proliferation. The most common and routinely used method of assessing tumor cell proliferation is to determine the Ki-67 index in the tumor tissue. Despite numerous studies, neuroblastoma biology is not fully understood, which makes treatment results unsatisfactory. MCM 2 is a potential prognostic factor in the neuroblastoma group.
  
  
  METHODS
  The study is based on retrospective analysis of 35 patients treated for neuroblastic tumors in the Department of Pediatric Surgery and Oncology of the Medical University of Lodz, during the period 2001-2011. The material comprised tissues of 16 tumors excised during the operation and 19 biopsy specimens. Immunohistochemical examinations were performed with immunoperoxidase using mouse monoclonal anti-MCM 2 and anti-Ki-67 antibodies.
  
  
  RESULTS
  We observed that MCM 2 expression ranged from 2% to 98% and the Ki-67 index ranged from 0 to 95%. There was a statistically significant correlation between expression of MCM 2 and the value of the Ki-67 index and a correlation close to statistical significance between expression of MCM 2 and unfavorable histopathology. There was no statistical relationship between expression of MCM 2 and age over 1 year and N-myc amplification.
  
  
  CONCLUSIONS
  The presented research shows that MCM 2 may have prognostic significance in neuroblastic pediatric tumors and as a potential prognostic factor could be the starting point of new individualized therapy.
authors.affiliation: Department of Pediatric Surgery and Oncology, Medical University of Lodz.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Lewandowska
authors.affiliation: Department of Pathology, Medical University of Lodz.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Taran
authors.affiliation: Department of Pediatric Surgery and Oncology, Medical University of Lodz.
authors.forename: Anna
authors.initials: A
authors.lastname: Sitkiewicz
authors.affiliation: Department of Pediatric Surgery and Oncology, Medical University of Lodz.
authors.forename: Ewa
authors.initials: E
authors.lastname: Andrzejewska
mesh_terms: D000293:Adolescent; D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D019394:Ki-67 Antigen / Q000032:analysis*; D008297:Male; D064111:Minichromosome Maintenance Complex Component 2 / Q000032:analysis*; D009447:Neuroblastoma / Q000175:diagnosis* / Q000378:metabolism; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; C084859:MCM2 protein, human; D064111:Minichromosome Maintenance Complex Component 2