title: Cyclin A and cyclin D1 as significant prognostic markers in colorectal cancer patients.
abstract: BACKGROUND
  Colorectal cancer is a common cancer all over the world. Aberrations in the cell cycle checkpoints have been shown to be of prognostic significance in colorectal cancer.
  
  
  METHODS
  The expression of cyclin D1, cyclin A, histone H3 and Ki-67 was examined in 60 colorectal cancer cases for co-regulation and impact on overall survival using immunohistochemistry, southern blot and in situ hybridization techniques. Immunoreactivity was evaluated semi quantitatively by determining the staining index of the studied proteins.
  
  
  RESULTS
  There was a significant correlation between cyclin D1 gene amplification and protein overexpression (concordance = 63.6%) and between Ki-67 and the other studied proteins. The staining index for Ki-67, cyclin A and D1 was higher in large, poorly differentiated tumors. The staining index of cyclin D1 was significantly higher in cases with deeply invasive tumors and nodal metastasis. Overexpression of cyclin A and D1 and amplification of cyclin D1 were associated with reduced overall survival. Multivariate analysis shows that cyclin D1 and A are two independent prognostic factors in colorectal cancer patients.
  
  
  CONCLUSIONS
  Loss of cell cycle checkpoints control is common in colorectal cancer. Cyclin A and D1 are superior independent indicators of poor prognosis in colorectal cancer patients. Therefore, they may help in predicting the clinical outcome of those patients on an individual basis and could be considered important therapeutic targets.
authors.affiliation: Pathology Department, National Cancer Institute, Cairo University, Cairo, Egypt. chaya2000@hotmail.com
authors.forename: Abeer A
authors.initials: AA
authors.lastname: Bahnassy
authors.forename: Abdel-Rahman N
authors.initials: AR
authors.lastname: Zekri
authors.forename: Soumaya
authors.initials: S
authors.lastname: El-Houssini
authors.forename: Amal M R
authors.initials: AM
authors.lastname: El-Shehaby
authors.forename: Moustafa Raafat
authors.initials: MR
authors.lastname: Mahmoud
authors.forename: Samira
authors.initials: S
authors.lastname: Abdallah
authors.forename: Mostafa
authors.initials: M
authors.lastname: El-Serafi
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D003110:Colonic Neoplasms / Q000737:chemistry*; D019925:Cyclin A / Q000032:analysis*; D019938:Cyclin D1 / Q000032:analysis*; D004534:Egypt; D005260:Female; D006657:Histones / Q000032:analysis; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012004:Rectal Neoplasms / Q000737:chemistry*; D018709:Statistics, Nonparametric; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor; D019925:Cyclin A; D006657:Histones; D019394:Ki-67 Antigen; D019938:Cyclin D1