The CCND1 gene (PRAD-1), located on chromosome band 11q13 [1], encodes one of the three cyclin D proteins, cyclin D1, which is expressed in most epithelial and fibroblast cells [2]. Cyclin D1 is a key regulatory protein in the transition from G1 to S phase of the cell cycle [2-5]. Amplification of the CCND1 gene and cyclin D1 over-expression were found in a variety of tumors, including those of the breast, head and neck, esophagus, larynx, lung and colorectum, and were correlated with poor outcome of the disease [6-11].

      A common GA polymorphism at nucleotide 870 of the CCND1 gene was described recently. This variant abolishes the normal donor splice site of intron 4, and results in the generation of an aberrant transcript which codes for a protein with a different COOH terminal domain [12]. This abnormal protein exhibits a longer half-life, presumably due to altered protein turnover, and thus makes the cells less sensitive to signals by the G1-S checkpoint machinery [13].

      Several conflicting reports were published on the clinical relevance of this polymorphism on the etiopathogenesis of colorectal cancer. Kong et al. [13] suggested that homozygosity for a G→A polymorphism in CCND1 is associated with increased risk of non syndromic (non familial adenomatous polyposis or Peutz - Jeghers syndrome) colorectal cancer at a young age. Their study was a follow-up of a previous work that indicated a dominant effect of the A allele on age of onset of cancer in families with hereditary non polyposis colorectal cancer (HNPCC) [14]. However, two other studies failed to demonstrate any association between the CCND1 genotype and patient survival [11,15].

      The aim of this study was to determine the effect of the CCND1 polymorphism in a group of colorectal cancer patients from the Republic of Macedonia.