We did not observe a significant difference in overall allelic frequencies and genotype distribution of affected and unaffected mutation carriers {(A allele 0.533 for patients and 0.5 for controls; p = 0.41); (AA 30.21%, AG 46.22%, GG 23.57% for patients and AA 24.75%, AG 50.50%, GG 24.75% for controls; p = 0.29)}. However, the A allele frequency was higher (0.533) in our population than in numerous Caucasian populations (0.41-0.43) [16] (Table 2). No significant correlation was found between the CCND1 genotype and Dukes stage, tumor differentiation or location, or preoperative carcinoembryonic antigen (CEA) level.

When the patients were stratified according to gender, age and MSI status (Tables 3 and 4), we detected statistically significant risk of CRC in MSIpositive carriers of the CCND1 A allele (OR 2.3644; 95% CI: 1.0291<OR <5.4327; p = 0.0396) and MSIpositive carriers of the CCND1 A allele under 60 years of age (OD 3.8; 95% CI: 1.3516<OR<10.6837; p = 0.0082), which confirmed our previous results [19]. Most of this effect was confined to male patients with MSI-positive tumors (OD 5.5873; 95% CI: 1.6794<OR<18.5886; p = 0.0034) and in particular, male patients with MSI-positive tumors under 60 years of age (OD 10.6667; 95% CI: 2.3767<OR<47.8728; p = 0.0006). These trends were not observed in the female patients.