Increased risk of prostate cancer associated with AA genotype of cyclin D1 gene A870G polymorphism

CCND1 mRNA is alternatively spliced to produce 2 transcripts, and the splicing pattern may be modulated by a frequent A870G single-nucleotide polymorphism within the conserved splice donor site of exon 4. Several studies have suggested a significant association between the CCND1 genotype and onset or progression of various cancers. To investigate the correlation of the polymorphism with genetic susceptibility to PCa and its disease status, we examined the polymorphism in 214 cases of PCa, 234 cases of BPH and 254 male controls. The CCND1 A allele was more frequently observed in the PCa group (p = 0.015) and the BPH group (p = 0.018) than the control group. Men with the AA genotype had an increased risk of PCa (aOR = 1.93, 95% CI 1.13-3.30, p = 0.016) and BPH (aOR = 1.84, 95% CI 1.09-3.09, p = 0.023) compared to those with the GG genotype. No significant association was observed when men with the AG genotype were compared to those with the GG genotype (PCa: aOR = 1.00, 95% CI 0.65-1.54, BPH: aOR = 0.91, 95% CI 0.60-1.39). The risk of PCa associated with the AA genotype appeared to be stronger in men aged 73 years or younger (aOR = 2.89, 95% CI 1.38-6.01, p = 0.005), whereas no association was found in men older than 73 years (aOR = 1.02, 95% CI 0.44-2.34). No significant difference in genotype frequency was found among patients with low-, intermediate- and high-grade tumors (p = 0.730) or between patients with localized and metastatic PCa (p = 0.679). However, in patients with high-grade or metastatic PCa, a significantly increased risk associated with the AA genotype compared to controls was observed, while no significant results were found in those with low/intermediate or localized PCa. The A allele of the CCND1 A870G polymorphism was recessively associated with susceptibility to PCa and BPH in a Japanese population, giving a 2-fold increased risk of PCa and BPH in men with the AA genotype compared to those with the GG genotype. Although the risk of PCa associated with the AA genotype appeared to contribute especially to men aged 73 years or younger and the A allele may be associated with disease status of PCa, these conjectures require validation in future studies on a larger number of subjects.