Genetic variants in cell cycle control pathway confer susceptibility to aggressive prostate carcinoma.

BACKGROUND: Because a significant number of patients with prostate cancer (PCa) are diagnosed with disease unlikely to cause harm, genetic markers associated with clinically aggressive PCa have potential clinical utility. Since cell cycle checkpoint dysregulation is crucial for the development and progression of cancer, we tested the hypothesis that common germ-line variants within cell cycle genes were associated with aggressive PCa. METHODS: Via a two-stage design, 364 common sequence variants in 88 genes were tested. The initial stage consisted of 258 aggressive PCa patients and 442 controls, and the second stage added 384 aggressive PCa Patients and 463 controls. European-American and African-American samples were analyzed separately. In the first stage, SNPs were typed by Illumina Goldengate assay while in the second stage SNPs were typed by Pyrosequencing assays. Genotype frequencies between cases and controls were compared using logistical regression analysis with additive, dominant and recessive models. RESULTS: Eleven variants within 10 genes (CCNC, CCND3, CCNG1, CCNT2, CDK6, MDM2, SKP2, WEE1, YWHAB, YWHAH) in the European-American population and nine variants in 7 genes (CCNG1, CDK2, CDK5, MDM2, RB1, SMAD3, TERF2) in the African-American population were found to be associated with aggressive PCa using at least one model. Of particular interest, CCNC (rs3380812) was associated with risk in European-American cohorts from both institutions. CDK2 (rs1045435) and CDK5 (rs2069459) were associated with risk in the African-American cohorts from both institutions. Lastly, variants within MDM2 and CCNG1 were protective for aggressive PCa in both ethnic groups. CONCLUSIONS: This study confirms that polymorphisms within cell cycle genes are associated with clinically aggressive PCa. Validation of these markers in additional populations is necessary, but these markers may help identify patients at risk for potentially lethal carcinoma.

Association of CASP8 D302H polymorphism with reduced risk of aggressive prostate carcinoma.

BACKGROUND: Because of the dramatically different clinical course of aggressive and indolent prostate carcinoma (PCa), markers that distinguish between these phenotypes are of critical importance. Apoptosis is an important protective mechanism for unrestrained cellular growth and metastasis. Therefore, dysfunction in this pathway is a key step in cancer progression. As such, genetic variants in apoptosis genes are potential markers of aggressive PCa. Recent work in breast carcinoma has implicated the histidine variant of CASP8 D302H (rs1045485) as a protective risk allele. METHODS: We tested the hypothesis that the H variant was protective for aggressive PCa in a pooled analysis of 796 aggressive cases and 2,060 controls. RESULTS: The H allele was associated with a reduced risk of aggressive PCa (OR(per allele) = 0.67, 95% CI: 0.54-0.83, P(trend) = 0.0003). The results were similar for European-Americans (OR(per allele) = 0.68; 95% CI: 0.54-0.86) and African-Americans (OR(per allele) = 0.61; 95% CI: 0.34-1.10). We further determined from the full series of 1,160 cases and 1,166 controls in the Prostate, Lung, Colorectal, Ovarian (PLCO) population that the protective effect of the H allele tended to be limited to high-grade and advanced PCa (all cases OR(per allele) = 0.94; 95% CI: 0.79-1.11; localized, low-grade disease OR(per allele) = 0.98; 95% CI: 0.79-1.23; and aggressive disease OR(per allele) = 0.73; 95% CI: 0.50-1.07). CONCLUSION: These results suggest that histidine variant of CASP8 D302H is a protective allele for aggressive PCa with potential utility for identification of patients at differential risk for this clinically significant phenotype.

Association between polymorphisms in cell cycle genes and advanced prostate carcinoma.

BACKGROUND: Single nucleotide polymorphisms (SNPs) have been associated with a variety of malignancies including prostate carcinoma (PCa). Since a high percentage of PCa patients have low risk disease, of particular interest is not whether SNPs are associated with localized PCa, but whether they are associated with aggressive, potentially lethal disease. Herein, we explored the role of SNPs in cell cycle genes to determine if they were associated with advanced PCa. METHODS: Nine previously implicated SNPs in six cell cycle genes were evaluated in a European-American cohort of 186 patients with advanced PCa and 222 cancer-free controls. All patients received hormone ablation and had either a PSA>50 ng/ml or documented metastatic disease. Controls were all 75 years of age or older, had a negative DRE and had a PSA<4.0 ng/ml. All genotypes were determined using Pyrosequencing assays. RESULTS: One of nine (CDKN1A c10791t) was statistically different (P<0.05) and an additional two of nine (CCND1 a870g and MDM2 tSNP309g) approached significance (P<0.1). Analysis of genotypes revealed that presence of at least one copy of the t allele of MDM2 tSNP309g was associated with an increased risk of advanced PCa (OR 2.26: 95% CI=1.15-4.46) which was particularly strong in androgen-independent disease (OR 2.28: 95% CI=1.01-5.12) and younger age of diagnosis (OR 2.61: 95% CI=1.05-6.46). CONCLUSION: These results suggest that in a European-American population, SNPs within cell cycle genes are promising markers for aggressive PCa. Larger studies will be needed to confirm these findings.