Background: Recently identified associations of prostate cancer risk with several genes involved in innate immunity support a role of inflammation in the etiology of prostate cancer. Considering inflammation is regulated by a complex system of gene products, we hypothesize sequence variants in many other genes of this pathway are associated with prostate cancer.
Methods: We evaluated 9,275 SNPs in 1,086 genes of the inflammation pathway using a MegAllele genotyping system among 200 familial cases and 200 unaffected controls selected from a large Swedish case-control population (CAPS).
Results: We found that significantly more than the expected numbers of SNPs were significant at a nominal P-value of 0.01, 0.05, and 0.1, providing overall support for our hypothesis. The excess was largest when using a more liberal nominal P-value (0.1); we observed 992 significant SNPs compared with the 854 significant SNPs expected by chance, and this difference was significant based on a permutation test (P = 0.0025). We also began the effort of differentiating true associated SNPs by selecting a small subset of significant SNPs (N = 26) and genotyped these in an independent sample of approximately 1,900 CAPS1 subjects. We were able to confirm 3 of these 26 SNPs. It is expected that many more true associated SNPs will be confirmed among the 992 significant SNPs identified in our pathway screen.
Conclusions: Our study provides the first objective support for an association between prostate cancer and multiple modest-effect genes in inflammatory pathways.
(c) 2006 Wiley-Liss, Inc.