• Department of Epidemiology, Harvard School of Public Health, Building 2, Room 249B, 655 Huntington Avenue, Boston, MA 02115, USA. slindstr@hsph.harvard.edu

BACKGROUND: Genetic variation in two members of the Toll-like receptor family, TLR4 and the gene cluster TLR6-1-10, has been implicated in prostate cancer in several studies but the associated alleles have not been consistent across reports.

METHODS: We did a pooled analysis combining genotype data from three case-control studies, Cancer of the Prostate in Sweden, the Health Professionals Follow-up Study, and the Prostate, Lung, Colon and Ovarian Cancer Screening Trial, with data from 3,101 prostate cancer cases and 2,523 controls. We did imputation to obtain dense coverage of the genes and comparable genotype data for all cohorts. In total, 58 single nucleotide polymorphisms in TLR4 and 96 single nucleotide polymorphisms in TLR6-1-10 were genotyped or imputed and analyzed in the entire data set. We did a cohort-specific analysis as well as meta-analysis and pooled analysis. We also evaluated whether the analyses differed by age or disease severity.

RESULTS: We observed no overall association between genetic variation at the TLR4 and TLR6-1-10 loci and risk of prostate cancer.

CONCLUSIONS: Common germ line genetic variation in TLR4 and TLR6-1-10 did not seem to have a strong association with risk of prostate cancer.

IMPACT: This study suggests that earlier associations between prostate cancer risk and TLR4 and TLR6-1-10 sequence variants were chance findings. To definitely assess the causal relationship between TLR sequence variants and prostate cancer risk, very large sample sizes are needed.