Joint Swedish (Karolinska Institute) and US studypublished in NEJMreveals cummulative association of five (out of 16) previously known genetics variants (SNPs) with prostate cancer - three at 8q24 and one each at 17q12 and 17q24.3 (detailed tableand excellent summaryfrom SNPedia).
The idea was simple - it was known that each SNP has only a moderate association and effect wasn’t considered significant enough to justify testing individuals, but when SNPs are combined, the association may be stronger.
The study was carried out in Swedish men (2,893 prostate cancer cases and 1,781 control) and men who had any five or more of these factors associated with prostate cancer plus a family history of prostate cancer (i.e. hereditary/familial cancer), the odds ratio for prostate cancer was 9.46.
In other words, men with five or six of six risk factors, each SNP plus a family history of prostate cancer, were nearly 9.5 times more likely to have the disease.
Also, cumulative effect of these SNPs and family history was independent of PSA results.
Together, the five SNPs and family history were estimated to account for 46% of the cases of prostate cancer in the Swedish men studied. It is estimated that almost 90% of the Swedish population carries one or more of the five SNP, and the results should be tested in other populations.
Interestingly, the mechanism by which the analyzed SNPs could affect the risk of prostate cancer is still unknown.
Well, there is already commercial name for this test: Focus5™Prostate Cancer Risk Test(by freshProactive Genomics). [update]