NEW YORK (Reuters Health) – The presence of multiple single nucleotide polymorphisms (SNPs) associated with increased prostate cancer risk, coupled with a positive family history, accurately identify men at high risk for prostate cancer who might benefit from aggressive chemoprevention with agents such as finasteride.

That’s according to study findings reported at the American Association for Cancer Research (AACR) annual meeting in Denver.

In a prepared statement from the meeting, first author and study presenter Dr. Jianfeng Xu said: “This is the first time that we provided a simple tool for estimating absolute risk (for prostate cancer) based on multiple genetic variants in combination. Up until now, we knew that each of these variants carried a slightly increased risk, but in combination the risk prediction is much more reliable.”

In the study of 2,893 men with prostate cancer and 1,781 men without prostate cancer, Dr. Xu, of the Wake Forest University School of Medicine in Winston-Salem, North Carolina, and colleagues found that the risk of prostate cancer increased as the number of risk alleles increased.

Each additional risk allele was associated with an odds ratio for prostate cancer of 1.14 and this effect was strongest in men with a family history of prostate cancer.

Men who had at least 15 of the known risk alleles had a 34% risk of prostate cancer in the next 20 years, the team found, and this risk increased to 45% in men who also had a family history of prostate cancer.

By comparison, in the absence of this risk-allele information, the risk of prostate cancer among these men would have been estimated to be only 13%.

This method of risk assessment, Dr. Xu said, could be used to target men at very high risk for prostate cancer who might benefit from aggressive preventive measures such as diet/lifestyle intervention and chemoprevention. For example, Dr. Xu said, “we know that finasteride can reduce risk of prostate cancer by 25% in high risk men.”