Genetic Risk Score:

A Tool for Calculating Prostate Cancer Risk

Categories: Winter 2017
Family history is a known risk factor for prostate cancer. However, family history only assigns prostate cancer risk to family members based upon the degree of relationship. For example, a man who has a first-degree relative (brother, father, son) with prostate cancer is considered to have a higher risk of prostate cancer than a man who has a second-degree relative (cousin, uncle, nephew, grandfather) affected by the disease.
Repeating patterns are found in the natural world and within the study of cancer. © Dan Oldfield

Dr. Catalona co-authored a study with his research collaborators, Drs. Brian Helfand and Jianfeng Xu of NorthShore Hospital in Chicago, seeking to determine if genetic risk scores (GRS) could better evaluate prostate cancer risk for men with a family history of the disease. The genetic risk scores were calculated by genotyping men for 26 genetic variants associated with prostate cancer. The researchers also assigned a degree of familial risk for prostate cancer, calculated based on prostate cancer cases in an individual’s family among first- versus second-degree relatives. Men from 811 families were included.

Variations in DNA sequences at specific locations are called singlenucleotide polymorphisms (SNPs). Large genetic studies have identified SNPs associated with prostate cancer. Dr. Catalona and his research group are responsible for some of these discoveries.

The study compared GRS scores among family members who were affected and unaffected by prostate cancer. Researchers found that the median GRS was significantly higher among men who were affected by prostate cancer. This was the case across all degrees of familial risk. This means that among men with similar degrees of familial risk of prostate cancer, genetic risk scores could be used to differentiate an individual’s risk for developing the disease. The GRS could also help guide a man’s decisions about when to start screening for prostate cancer, and how often to get tested. The authors noted that further validation studies are needed.

The study’s abstract was published in The Journal of Urology in April.


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