Population-standardized genetic risk score: the SNP-based method ofchoice for inherited risk assessment of prostate cancer

摘要

Several different approaches are available to clinicians for determining prostate cancer (PCa) risk. The clinical validity of various PCa risk assessment methods utilizing single nucleotide polymorphisms (SNPs) has been established; however, these SNP-based methods have not been compared. The objective of this study was to compare the three most commonly used SNP-based methods for PCa risk assessment. Participants were men (n = 1654) enrolled in a prospective study of PCa development. Genotypes of 59 PCa risk-associated SNPs were available in this cohort. Three methods of calculating SNP-based genetic risk scores (GRSs) were used for the evaluation of individual disease risk such as risk allele count (GRS-RAC), weighted risk allele count (GRS-wRAC), and population-standardized genetic risk score (GRS-PS). Mean GRSs were calculated, and performances were compared using area under the receiver operating characteristic curve (AUC) and positive predictive value (PPV). All SNP-based methods were found to be independently associated with PCa (all P < 0.05; hence their clinical validity). The mean GRSs in men with or without PCa using GRS-RAC were 55.15 and 53.46, respectively, using GRS-wRAC were 7.42 and 6.97, respectively, and using GRS-PS were 1.12 and 0.84, respectively (all P < 0.05 for differences between patientswith or without PCa). All three SNP-based methods performed similarly indiscriminating PCa from non-PCa based on AUC and in predicting PCa risk based on PPV(all P > 0.05 for comparisons between the three methods), andall three SNP-based methods had a significantly higher AUC than family history (allP < 0.05). Results from this study suggest that while thethree most commonly used SNP-based methods performed similarly in discriminating PCafrom non-PCa at the population level, GRS-PS is the method of choice for riskassessment at the individual level because its value (where 1.0 represents averagepopulation risk) can be easily interpreted regardless of the number ofrisk-associated SNPs used in the calculation.