Prospective comparison of family medical history with personal genome screening for risk assessment of common cancers

Family history-based risk assessment (FHRA) is a genetic tool for identifying those at risk of disease. Genome-wide association studies have shown that single nucleotide polymorphisms (SNP) are statistically associated with low- to moderate-level risks of diseases. There has been limited study of complementarity for these two assessment methods. We sought to compare cancer risk categorizations from FHRA and from Navigenics Personal Genome Screening (PGS). We compared FHRA with PGS for breast (22 females), prostate (22 males), and colon cancer (44 males and females) assessed by kappa (κ) statistic. We also assessed each participant's hereditary risk based on clinical criteria and/or gene-test results. Both FHRA and PGS placed 59%, 68% and 44% of participants into the same risk categories for breast, prostate, and colon cancer, respectively. Overall, however, there was little concordance in FHRA versus PGS for all three cancer risks (κ<0.2). FHRA assigned 22 with hereditary risk compared with PGS, which identified one as high risk (P<0.0001). We assessed nine with hereditary colorectal cancer risk, five with germline mutations, but none were classified as PGS high risk (P=0.0001). FHRA and PGS may be complementary tools for cancer risk assessment. However, evaluation of family history remains the standard to evaluate an individual's cancer risk until further research.