Clinically relevant combined effect of polygenic background, rare pathogenic germline variants, and family history on colorectal cancer incidence

in BMC Medical Genomics (2023), 16(1), 42

Background and aims: Summarised in polygenic risk scores (PRS), the effect of common, low penetrant genetic variants associated with colorectal cancer (CRC), can be used for risk stratification. Methods ... [more ▼]

Background and aims: Summarised in polygenic risk scores (PRS), the effect of common, low penetrant genetic variants associated with colorectal cancer (CRC), can be used for risk stratification. Methods: To assess the combined impact of the PRS and other main factors on CRC risk, 163,516 individuals from the UK Biobank were stratified as follows: 1. carriers status for germline pathogenic variants (PV) in CRC susceptibility genes ( APC, MLH1, MSH2, MSH6, PMS2) , 2. low (\textless 20\%), intermediate (20–80\%), or high PRS (\textgreater 80\%), and 3. family history (FH) of CRC. Multivariable logistic regression and Cox proportional hazards models were applied to compare odds ratios and to compute the lifetime incidence, respectively. Results: Depending on the PRS, the CRC lifetime incidence for non-carriers ranges between 6 and 22\%, compared to 40 and 74 for carriers. A suspicious FH is associated with a further increase of the cumulative incidence reaching 26 for non-carriers and 98 for carriers. In non-carriers without FH, but high PRS, the CRC risk is doubled, whereas a low PRS even in the context of a FH results in a decreased risk. The full model including PRS, carrier status, and FH improved the area under the curve in risk prediction (0.704). Conclusion: The findings demonstrate that CRC risks are strongly influenced by the PRS for both a sporadic and monogenic background. FH, PV, and common variants complementary contribute to CRC risk. The implementation of PRS in routine care will likely improve personalized risk stratification, which will in turn guide tailored preventive surveillance strategies in high, intermediate, and low risk groups. [less ▲]

Breast and prostate cancer risk: the interplay of polygenic risk, rare pathogenic germline variants, and family history

in Genetics in Medicine (2021)

Purpose Investigate to which extent polygenic risk scores (PRS), pathogenic or likely rare pathogenic germline variants (PV), and family history jointly influence breast and prostate cancer risk. Methods ... [more ▼]

Purpose Investigate to which extent polygenic risk scores (PRS), pathogenic or likely rare pathogenic germline variants (PV), and family history jointly influence breast and prostate cancer risk. Methods 200,643 individuals from the UK Biobank were stratified as follows: 1. Heterozygotes or non-heterozygotes of PV in moderate to high cancer risk genes, 2. PRS strata, 3. with or without a family history of cancer. Multivariable logistic regression and Cox proportional hazards models were used to compute the odds ratio (OR) across groups and the cumulative incidence through life. Results Cumulative incidence by age 70 among non-heterozygotes across PRS strata ranged from 9% to 32% and from 9% to 35% for breast and prostate cancer, respectively. Among PV heterozygotes it ranged from 20% to 48% in moderate-risk genes and from 51% to 74% in high-risk genes for breast cancer, and it ranged from 30% to 59% in prostate cancer risk genes. Family history is always associated with an increased cancer OR. Conclusion PRS provides a meaningful risk gradient leading alone to a cancer risk comparable to PV in moderate risk genes while acting as risk modifier for high-risk genes. Including family history beside PV and PRS further improves cancer risk stratification. [less ▲]

Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease

in Nature Genetics (2017), 49