The predictive ability of the 313 variant–based polygenic risk score for contralateral breast cancer risk prediction in women of European ancestry with a heterozygous BRCA1 or BRCA2 pathogenic variant

OCGN Investigators, HEBON Investigators, KConFab Investigators, GEMO Study Collaborators, EMBRACE Collaborators

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12 Citations (Scopus)

Abstract

Purpose: To evaluate the association between a previously published 313 variant–based breast cancer (BC) polygenic risk score (PRS 313) and contralateral breast cancer (CBC) risk, in BRCA1 and BRCA2 pathogenic variant heterozygotes. Methods: We included women of European ancestry with a prevalent first primary invasive BC (BRCA1 = 6,591 with 1,402 prevalent CBC cases; BRCA2 = 4,208 with 647 prevalent CBC cases) from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), a large international retrospective series. Cox regression analysis was performed to assess the association between overall and ER-specific PRS 313 and CBC risk. Results: For BRCA1 heterozygotes the estrogen receptor (ER)-negative PRS 313 showed the largest association with CBC risk, hazard ratio (HR) per SD = 1.12, 95% confidence interval (CI) (1.06–1.18), C-index = 0.53; for BRCA2 heterozygotes, this was the ER-positive PRS 313, HR = 1.15, 95% CI (1.07–1.25), C-index = 0.57. Adjusting for family history, age at diagnosis, treatment, or pathological characteristics for the first BC did not change association effect sizes. For women developing first BC < age 40 years, the cumulative PRS 313 5th and 95th percentile 10-year CBC risks were 22% and 32% for BRCA1 and 13% and 23% for BRCA2 heterozygotes, respectively. Conclusion: The PRS 313 can be used to refine individual CBC risks for BRCA1/2 heterozygotes of European ancestry, however the PRS 313 needs to be considered in the context of a multifactorial risk model to evaluate whether it might influence clinical decision-making.

Original languageEnglish
Pages (from-to)1726-1737
Number of pages12
JournalGenetics in medicine
Volume23
Issue number9
DOIs
Publication statusPublished - 1 Sept 2021

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