biostudies-literatureDurham DDNational Cancer InstituteNCI NIH HHSDivision of Cancer Prevention, National Cancer InstituteNational Institutes of HealthPatient-Centered Outcomes Research Institute4232-4240https://www.ebi.ac.uk/biostudies/studies/S-EPMC9712500biostudies-literatureUnknown128(24)<h4>Background</h4>Women with a first-degree family history of breast cancer are often advised to begin screening when they are 10 years younger than the age at which their relative was diagnosed. Evidence is lacking to determine how much earlier they should begin.<h4>Methods</h4>Using Breast Cancer Surveillance Consortium data on screening mammograms from 1996 to 2016, the authors constructed a cohort of 306,147 women 30-59 years of age with information on first-degree family history of breast cancer and relative's age at diagnosis. The authors compared cumulative 5-year breast cancer incidence among women with and without a first-degree family history of breast by relative's age at diagnosis and by screening age.<h4>Results</h4>Among 306,147 women included in the study, approximately 11%CancerBreast cancer incidence among women with a family history of breast cancer by relative's age at diagnosis.PMC9712500P01CA154292PCS‐1504‐30370U54CA163303U54 CA163303P01 CA154292Durham DDSmith RAKhan CPAbraham LAKerlikowske KMiglioretti DLRoberts MCfalseBreast cancer incidence among women with a family history of breast cancer by relative's age at diagnosis.<h4>Background</h4>Women with a first-degree family history of breast cancer are often advised to begin screening when they are 10 years younger than the age at which their relative was diagnosed. Evidence is lacking to determine how much earlier they should begin.<h4>Methods</h4>Using Breast Cancer Surveillance Consortium data on screening mammograms from 1996 to 2016, the authors constructed a cohort of 306,147 women 30-59 years of age with information on first-degree family history of breast cancer and relative's age at diagnosis. The authors compared cumulative 5-year breast cancer incidence among women with and without a first-degree family history of breast by relative's age at diagnosis and by screening age.<h4>Results</h4>Among 306,147 women included in the study, approximately 11%2022-01-01T00:00:00Z2022 Dec2025-04-05T10:55:31.347Z2025-04-05T10:55:31.347ZS-EPMC97125003626203510.1002/cncr.34365