Effect of multiplicity, laterality, and age at onset of breast cancer on familial risk of breast cancer: a nationwide prospective cohort study
The objective of this nationwide prospective cohort study is to find out the risk of breast cancer (BC) in relatives of patients with multiple BCs by laterality and age at diagnosis of first BC. Having family history of single (HR 1.8; 95 % CI 1.8-1.9) or multiple (HR 2.7; 95 % CI 2.6-2.9) BC was associated with higher risk of BC. Those with an FDR with contralateral BC at any age had the highest
