Frequency of germline pathogenic variants in breast cancer predisposing genes in a national cohort of young women with breast cancer
摘要
The objective of the study was to evaluate the prevalence of pathogenic variants in 18 cancer predisposition genes in a national cohort of women with breast cancer diagnosed at age 40 or younger.
MethodsWomen with breast cancer at age ≤40 years were recruited from 33 Canadian centres at diagnosis. Germline genetic testing was performed for 18 genes (ATM, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, PALB2, PTEN, STK11, RAD51D, RAD51C, EPCAM, MLH1, MSH2, MSH6, and PMS2). Prevalence of pathogenic variants (PVs) was estimated by age, family history and clinical characteristics.
ResultsIn 805 women, 153 PVs were found (positivity rate 18.6%). Most PVs (63%) were found in BRCA1 (50) or BRCA2 (46). Other PVs were in CHEK2 (24), ATM (13), PALB2 (10), TP53 (5), BRIP1 (1), BARD1 (1), CDH1 (1) and PTEN (1). Higher PV frequencies were found in women with tumours with lobular histology (29.2%), triple negative cancers (27.5%), and bilateral breast cancers (35.7%).
ConclusionsOverall, 18.6% of women with young breast cancer had PVs in 18 genes tested, including 6.8% in a gene other than BRCA1 or BRCA2. Study results suggest that genetic testing should be offered to all women diagnosed breast cancer at the age of 40 or younger.