Cross-sectional study of genetic testing uptake among patients with newly diagnosed breast cancer

Offering universal genetic testing (GT) to females diagnosed with breast cancer identifies pathogenic variants in over 1 in 20 patients, and results of GT inform systemic therapy decisions in one-third of cases. Recent recommendations included offering germline GT to all patients with breast cancer diagnosed before age 66 years. However, uptake of GT lags behind recommendations. A cross-sectional study at a single center in Montreal (Canada) explored patient characteristics associated with uptake of GT for breast cancer susceptibility genes. A total of 805 adult women with a first diagnosis of invasive breast cancer were offered free GT. Overall 67 patients (8.3%) declined consultation for GT, 9 (1.1%) declined GT after counseling, and 729 (90.6%) underwent GT. Women who choose GT were younger at diagnosisn (median age 53 versus 64 years; p<0.001). Compared with those who refused, those accepting GT more often presented with higher grade disease (31.4% versus 17.8%; p=0.03) or TNBC (15.4% versus 8.2%; p=0.049) and were less likely to have stage I disease (47.3% versus 60.3%; p=0.01). 41.1% of patiens who declined had no family history of cancer, compared with 21.5% of those who accepted testing (p=0.003). On multivariable logistic regression including covariates significant on univariate analysis, age group, family history, and stage remained significantly associated with GT uptake.