Disparities in Access to Multigene Testing in Early-Stage, HR-positive, HER2-negative, Lymph Node-negative Breast Cancer

Background Multigene testing (MGT) has refined breast cancer treatment. We examined real-world access to MGT for early-stage (I-II), HR-positive, HER2-negative, node-negative breast cancer and identified factors related to disparities. Materials and Methods This retrospective analysis used the National Cancer Database (2007-2017). Socio-demographic and clinical-pathologic factors of interest were included in a multivariable logistic regression to examine associations with MGT use. Multiple imputation was used to find missing data. Results A total of N=107,642 patients were eligible, of which 65,066 (60%) underwent MGT. The odds of undergoing MGT were lower among Black patients compared to White (OR 0.83, 95% CI 0.79–0.87, p<0.001), Hispanic compared to non-Hispanic (OR 0.91, 95% CI 0.86–0.97, p=0.004), uninsured compared to privately insured (OR 0.73,95% CI 0.64–0.83, p<0.001), and those in the West South-Central compared to New England region (OR 0.76,95% CI 0.70–0.82, p<0.001). Increased odds were observed among those treated at an Integrated Network Cancer Program (OR 1.12,95%CI 1.05-1.19, p<0.001), higher education level (OR 1.12, 95%CI 1.06–1.19, p<0.001), and a household income between $50,354 to $63,332 (OR 1.08, 95%CI 1.02–1.14, p=0.006). Those with access to MGT had higher odds of receiving adjuvant chemotherapy (OR 1.89,95% CI 1.80-1.99, p<0.001) and hormonal therapy (OR 3.17, 95% CI 3.02-3.32, p<0.001) compared to those without access to MGT after adjusting for other factors of interest. Conclusions This study highlights gaps in access to MGT in breast cancer. Ensuring equitable access to diagnostic and prognostic precision tools could positively impact the odds of receiving appropriate adjuvant therapy and improve patient outcomes. Micro abstract This study examined real-world access to multigene testing (MGT) for early-stage, HR-positive, HER2-negative, node-negative breast cancer using data from the National Cancer Database (2007-2017). We found that racial minorities, the uninsured, and patients treated at community cancer programs had lower odds of receiving MGT. Higher education, higher household income, and treatment at integrated cancer centers were associated with increased MGT access. Patients with access to MGT had higher odds of receiving adjuvant chemotherapy and hormonal therapy. Addressing disparities in access to MGT could improve personalized treatment and outcomes for patients diagnosed with breast cancer.