Sociodemographic and clinical characteristics of women < 50 years and impact on adjuvant chemotherapy decisions across OncotypeDX RS or unknown OncotypeDX categories. A National Cancer Database (NCDB) analysis.

Abstract

e12547 Background: OncotypeDX recurrence score (RS) provides prognostic and predictive information to guide adjuvant treatment decisions in non-metastatic HR+/HER2-negative breast cancer (BC). However, premenopausal patients (pts) have not been well characterized in the existing literature, particularly with respect to sociodemographic factors. Considering these gaps, we evaluated the impact of sociodemographic and clinical characteristics on chemotherapy (CT) recommendations across RS categories or unknown RS. Methods: This retrospective analysis included NCDB data from 2018-2022 for pts < 50 years old (surrogate for premenoapusal status) with clinically node negative stage I-III HR+/HER2-negative BC who underwent upfront surgery. OncotypeDX RS was coded as ≤15, 16-20, 21-25, ≥26 or unknown. Multivariable binary logistic regressions assessed the associations between sociodemographic as well as clinical characteristics and receipt of adjuvant CT stratified by each RS category. Results: 19,438 pts were included: 7340 had unknown RS, 6040 with low RS (≤15), intermediate RS, including 2908 (RS 16-20) and 1496 (RS 21-25); and 1654 with high RS (≥26). Patients with high (vs low) RS were younger (median age 43 vs 45 years). Racial differences were evident, with more Black pts in the high vs low RS group (15.5% vs 8.2%). Patients with high (vs low) RS had poorly differentiated tumors (42.8% vs 3.5%), and PR negative and low (30% vs 1.9%). Fewer pts had private insurance in the high vs low RS (83.9% vs 84.5%). More patients received CT in the high (vs low) RS group (88.8% vs 4.4%). CT receipt was 16.4% in RS 16-20, and 54.0% in pts with RS 21-25. In the unknown RS, 40.9% of pts received CT. Among the unknown RS cohort, characteristics associated with lower odds of CT receipt were: older age, ductal (vs lobular) histology, moderate/high PR expression (vs none/low), and pts with sentinel LN biopsy (vs axillary LN dissection). In contrast, the following characteristics had higher odds of CT receipt: low/moderate ER (vs high), pT3/T4 (vs pT1/T2) and pN1+ (vs pN0), and moderately or poorly (vs well) differentiated tumors. In pts with low and intermediate (0-25) RS, pts had higher odds of CT receipt if pT3/T4, pN1+ and poorly/moderately differentiated tumors. Conclusions: Over a third of women < 50 years had an unknown OncotypeDX RS. Significant sociodemographic and clinical differences were observed across RS categories, most notably between high and low RS. Patients with a higher RS are associated with distinct sociodemographic characteristics: younger age, Black race and lower proportion had private insurance. Overall, in addition to age, tumor characteristics (size, nodal status, tumor grade) appear to have the strongest association with CT receipt, regardless of RS.