Use of 21-gene recurrence score assay to individualize adjuvant chemotherapy recommendations in ER+/HER2− node positive breast cancer—A National Cancer Database study

Abstract

The 21-gene Recurrence Score (RS) assay is prognostic and predictive of adjuvant chemotherapy benefit in node positive (N+) breast cancer (BC). We sought to evaluate use patterns of RS assay in N+, ER+/HER2− BC and the impact of RS on recommendations for adjuvant chemotherapy. Patients with T1-T4c,N1mi-N3, ER+/HER2− BC diagnosed 2010–2013 in the National Cancer Database were analyzed. Multivariable logistic regression assessed factors influencing RS testing and chemotherapy recommendations based on RS. Among 72,897 patients, RS was obtained in 20.6%, increasing from 15.0% in 2010 to 24.5% in 2013 (p < 0.001). RS testing was most common in N1mi (43.7%) followed by N1 (22.1%) and rare in N2/N3 (3.3%). Of the 12,536 with quantitative RS results, 61.1% were low RS, 32.3% intermediate RS and 6.6% high RS. Chemotherapy was recommended less frequently in patients with RS testing (50.4%) vs. those not tested (81.0%, p < 0.001). In N1mi/N1 patients, chemotherapy recommendation varied by RS; however, in N2/N3 patients, chemotherapy was recommended in the majority (70.9–87.5%) regardless of RS. Most patients (>85%) with RS ≥ 26 were recommended chemotherapy regardless of nodal stage. For patients with RS < 26, chemotherapy recommendations increased with higher N and T stage, grade, and younger age (p < 0.001). Histology was not associated with chemotherapy recommendation in any RS subset. The RS assay is frequently and increasingly being used for decision making in node positive ER+/HER2− breast cancer patients and its use is associated with lower rates of adjuvant chemotherapy.

Male breast cancer in the United States: Treatment patterns and prognostic factors in the 21st century

“…The results from the current study and others [41][42][43] have suggested that the distribution of Oncotype DX scores is similar between men and women and that Oncotype DX already is increasingly being used in the management of MBC. We are awaiting long-term outcomes data to fully understand the implications of this practice.…”

“…Although prospective evidence to support their use is lacking, gene expression profiles such as the Oncotype DX recurrence score may be helpful in patients with MBC to decide whether to administer chemotherapy. The results from the current study and others have suggested that the distribution of Oncotype DX scores is similar between men and women and that Oncotype DX already is increasingly being used in the management of MBC. We are awaiting long‐term outcomes data to fully understand the implications of this practice.…”

The 21-Gene Recurrence Score in Male Breast Cancer

“…However, in a large comparative series of >3,500 age- and stage-matched male and female patients, only 27% of male breast cancer patients received adjuvant chemotherapy compared to 41% of female breast cancer patients [28]. In addition to successfully using the RS risk categories for adjuvant treatment selection in early-stage, ER-positive, HER2-negative female breast cancer patients [11,18], the RS assay is increasingly being incorporated in decision making for node-positive patients [29–32]. Given the lower incidence of chemotherapy despite the advanced clinical presentation of male breast cancer, the RS assay may allow a better selection of adjuvant systemic therapy in male patients.…”

Tumor Biology and Response to Chemotherapy Impact Breast Cancer-specific Survival in Node-positive Breast Cancer Patients Treated With Neoadjuvant Chemotherapy

“…[39] In one retrospective study, use of the 21-gene recurrence score in node-positive disease was shown to decrease the rate of recommendation for adjuvant chemotherapy from 81% to 50%. [40] The West German Plan B prospective trial showed excellent 3-year survival of patients with a recurrence score ≤11 treated without chemotherapy and included patients with node-positive disease. [41]…”