The 21-Gene Recurrence Score Assay and Prediction of Chemotherapy Benefit: A Propensity Score-Matched Analysis of the SEER Database

Cost-Effectiveness Analysis of the Oncotype DX Breast Recurrence Score® Test from a US Societal Perspective

Background and Objectives

The 21-gene assay (the Oncotype DX Breast Recurrence Score® test) estimates the 10-year risk of distant recurrence in hormone receptor positive (HR+) and human epidermal growth factor receptor 2 negative (HER2-) early-stage breast cancer to inform adjuvant chemotherapy decisions. The cost-effectiveness of the 21-gene assay compared against standard clinical-pathological risk tools alone for HR+/HER2- early-stage breast cancer was assessed using an economic model informed by evidence from randomized controlled trials.

Materials and Methods

A cost-effectiveness model consisted of a decision-tree to stratify patients according to their Recurrence Score (RS) results and the use of adjuvant chemotherapy, followed by a Markov component to estimate the long-term costs and outcomes of the chosen treatment. Distributions of patients and distant recurrence probabilities were derived from the TAILORx (N0) and RxPONDER (N1) trials. The model was evaluated from a healthcare payer and societal perspective. Endocrine therapy and chemotherapy use were informed using clinical expert opinion to reflect US clinical practice and were combined with Medicare drug costs (2021) to estimate the cost of treatment. Societal costs included lost productivity and patient out-of-pocket costs obtained from literature.

Results

The Oncotype DX test generated more quality-adjusted life-years (QALYs) (N0: 0.25; N1: 0.08) at a lower cost (N0: -$13,395; N1: -$2526) compared to clinical-pathological risk alone from a societal cost perspective. The overall conclusions from the model did not change when considering a payer perspective. The main cost drivers were avoidance of distant recurrence for N0 (-$12,578), and the cost of adjuvant chemotherapy for N1 (-$2133). Lost productivity had a major impact in the societal perspective analysis (N0: -$4607; N1: -$1586).

Conclusion

Adjuvant chemotherapy decisions based on the RS result led to more life year gains and lower healthcare costs (dominant) compared to using clinical-pathological risk factors alone among patients with HR+/HER2- N0 and N1 early-stage breast cancer.

Survival Benefit of Chemotherapy According to 21-Gene Recurrence Score in Young Women with Breast Cancer

BACKGROUND

Initial trials evaluating Oncotype DX, reported as a recurrence score (RS) from 0 to 100, were not powered to evaluate overall survival, and premenopausal women were underrepresented. The purpose of this study was to explore the benefit of chemotherapy according to RS among younger women eligible for oncotype testing.

METHODS

Women aged 40-50, diagnosed with HR-positive, HER2-negative breast cancer between 2010 and 2017 were selected from the National Cancer Database (NCBD). Patients were grouped by age, RS, nodal status, and chemotherapy receipt. Kaplan-Meier curves were used to compare unadjusted overall survival (OS) between the groups, and log-rank tests were used to test for a difference between groups. Cox proportional hazards models were used to examine the association between select factors and OS.

RESULTS

A total of 15,422 patients met inclusion criteria, 45.3% of whom received chemotherapy. Median follow-up time was 66.4 (50.6-86.6) months. Patients who received chemotherapy were more likely to have higher-stage and higher-grade tumors, tumors that were PR-negative, and have higher RS (p < 0.001 for all). RS was prognostic for OS regardless of nodal status. After adjustment, chemotherapy was associated with a significant improvement in OS only in the pN1 RS 31-50 subgroup (p = 0.02).

CONCLUSIONS

RS retains its prognostic value in younger patients with early stage HR-positive, HER2-negative breast cancer. Chemotherapy survival benefit was limited to patients aged 40-50 with pN1 disease and RS of 31-50. Therefore, chemotherapy decision-making should be especially preference-sensitive in women aged 40-50 with intermediate RS, where it may not provide a survival benefit for many women.

The budget impact of utilizing the Oncotype DX Breast Recurrence Score test from a US healthcare payer perspective

BACKGROUND AND OBJECTIVES

The Oncotype DX Breast Recurrence Score test is used to estimate distant recurrence risk of hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) early-stage breast cancer and inform decisions on the use of adjuvant chemotherapy. A model-based budget impact analysis compared the Oncotype DX test in combination with clinical-pathological risk against using clinical-pathological risk alone for HR+/HER2- node-negative (N0) and node-positive (N1; 1-3 axillary lymph nodes) early-stage breast cancer patients.

MATERIALS AND METHODS

Test and medical costs associated with treatment of breast cancer were assessed through a US healthcare payer perspective. Distributions of patients by Recurrence Score result and distant recurrence probabilities with chemo-endocrine and endocrine therapy were derived from the TAILORx (N0) and RxPONDER (N1) trials. Changes in budget impact were evaluated over a 5-year horizon for a 1,000,000-member hypothetical health plan.

RESULTS

With the Oncotype DX test, there was an incremental budget impact of $261,067 (per member per month (PMPM): $0.004), in the N0 population, and $56,143 (PMPM: $0.001) in the N1 population over the 5-year period. The largest budget impact reduction in the N0 population was attributed to reduced breast cancer recurrence costs (incremental: -$633,457, PMPM: -$0.011), while chemotherapy sparing reduced costs in the N1 population (incremental: -$94,884, PMPM: -$0.002).

CONCLUSION

The clinical benefit of using the Oncotype DX test to inform adjuvant chemotherapy decisions has been shown in multiple randomized controlled trials. This analysis demonstrated that while using the Oncotype DX test to inform adjuvant chemotherapy decisions may slightly increase US healthcare costs over an initial 5-year time horizon (driven by a cost increase in the first year with cost savings reflected in remaining 4 years), there is significant scope for cost savings when assessing beyond this period due to avoided downstream costs of distant recurrence and long-term chemotherapy adverse events. PMPM costs also remain low across all populations examined, demonstrating a close-to-neutral budget impact.

Gene expression signatures in older patients with breast cancer: A systematic review

BACKGROUND

Gene expression signatures have emerged to predict prognosis and guide the use of adjuvant therapy in patients with hormone receptor-positive breast cancer. The objective of this systematic review was to evaluate the prognostic and predictive value of commercially available gene expression signatures as a tool in adjuvant treatment decision-making in older patients with breast cancer.

METHODS

PubMed, MEDLINE, Embase, Web of Science, Cochrane Library, and Emcare were reviewed for relevant articles published before December 2021. Eligible studies were randomised trials and cohort studies that externally validated commercially available gene expression signatures in patients aged 65 years and older, including studies that presented subanalyses of this age group. Data extraction and risk of bias assessment was performed independently by two investigators.

RESULTS

Fifteen studies were included. Most studies investigated Oncotype DX, while results from other gene expression signatures were limited. Several studies underlined the prognostic performance of Oncotype DX and Prosigna Risk of Recurrence in older patients. Moreover, Oncotype DX was predictive for older patients with an intermediate-risk recurrence score; chemotherapy could be spared in both lymph node-positive and lymph node-negative disease.

CONCLUSIONS

Prognostic performance has been demonstrated in older patients for several gene expression signatures. However, additional validation in patients with high-risk tumours is needed before gene expression signatures can be implemented in clinical practice as a prediction tool for adjuvant chemotherapy decision-making in the older age group.

Molecular differences between younger versus older ER-positive and HER2-negative breast cancers

The RxPONDER and TAILORx trials demonstrated benefit from adjuvant chemotherapy in patients age ≤ 50 with node-positive breast cancer and Recurrence Score (RS) 0-26, and in node-negative disease with RS 16-25, respectively, but no benefit in older women with the same clinical features. We analyzed transcriptomic and genomic data of ER+/HER2- breast cancers with in silico RS < 26 from TCGA (n = 530), two microarray cohorts (A: n = 865; B: n = 609), the METABRIC (n = 867), and the SCAN-B (n = 1636) datasets. There was no difference in proliferation-related gene expression between age groups. Older patients had higher mutation burden and more frequent ESR1 copy number gain, but lower frequency of GATA3 mutations. Younger patients had higher rate of ESR1 copy number loss. In all datasets, younger patients had significantly lower mRNA expression of ESR1 and ER-associated genes, and higher expression of immune-related genes. The ER- and immune-related gene signatures showed negative correlation and defined three subpopulations in younger women: immune-high/ER-low, immune-intermediate/ER-intermediate, and immune-low/ER-intermediate. We hypothesize that in immune-high cancers, the cytotoxic effect of chemotherapy may drive the benefit, whereas in immune-low/ER-intermediate cancers chemotherapy induced ovarian suppression may play important role.

Secondary Invasive Breast Events among Patients with Hormone-Positive Breast Cancer and High-Risk Oncotype DX Recurrence Scores 26-30 and ≥31

BACKGROUND

The Oncotype DX Recurrence Score (ODx RS) is the most widely adopted genomic assay used to guide treatment for patients with early-stage, hormone-positive (HR+) breast cancer (BC), with higher scores predicting greater risk of recurrence and benefit from chemotherapy. Patients with ODx RS >25 typically recieve adjuvant chemotherapy; however, data regarding efficacy of chemotherapy for reducing recurrence in this population have been mixed.

OBJECTIVES

This study aimed to evaluate outcomes of patients with early-stage HR+ BC with high-risk ODx RS (26-30 and ≥31) in order to assess treatment patterns and outcomes. We hypothesized that the benefit of chemotherapy in these groups may be minimal and that select patients may forgo chemotherapy in favor of more aggressive endocrine therapy and ovarian suppression.

METHODS

We performed a retrospective analysis of 515 patients with early-stage, HR+ BC with high-risk ODx RS 26-30 and ≥31 treated between 2006 and 2018. Patients were stratified by RS: low-risk (≤10), intermediate-risk (11-25), and high-risk (≥26). The Kaplan-Meier method was used to estimate the time to secondary invasive breast events (SIBE) or distributions overall and among different RS groups with the log rank test used to compare distributions between groups.

RESULTS

Rates of chemotherapy administration were 7% among the low-risk group, 18% among the intermediate-risk group, and 83% among high-risk patients with 41 SIBE (8%) reported. When stratified by ODx RS, 5-year rates of SIBE were 4%, 6%, and 16% for low-risk, intermediate-risk, and high-risk RS, respectively. Among the 27 lymph node (LN)-negative patients with ODx RS 26-30, 74% received chemotherapy. The 5-year rate of SIBE was 25% among patients who received chemotherapy and 33% among those who did not (p = 0.5489). Among the 23 LN-negative patients with ODx RS ≥31, 91% of patients received chemotherapy. The 5-year rate of SIBE was 0% both with and without chemotherapy.

CONCLUSIONS

There was no statistically significant difference in SIBE for patients with high-risk ODx RS based on chemotherapy treatment. More aggressive endocrine therapy with ovarian suppression has become an alternative to chemotherapy among patients with intermediate-risk ODx RS (16-25). This approach may be useful among patients with high-risk ODx RS, with additional studies needed in this patient population.

Application of the 21-Gene Recurrence Score in Patients with Early HR-Positive/HER2-Negative Breast Cancer: Chemotherapy and Survival Rate According to Clinical Risk

Simple Summary

It is important to address the influence of 21-gene Recurrence Score (RS) on chemotherapy decision-making stratified by clinical risk in patients with hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative early breast cancer. Our study presented that the application of the 21-gene RS assay significantly reduced the chemotherapy rate in patients with high clinical risk. Meanwhile, there was no significant difference in the chemotherapy rate according to the implementation of the 21-gene RS assay in those with low clinical risk. Furthermore, we observed no difference in prognosis according to the application of 21-gene RS for either clinical risk. These results suggest that the 21-gene RS could be considered more positively in HR+/HER2- patients with high clinical risk to reduce chemotherapy rates without increasing the occurrence of relapse.

Abstract

We assessed the impact of 21-gene Recurrence Score (RS) assay on chemotherapy decision-making according to binary clinical risk stratification in patients with hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative early breast cancer. We included patients with tumors measuring 1–5 cm, N0-1, and HR+/HER2- breast cancer who underwent surgery followed by adjuvant treatment. The clinical risk was determined by a modified version of Adjuvant! Online. We performed propensity score matching (PSM) according to the application of 21-gene RS separately in the low and high clinical risk groups. Before PSM, 342 (39.0%) of 878 patients were classified as having high clinical risk. In the high clinical risk group, 21-gene RS showed a significantly reduced chemotherapy rate of 39.3%, without increasing the recurrence. After PSM, the 21-gene RS application significantly reduced chemotherapy rate by 34.0% in 200 patients with high clinical risk (21-gene RS application, 32.0% vs. no 21-gene RS application, 66.0%, p < 0.001). There was also no significant difference in RFS according to 21-gene RS status in the high clinical risk group (log-rank test, p = 0.467). These results support the usefulness of the 21-gene RS to reduce the chemotherapy rate without adversely affecting prognosis in a high clinical risk group.

Adjuvant chemotherapy and survival outcome in node-negative breast cancer with a 21-gene recurrence score of 26-30

Aim: To investigate the benefit of chemotherapy among early-stage breast cancer patients with 21-gene recurrence scores of 26-30. Methods: We identified 3754 patients in the Surveillance, Epidemiology, and End Results database. Results: 57.6% of the patients received adjuvant chemotherapy. Patients with higher tumor grade, larger tumors and younger age were more likely to receive chemotherapy. The receipt of chemotherapy was independently associated with better breast cancer-specific survival than in patients without chemotherapy before (p = 0.016) and after (p = 0.043) propensity score matching. The sensitivity analyses showed that survival gain was pronounced in patients with poorly differentiated or undifferentiated disease. Conclusions: Adjuvant chemotherapy improves the outcome for early-stage breast cancer with 21-gene recurrence score of 26-30, especially for patients with high-grade tumors.