RS Results Research Articles

Impact of HIV infection on cervical intraepithelial neoplasia detection in pregnant and non-pregnant women in Germany: a cross-sectional study.

Women living with HIV (WLWH) are frequently affected by cervical dysplasia caused by Human Papillomavirus (HPV) and invasive cervical cancer (CxCa). CxCa screening programs can include colposcopy, cytology, and HPV testing. These methods, however, have limitations in effectively stratifying cervical dysplasia. This study aimed to evaluate the applicability of an innovative mRNA-based multiplexed expression-quantifying assay in the detection and assessment of cervical dysplasia in WLWH. The QuantiGene-Molecular-Profiling-Histology Assay (QG-MPH) was used to detect and quantify HPV oncogene and cellular biomarker mRNA expression. These results were included in the Risk Score (QG-MPH RS) calculations that inform about the presence and severity of dysplasia. QG-MPH RS results were compared to the highly sensitive Multiplexed Papillomavirus Genotyping (MPG) Assay and clinical results obtained by cytology, colposcopy and histology. For a standardized nomenclature of clinical results, the clinical ASSIST Score was used. Of 241 WLWH, including 96 pregnant women, a concordance between the QG-MPH RS and the ASSIST Score was found to 36.3% (49/135) in non-pregnant WLWH and 67.1% (57/85) in pregnant WLWH. The QG-MPH method demonstrated high specificity for detecting high-risk HPV (HR-HPV) genotypes and high-grade cervical dysplasia, achieving 89.6% and 82.4%, respectively, including pregnant and non-pregnant WLWH. The QG-MPH assay shows potential for improving the detection and management of HPV-related cervical dysplasia in WLWH, including pregnant women. Its high specificity, however, is tempered by its tendency to overestimate dysplasia severity in certain cases, indicating that further research is needed to refine its use as a reliable diagnostic tool for this high-risk population.

Irish national real-world analysis of the clinical and economic impact of 21-gene oncotype DX® testing in early-stage, 1-3 lymph node-positive, oestrogen receptor-positive, HER2-negative, breast cancer.

The treatment landscape of Oestrogen receptor-positive (ER-positive) breast cancer is evolving, with declining chemotherapy use as a result of Oncotype DX Breast Recurrence Score® testing. Results from the SWOG S1007 RxPONDER trial suggest that adjuvant chemotherapy may benefit some premenopausal women with ER-positive, HER2-negative disease with 1-3 positive lymph nodes (N1), and a Recurrence Score® (RS) of ≤ 25. Postmenopausal women with similar characteristics did not benefit from adjuvant chemotherapy. We examine the clinical and economic impact of Oncotype DX® testing on treatment decisions in patients with N1 disease in Ireland using real world data. From March 2011 to October 2022, a retrospective, cross-sectional observational study was performed of patients with ER-positive, HER2-negative N1 breast cancer, who had Oncotype DX testing across 5 of Ireland's largest cancer centres. Patients were classified into low risk (RS 0-13), intermediate risk (RS 14-25) and high risk (RS > 25). Data were collected via electronic patient records. Information regarding costing was provided primarily by pre-published sources. A total of 828 N1 patients were included in this study. Post Oncotype DX testing, 480 patients (58%) were spared chemotherapy. Of the patients who had a change in chemotherapy recommendation based on Oncotype DX testing, 271 (56%), 205 (43%), 4 (1%) had a RS result of 0-13, 14-25 and > 25 respectively. Use of Oncotype DX testing was associated with a 58% reduction in chemotherapy administration overall. This resulted in estimated savings of over €6 million in treatment costs. Deducting the assay cost, estimated net savings of over €3.3 million were achieved. Changes in the ordering demographics of Oncotype DX tests were identified after RxPONDER data were presented, with increased testing in women ≥ 50years and a reduction in proportion of tests ordered for women < 50years. Between 2011 and 2022, assay use resulted in a 58% reduction in chemotherapy administration and net savings of over €3.3 million.

The REMAR (Rhein-Main-Registry) real-world study: prospective evaluation of the 21-gene breast recurrence score® assay in addition to Ki-67 for adjuvant treatment decisions in early-stage breast cancer

PurposeKi-67 is recommended by international/national guidelines for risk stratification in early breast cancer (EBC), particularly for defining “intermediate risk,” despite inter-laboratory/inter-observer variability and cutoff uncertainty. We investigated Ki-67 (> 10%– < 40%, determined locally) as a prognostic marker for intermediate/high risk in EBC, pN0-1 patients.MethodsThis prospective, non-interventional, real-world study included females ≥ 18 years, with pN0/pN1mi/pN1, HR+ , HER2-negative EBC, and locally determined Ki-67 ranging 10%–40%. The primary outcome was changes in treatment recommendations after disclosing the Oncotype DX Breast Recurrence Score®(RS) assay result.ResultsThe analysis included 567 patients (median age, 57 [range, 29–83] years; 70%/1%/29%/ with pN0/pN1mi/pN1 disease; 81% and 19% with RS results 0–25 and 26–100, respectively). The correlations between local and central Ki-67, local Ki-67, and the RS, and central Ki-67 and the RS results were weak (r = 0.35, r = 0.3, and r = 0.46, respectively), and discrepancies were noted in both directions (e.g., local Ki-67 was lower or higher than central Ki-67). After disclosing the RS, treatment recommendations changed for 190 patients (34%). Changes were observed in pN0 and pN1mi/pN1 patients and in patients with centrally determined Ki-67 ≤ 10% and > 10%. Treatment changes were aligned with RS results (adding chemotherapy for patients with higher RS results, omitting it for lower RS results), and their net result was 8% reduction in adjuvant chemotherapy use (from 32% pre-RS results to 24% post-RS results).ConclusionThe Oncotype DX® assay is a tool for individualizing treatments that adds to classic treatment decision factors. The RS result and Ki-67 are not interchangeable, and Ki-67, as well as nodal status, should not be used as gatekeepers for testing eligibility, to avoid under and overtreatment.

Abstract PO4-08-09: Concordance analysis of paired breast cancer core needle biopsies and surgical excision samples using the Oncotype DX Breast Recurrence Score® assay

Abstract INTRODUCTION: The Oncotype DX Breast Recurrence Score® (RS) assay is validated to predict risk of distant recurrence at 10 years and the benefit of adjuvant chemotherapy in patients with estrogen receptor (ER)+, HER2- early breast cancer who receive 5 years of endocrine therapy. The feasibility of Oncotype DX® testing with diagnostic core needle biopsies (CNB) was demonstrated through analysis of a large commercial laboratory experience. The neoadjuvant ADAPT study showed the clinical utility of deriving the Recurrence Score® (RS) result from CNB as well. However, data are limited on concordance of RS results from paired CNB and surgical samples. Our primary objective was to determine the degree of concordance of RS results between paired tissue samples from the same primary breast tumor of patients with early stage, ER+, HER2- invasive breast cancer who had a CNB and subsequent surgical excision (SE; lumpectomy or mastectomy) without intervening systemic therapy. METHODS: Patients with a commercial RS result on either CNB or subsequent SE were identified through medical record and clinical database review. A pathologist reviewed archival tissue samples to confirm eligibility and selected the other paired CNB or SE block most representative of the tumor tissue for subsequent study Oncotype DX testing. Descriptive statistics were used to summarize patient and tumor characteristics. Wilcoxon signed rank, McNemar’s and Cochran-Mantel-Haenszel tests were used to compare RS between SE and CNB paired samples. Cohen’s Kappa and 95% confidence intervals (CIs) were used to compare the agreement of categorical RS (0-25 and 26-100) result between SE and CNB paired samples. Lin’s concordance correlation and 95% CIs were used to compare agreement of continuous RS between paired samples. RESULTS: A total of 134 patients were identified with paired CNB and SE samples with a median time of 34 (range 5-103) days between collections. Of the 134 patients, a commercial RS result was available for 25 (18.7%) with CNB and 109 (81.3%) with SE. A study RS result was then generated on the other paired sample. Median age was 62 years (range 33-99; 23 patients [17%] were age ≤50 vs. 111 [83%] age &amp;gt;50). Cases were predominantly node negative (107/134 node negative vs. 26/134 node positive; 1/134 unknown) invasive ductal carcinomas (104/134 ductal vs. 18/134 classic lobular vs. 12/134 other). Mean RS results were 15.6 (range 0-56) and 16.6 (range 0-59) for CNB and SE, respectively (p = 0.003), with no statistically significant differences in RS category defined as low vs. high risk (119/134 CNB vs. 114/134 SE for RS 0-25 and 15/134 CNB vs 20/134 SE for RS 26-100; p = 0.13) or low vs. intermediate vs. high risk (85/134 CNB vs. 78/134 SE for RS 0-17 and 43/134 CNB vs. 48/134 SE for RS 18-30 and 6/134 CNB vs. 8/134 SE for RS 31-100; p = 0.19). No differences were observed based on age relative to 50 years or nodal status (data not shown). Cohen’s Kappa statistic k = 0.64 (95% CI, 0.44-0.83) supports substantial agreement between the CNB and SE samples. Lin’s concordance correlation coefficient (CCC) demonstrates similar agreement for the continuous RS result between paired samples (CCC = 0.86 [0.80-0.90]). Overall percent agreement was 91.8% (87.1-96.4%). CONCLUSIONS: Studies evaluating the level of concordance of ER, progesterone receptor, and HER2 biomarker status between CNB and SE samples have found high concordance rates, albeit varied. We now provide data demonstrating high concordance of RS results between CNB and SE specimens obtained from the same breast primary tumor without intervening systemic therapy. This supports use of either biopsy source for testing with a genomic predictor to identify those patients who will most likely benefit from chemotherapy and which patients may be spared. Citation Format: Aziza Nassar, Jodi Carter, Paige Innis, Satish Seerapu, Christy Russell, Helena Hanna, Abigail Lochala, Minetta Liu. Concordance analysis of paired breast cancer core needle biopsies and surgical excision samples using the Oncotype DX Breast Recurrence Score® assay [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-08-09.

Abstract PO1-02-02: Update of RSClin with extended TAILORx follow-up and development and validation of a new tool for risk of late distant recurrence

Abstract Background: RSClin® (Sparano et al J Clin Oncol 2020, PMID 33306425) is an educational tool that estimates the 10-year risk of distant recurrence (DR) and the absolute benefit of chemotherapy in HR-positive, HER2-negative, node-negative early breast cancer. The RSClin tool integrates the Recurrence Score® (RS) result with the clinical-pathological features tumor grade, tumor size and patient age using patient-specific meta-analysis (PSMA) applied to the NSABP B-14, TAILORx and NSABP B-20 studies. Approximately 3 years of additional follow-up data have accumulated in the TAILORx study since the RSClin tool was developed, including 50% more DR events in the RS 11-25 group (375 vs. 250), and 46% more DR events in the overall population (561 vs. 384). Methods: The RSClin tool estimates were updated to include the extended follow-up data from TAILORx. As before, the PSMA included 10,004 women with hormone-receptor positive, HER2-negative, node-negative breast cancer from the NSABP B-14 (n=577) trial receiving endocrine therapy (ET) alone and the TAILORx trial receiving ET alone (n=4854) or chemotherapy (CT) plus ET (n=4573). The baseline risk estimate used TAILORx event rates with ET alone. Since there was evidence of differing hazard ratios in years 0-5 versus 5+, models using time-varying effects were used. A patient-specific estimator of absolute CT benefit was computed by combining a PSMA estimate of the individualized relative CT effect from the TAILORx and NSABP B-20 (n=550 HER2-negative) trials with risk estimates for ET alone. Similar methods were used to develop and validate a new tool for assessing the risk of late DR (from year 5 to 10) in patients who survive DR-free for 5 years on ET alone after surgery. External validation of DR risk estimation was performed in an independent cohort of 1098 women enrolled in the Clalit Health Service registry. Results: With the updated data, the model integrating RS result with clinical-pathological features was more informative for DR risk than either RS result alone or the clinical-pathological features alone, both for 10-year DR risk and for late DR risk (likelihood ratio tests, each p≤.001). The updated 10-year RSClin risk estimates are similar to the existing RSClin tool risk estimates with slightly lower risk estimates for very high RS results and more precise estimates for mid-range RS results. The updated chemotherapy effect estimates are slightly lower than for the existing RSClin. The updated RSClin tool 10-year risk estimates were strongly associated with DR risk in the independent Clalit registry (Cox regression p&amp;lt; .001) and closely approximated the observed DR risk (Lin concordance 0.87). The new tool’s late DR risk estimates beyond 5 years were strongly associated with late DR risk in the Clalit registry (Cox regression p=.002) and closely approximated the observed late DR risk (Lin concordance 0.92). Conclusions: The RSClin tool 10-year DR risk estimates have been updated to incorporate extended follow-up data from the TAILORx study. A new tool for assessing late DR risk has been developed and validated that provides more prognostic information than either clinical-pathological features or genomic risk used individually. Citation Format: Joseph Sparano, Michael Crager, Robert Gray, Gong Tang, Jess Hoag, Frederick Baehner, Charles Geyer, Steven Shak, Norman Wolmark, Salomon Stemmer. Update of RSClin with extended TAILORx follow-up and development and validation of a new tool for risk of late distant recurrence [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-02-02.

Abstract PO5-02-04: Irish National Analysis of the Clinical and Economic impact of 21-gene Oncotype DX® testing in Early-Stage, 1-3 lymph node positive, Hormone Receptor positive (HR+), HER2-Negative (HER2-), Breast Cancer (BC)

Abstract PO5-02-04: Irish National Analysis of the Clinical and Economic impact of 21-gene Oncotype DX® testing in Early-Stage, 1-3 lymph node positive, Hormone Receptor positive (HR+), HER2-Negative (HER2-), Breast Cancer (BC)

Xpert-Ultra Assay in Stool and Urine Samples to Improve Tuberculosis Diagnosis in Children: The Médecins Sans Frontières Experience in Guinea-Bissau and South Sudan.

More than half of childhood tuberculosis cases remain undiagnosed yearly. The World Health Organization recommends the Xpert-Ultra assay as a first pediatric diagnosis test, but microbiological confirmation remains low. We aimed to determine the diagnostic performance of Xpert-Ultra with stool and urine samples in presumptive pediatric tuberculosis cases in 2 high-tuberculosis-burden settings. This Médecins Sans Frontières cross-sectional multicentric study took place at Simão Mendes Hospital, Guinea-Bissau (July 2019 to April 2020) and in Malakal Hospital, South Sudan (April 2021 to June 2023). Children aged 6 months to 15 years with presumptive tuberculosis underwent clinical and laboratory assessment, with 1 respiratory and/or extrapulmonary sample (reference standard [RS]), 1 stool, and 1 urine specimen analyzed with Xpert-Ultra. A total of 563 children were enrolled in the study, 133 from Bissau and 400 from Malakal; 30 were excluded. Confirmation of tuberculosis was achieved in 75 (14.1%), while 248 (46.5%) had unconfirmed tuberculosis. Of 553 with an RS specimen, the overall diagnostic yield was 12.4% (66 of 533). A total of 493 stool and 524 urine samples were used to evaluate the performance of Xpert-Ultra with these samples. Compared with the RS, the sensitivity and specificity of Xpert-Ultra were 62.5% (95% confidence interval, 49.4%-74%) and 98.3% (96.7%-99.2%), respectively, with stool samples, and 13.9% (7.5%-24.3%) and 99.4% (98.1%-99.8%) with urine samples. Nine patients were positive with stool and/or urine samples but negative with the RS. Xpert-Ultra in stool samples showed moderate to high sensitivity and high specificity compared with the RS and an added diagnostic yield when RS results were negative. Xpert-Ultra in stool samples was useful in extrapulmonary cases. Xpert-Ultra in urine samples showed low test performance. NCT06239337.

Defining the Biology of Estrogen Receptor-Low-Positive Breast Cancer.

We sought to better define estrogen receptor-low-positive (ER-low+) breast cancer biology and determine the utility of the Oncotype DXBreast Recurrence Score® (RS) assay in this population. Patients with information regarding percentage ER positivity and PAM50 subtype were identified in The Cancer Genome Atlas (TCGA) and subtype distribution was determined. Next, patients with ER-low+ (ER 1-10%), HER2- breast cancer undergoing upfront surgery with known RS result were identified in the National Cancer Database (NCDB) and our institutional Dana-Farber Brigham Cancer Center (DF/BCC) database; RS distribution was examined. Finally, patients with ER-low+, HER2- breast cancer treated at DF/BCC from 2011 to 2020 without prior RS results and in whom tissue was available to perform the assay were identified. RS results, treatment, recurrence and breast cancer-specific survival (BCSS) were determined. Of 1033 patients in TCGA, ER percentage and PAM50 subtype were available for 342 (33.1%) patients. Forty-six (13.5%) had ER-low+/HER2- tumors, among whom 82.6% were basal and 4.3% were luminal A. Among 3423 patients with ER-low+/HER2- disease in the NCDB, RS results were available for 689 (20.1%) patients; 67% had an RS ≥26. In our institutional database, only two patients with ER-low+/HER2- disease and an RS were identified, both with RS ≥26. Among 37 patients in our institutional cohort without prior RS, 35 (97.4%) had an RS ≥26, determined with testing. After a median follow-up of 40 months (range 3-106), three patients, all treated with chemotherapy, recurred. Three-year BCSS was 97.0% (95% confidence interval 96.9-97.1%). Most ER-low+/HER2- breast cancers are basal-like, with RS ≥26 suggesting these tumors are similar to triple-negative disease.

Assessing forecasting performance of daily reference evapotranspiration: A comparative analysis of updated temperature penman-monteith and penman-monteith forecast models

Accurate forecast of reference evapotranspiration (ET0) is essential for effective water resource management and efficient irrigation scheduling. The Penman-Monteith model (PM) recommended by FAO56 is widely used as the standard method for ET0 forecasting, but PM model application is often limited by the absence of forecasted meteorological variables, especially solar radiation (Rs). Previous studies have proposed two types of models based on temperature and sunshine duration to estimate Rs. However, there is currently a lack of comprehensive comparative analysis research to evaluate the performance and applicability of these two types of models combined with weather forecast data for ET0 forecasting using the PM model. To address this issue, we selected China as the research area, which has complex climate zones and an uneven distribution of water resources. The forecasting results of Rs from temperature-based models (M1–M8) and a sunshine duration-based model (M9) are input independently into the PM model for ET0 forecasting. The updated PM model is named PMTM1–PMTM8 and PMF, respectively. We conducted a comprehensive and analytical assessment of the updated PMTM1–PMTM8 model, the PMF model and the Hargreaves-Samani (HS) model in different climate zones of China. The results showed that the accuracy of the M1–M8 and the M9 for forecasting Rs decreased as the forecasting period increased. The accuracy of the M9 was higher than that of M1–M8 in the overall accuracy in the subtropical monsoon climate (SMZ). Both the updated PMTM1–PMTM8 and PMF models were utilized to evaluate the ET0 forecasting performance in all five zones. The PMTM3 model exhibited the highest accuracy, with RMSE and MAE ranges of 0.671–1.572 mm d−1 and 0.532–1.365 mm d−1, respectively. In contrast, the PMF model displayed RMSE and MAE ranges of 0.690–1.590 mm d−1 and 0.641–1.437 mm d−1, respectively. Compared to the PMF model, the updated PMTM1–PMTM5 model showed higher accuracy in forecasting ET0 in the plateau mountain climate, temperate continental climate, temperate monsoon climate, and tropical monsoon climatic zones, but was slightly less accurate in the SMZ. Moreover, both models outperformed the Hargreaves-Samani (HS) model in terms of ET0 forecasting accuracy. Specifically, the updated PMTM1–PMTM5 model demonstrated improved accuracy compared to the temperature-based model HS model across various climate zones, with reductions in RMSE and MAE ranging from 0.117 mm d−1 to 0.616 mm d−1and 0.012 mm d−1 to 0.450 mm d−1, respectively. Overall, the updated PMTM3 model was better than the PMF and thus this model was recommended for daily ET0 forecasting for the near-future at all climate regions across China.

Association between 21-gene-assay and detection of disseminated tumor cells in patients with early breast cancer: results from the IRMA trial

PurposeDisseminated tumor cells (DTCs) in the bone marrow (BM) are known to be of prognostic value for patients with early breast cancer (EBC). In addition to histopathological features, multigene expression assays, such as the commercially available 21-gene Breast Recurrence Score® assay, have been validated for evaluating prognosis and making decisions concerning adjuvant treatment in EBC. In a previous retrospective study from our group, the 21-gene assay was shown to be associated with DTC-detection. A secondary endpoint of the prospective IRMA trial was to evaluate the association between Recurrence Score® (RS) result and tumor cell dissemination in patients with EBC.MethodsDTC-status and RS result were assessed in patients with ER-positive/HER2-negative EBC with 0–3 pathologic lymph nodes who underwent primary surgical treatment at the Department for Women’s Health of Tuebingen University, Germany.ResultsPatients with a high RS result (≥ 26) were more frequently DTC-positive (22.6%) than patients with a low RS result (8.6%, p = 0.034). The odds for DTC-positivity increased with rising RS values (p = 0.047).ConclusionWe therefore confirm that a high genomic risk is associated with tumor cell dissemination into the BM. Further trials are needed to investigate whether therapeutic decisions could be further individualized by combining DTC-status and prognostic gene signature testing.

Abstract P5-03-15: Application of 21-gene Breast Recurrence Score® assay to evaluate prognosis and benefit of adjuvant chemotherapy in BRCA1 and BRCA2 pathogenic variant carriers with early stage, estrogen receptor positive breast cancer

Abstract Background: Minimal data exists for the utilization of the Oncotype Dx® assay specifically in breast cancers associated with BRCA1/2 pathogenic variants (PVs). It is unknown whether estrogen receptor positive (ER+) breast cancer associated with an inherited BRCA1 or BRCA2 (BRCA1/2) PV is more aggressive than disease seen in patients who do not carry an inherited PV, and whether there are differences between BRCA1 and BRCA2. In prostate cancer patients with inherited cancer predisposition due to a BRCA2 PV, more aggressive cancers are observed, which influences first-line treatment. Limited data exists for the optimal management of early stage ER+ breast cancer in BRCA1/2 PV carriers. Comparing Recurrence Score® (RS) results in ER+ breast cancer patients with an inherited BRCA1/2 PV (cases) versus matched patients who test negative for a PV in BRCA1/2 (controls) may inform whether biologically more aggressive breast cancer is seen in BRCA1/2 carriers and optimal treatment approaches. Methods: A retrospective case control study was performed to compare RS results in women with breast cancer with an inherited BRCA1/2 PV versus patients who tested negative for an inherited BRCA1/2 PV. Female breast cancer patients seen between 2005-2020 at NorthShore University Health System with ER+Her2- early stage invasive breast cancer with 0-3 lymph nodes who completed genetic testing for BRCA1/2 were eligible for enrollment. BRCA1/2 cases were defined as individuals with an inherited PV in BRCA1/2 and controls were negative for BRCA1/2 or other known breast cancer risk gene PVs tested. Subjects were excluded if they had neoadjuvant therapy (hormonal or cytotoxic chemotherapy). Eligible cases were matched to control patients by age, grade, and stage. The Recurrence Score result was obtained by chart review; if not previously evaluated, Oncotype Dx assay was performed by Exact Sciences. Statistical analysis of the primary outcome used the paired t-test to determine mean difference in RS results between BRCA1/2 PV carriers and patients negative for a PV in BRCA1/2 using a 1:1 matched pairs design. Results: A total of 46 matched cases and controls were analyzed. Median age was 50 with a range of 28-74. Of the cases, 18 had a BRCA1 PV and 28 had a BRCA2 PV. Cases and controls were well matched for age (&amp;gt; 50 and ≤ 50); race, grade, stage, and progesterone receptor status. As expected, a higher number of BRCA1/2 carriers were treated with mastectomy while more of the controls received breast-conserving surgery. Chemotherapy was utilized more frequently in the cases (67.4%) versus the controls (54.4%). The average RS result was higher in the cases (27) than the controls (21.3) by a mean difference of 5.7 (p = 0.0195). Using Oncotype Dx cutoffs of low &amp;lt; 18, intermediate 18-30 and high ≥ 31, a statistically significant difference in RS result was noted in the cases versus controls. For cases in the highest risk group (Oncotype Dx ≥ 31), only 20% of their matches also had a score in the highest risk group while 35% had a score in the lowest risk group. Subgroup analysis showed that the cases had the largest difference in RS result from their controls in premenopausal women (age ≤ 50), BRCA1 carriers, and the node negative population. Conclusion We present one of the largest data sets available to date of a well-matched cohort of cases and controls which shows that BRCA1/2 PV carriers are more likely to have a higher Recurrence Score result than their matched controls when matched for age, grade, and stage. These findings suggest ER+ breast cancer in BRCA1/2 PV carriers is biologically more aggressive. Further investigation is warranted to evaluate how this important finding impacts adjuvant therapy recommendations for BRCA1/2 PV carriers. Citation Format: Poornima Saha, Ashley Aller, Amanda Deliere, Peter Hulick, Katharine Yao, Kristine Kuchta, Megan Sullivan, Allison DePersia. Application of 21-gene Breast Recurrence Score® assay to evaluate prognosis and benefit of adjuvant chemotherapy in BRCA1 and BRCA2 pathogenic variant carriers with early stage, estrogen receptor positive breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-03-15.

Abstract P6-01-11: A UK prospective multicentre decision impact, decision conflict and economic evaluation of the use of Oncotype DX® to guide chemotherapy in 680 women with hormone receptor positive, HER2 negative breast cancer and 1 to 3 nodes involved

Abstract Introduction: For a test to be of value, it needs to demonstrate that it is changing clinical decisions, improving clinical confidence and of economic benefit. This trial looked at the use of Oncotype DX Breast Recurrence Score ® (RS) assay against these criteria in 680 women with hormone receptor positive (HR+), HER2 negative early breast cancer with 1 to 3 lymph nodes positive (LN+) in the UK National Health Service (NHS) (5 teaching and 9 district general hospitals) between 2017 and 2022. Methods: Patients with LN+ early breast cancer who were willing and fit to receive chemotherapy (CT) were consented to join the trial. At the initial oncologists’ appointment, physicians were asked to state their preference for or against CT and their level of confidence in their decision on a scale of 1 to 5. Following receipt of the RS result physicians were asked to make a final decision for or against CT and similarly record their level of confidence. Descriptive analyses were used to characterize (1) patient and tumour characteristics, (2) change in treatment recommendations post-RS testing (by RS result and nodal status), and (3) change in physicians’ level of confidence post-RS testing (by RS result and nodal status). Average cost for chemotherapy and RS test price were used to estimate overall cost savings. Results: A total of 680 patients were recruited. 16 patients were excluded (5 failed samples, 5 withdrew consent, 3 HER2 positives, 2 with advanced disease, and 1 specimen delayed in transit), leaving 664 assessable patients. The median age was 58 years and 77.1% of women were post-menopausal. Most patients had a RS of 0-17 (n=400, 60.2%); while 206 (31%) had a RS of 18-30 and 58 (8.7%) had a RS of 31-100. Using post-RxPONDER cutoffs, 566 (85.2%) had an RS of 0-25; 98 (14.8%) had an RS of 26-100. Decision impact results: The decision impact results broken down by RS result and nodal status are detailed in Table 1. Of the 662 patients with complete decision impact data, in 359 (54.2%) the recommendation by the physician changed from CT+ hormone therapy (HT) to HT alone. In 286 (43.2%) cases the decision was unchanged and in 17 (2.6%) the recommendation changed from HT alone to CT+HT. Overall 342 (51.7%) cases were spared chemotherapy. Decision conflict results: The change in the physicians’ level of confidence by RS result and nodal status are detailed in Table 2. Of the 660 cases with complete decision conflict data, physicians reported an increase in confidence in their recommendations after receiving the RS in 363 (55.0%), confidence was unchanged in 219 (33.2%) and decreased confidence in 78 (11.8%) cases. Economic analysis: Using the estimates of Burdanov et al, the average costs of a course of chemotherapy in the UK is £6,000 to £7,000. An estimate of the overall cost saving of 342 courses is £2,064,00 to £2,408,000 and the overall cost of 664 RS assays at the list price of about £2580 (although an undisclosed discount applies to the NHS) is £1,713,120. This suggests that the use of RS assay represents a significant saving to the NHS. Conclusion: The use of Oncotype DX assay in node positive early breast cancer leads to about half of women being spared chemotherapy, a significant improvement in clinical confidence for oncologists and an economic saving to the health care system. Table 1 Pre- vs Post-Oncotype DX Treatment Recommendation by Physician According to Recurrence Score and Nodal Status Table 2 Change in Physicians’ Level of Confidence Post-Oncotype DX Testing According to Recurrence Score and Nodal Status Citation Format: Simon D. Holt, Priyadharshini Sai-Giridhar, Mark Verrill, Laura Pettit, Anna Rigg, Tamas Hickish, Caroline D. Archer, Anshu Wadhawan, Marianne Dillon, Jo Dent, Mark R. Nathan, Ludger Barthelmes, Shazza rehman, Paige Innis, Saira Khawaja. A UK prospective multicentre decision impact, decision conflict and economic evaluation of the use of Oncotype DX® to guide chemotherapy in 680 women with hormone receptor positive, HER2 negative breast cancer and 1 to 3 nodes involved [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-11.

Abstract P6-01-39: The impact of the 21-gene Recurrence Score® assay upon physician treatment recommendations in the neoadjuvant setting in lymph node-negative breast cancer patients in a multicenter prospective study in Quebec

Abstract Background: Although the role of the 21-gene Breast Recurrence Score® assay is well established to predict response to adjuvant chemotherapy in the setting of node-negative hormone receptor (HR)-positive, HER2-negative breast cancers (BC), fewer studies have evaluated the assay in the neoadjuvant setting. Due to the correlation between a high Recurrence Score® (RS) result and pathological complete response (pCR), the Breast Recurrence Score assay has been used to aid in selecting between chemotherapy (CT) or endocrine therapy. We wanted to further understand the impact of the assay upon physician treatment recommendations and the use of chemotherapy in this patient cohort. Methods: We conducted a multicenter, prospective, observational study in patients with clinically node-negative HR-positive, HER2-negative BC with T2-T3 disease being considered for neoadjuvant therapy. Physicians were required to complete two questionnaires indicating treatment choice, including CT, endocrine therapy, or surgery, prior to and post availability of RS result. Patients were followed up for 6 months after commencement of neoadjuvant therapy. The primary objective was to evaluate the change in the physician’s recommendation for neoadjuvant CT prior to and post assay results. As a secondary objective, we also evaluated the impact of the RS result on physician’s expressed level of confidence. Results: A total of 70 patients were enrolled between April 2018 and November 2021 at five hospital centers, as part of the McPeak Sirois Group of Quebec. The median age of the cohort was 60 years (range, 30 to 79 years). 24.3 % (n=17) of the cohort consisted of patients aged &amp;lt; 50 years, and 75.7% (n=53) were ≥ to 50 years. 29.0% (n=20) of the patients had a RS &amp;lt; 16, 39.1% (n=27) had a RS between 16-25, and 31.9% (n=22) had a RS &amp;gt; 25. For the entire cohort, the RS result led to a net reduction in chemotherapy recommendation by 33.3% (OR (odds of having CT post-RS recommendation versus pre-RS recommendation) = 0.23 [95% CI: 0.12-0.44]; P&amp;lt; 0.0001), and 39.2% net reduction in the use of chemotherapy at 6-month follow-up (OR = 0.18 [95% CI: 0.09-0.35]; P&amp;lt; 0.0001). Furthermore, the RS result led to a 35.3% net reduction in physician recommendation of CT for patients &amp;lt; 50 years (OR = 0.19 [95% CI: 0.04-0.83]; P=0.027) and a 32.7% net reduction for patients ≥ 50 years (OR = 0.24 [95% CI: 0.11-0.50]; P=0.0001). For patients with a RS &amp;lt; 16, there was a reduction in CT recommendation by 75.0%, and by 44.4% for patients with a RS between 16 - 25 (OR = 0.15 [95% CI: 0.06-0.38]; P&amp;lt; 0.0001). Moreover, RS results led to an increase in confidence in physician treatment decisions for 59.4% of patients (OR = 12.53 [95% CI: 5.46-28.78]; P&amp;lt; 0.0001). Conclusion: We determined that the 21-gene Breast Recurrence Score assay altered neoadjuvant treatment decisions, leading to a reduction in the use of chemotherapy by about one-third, regardless of age. Additionally, the assay increased physician confidence in their treatment recommendation for about 60% of patients. This demonstrates the potential clinical utility of the assay to decrease the use of CT in the neoadjuvant setting amongst HR-positive, node-negative BC patients in Quebec. Citation Format: Mariya Yordanova, Lucas Sideris, Pierre Dubé, Jean-Francois Boileau, Julie Lemieux, Catalin Mihalcioiu, Sylvie Levesque, Marie-Claude Guertin, Erica Patocskai, Rami Younan, André Robidoux, Saima Hassan. The impact of the 21-gene Recurrence Score® assay upon physician treatment recommendations in the neoadjuvant setting in lymph node-negative breast cancer patients in a multicenter prospective study in Quebec [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-39.

Abstract P2-23-14: Molecular characterization of HER2-low invasive breast carcinoma by quantitative RT-PCR using Oncotype DX®

Abstract Background: The DESTINY-Breast04 clinical trial demonstrated the superiority of trastuzumab deruxtecan (T-DXd) versus physician’s choice chemotherapy in HER2-low [immunohistochemistry (IHC) staining score 1+ or 2+ with no gene amplification by in-situ hybridization] metastatic breast cancer. The reproducibility of HER2 IHC category 0 versus 1+ scoring is poor in community practice. 89% of the DESTINY-04 participants were hormone receptor positive (HR+). In HR+ breast cancers, the Oncotype DX® (ODX) assay is widely used to estimate risk of recurrence and guide adjuvant chemotherapy selection. It also provides standardized quantification of HER2 mRNA expression by RT-PCR. Prior studies have demonstrated a high degree of overall concordance between central IHC and RT-PCR using ODX in HER2+ and HER2- cases. Here, we (i) compare HER2 mRNA levels quantified by ODX in HER2 IHC 0, 1+ and 2+ invasive breast carcinomas (IBC), (ii) compare the Recurrence Score® (RS) distribution across these three IHC categories and (iii) describe RS distribution and proliferation score in HER2-low IBC. Methods: 212 patients with HER2 IHC 0, 1+ and 2+ who were negative for HER2 gene amplification by FISH and had RS results were identified in Yale Department of Pathology archives. All US samples submitted for IBC ODX testing between 2005 to 2021 were reviewed in the Exact Sciences database. RS, quantitative HER2 mRNA expression, and proliferation scores were examined. IHC results were not available. Based on quantitative RT-PCR measures of HER2 expression, cases were assigned to: HER2 positive ≥11.5, equivocal ≥10.7 to &amp;lt; 11.5, and negative &amp;lt; 10.7 (1 unit increment is equivalent to approximately 2-fold change). Results: In the Yale cohort, 42%, 33%, and 25% of cases were IHC 0, 1+ and 2+, respectively. There was no difference in age or tumor grade by IHC category. HER2 mRNA levels increased across IHC categories (means 9.05, 9.16, 9.39, respectively), but in group-wise comparisons, only the IHC 0 compared to IHC 2+ reached statistical significance (Mann-Whitney test, p=0.0014). The RS scores were also modestly, but significantly higher in IHC 2+ compared to IHC 0 cases (mean 19.5 vs 14.51, Mann-Whitney p=0.034). Among IHC 0 and 1+ cases, 14% had RS &amp;gt;25, and among IHC 2+ cases, 32% had RS &amp;gt;25. All IHC 0 and 1+ cases were HER2 negative by RT-PCR. Of the HER2 2+ cases, there was one HER2 positive and one HER2 equivocal by RT-PCR. There was substantial variation in HER2 expression by RT-PCR in all IHC groups. In the Exact Sciences cohort, a total of 957,624 samples were analyzed. 0.8% of samples were HER2 positive, 1.2% were equivocal, and 98% were negative by RT-PCR. There was a wide range of RS results. Of the HER2 positive cases, 94.7% had RS &amp;gt;25. Among the HER2 equivocal cases 39.1% had RS &amp;gt;25, and among the HER2 negative cases, 15.5% had RS &amp;gt;25. Conclusions: HER2 IHC 0 and HER2 low IBC have a broad and overlapping range of HER2 expression by RT-PCR. Whether RT-PCR based HER2 expression predicts benefit from T-DXd is yet to be determined. Most HER2 low cases have RS ≤25, indicating no or limited benefit from adjuvant chemotherapy. Further studies are required to determine if patients with HER2 low IBC and RS ≤25, particularly with high anatomical risk, could benefit from adjuvant T-DXd. Table 1. Clinicopathologic and molecular characteristics by HER2 IHC group Table 2. Quantitative gene expression by HER2 IHC group Citation Format: Mariya Rozenblit, Hao-Kuen Lin, Nhu Thuy Can, Cynthia A. Flannery, Jess Hoag, Alekhya Akkunuri, Helen Bailey, Frederick Baehner, Lajos Pusztai. Molecular characterization of HER2-low invasive breast carcinoma by quantitative RT-PCR using Oncotype DX® [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-23-14.

Abstract P3-05-21: A novel AI-digital Test with an automated approach for grading and phenotyping breast cancer enriches recurrence score risk prediction in an Oncotype evaluated cohort

Abstract Background: Genomic testing such as OncotypeDx remains an important component of the treatmentdecision process for many breast cancer (BC) patients. Evidence from Sparano et al. JCO 2021;39:557-564 demonstrated the importance of combining clinical features such as tumor grade, size and age with the 21-gene recurrence score (i.e., RSClin). Given the challenges associated with reliability of BC grading as a prognostic feature, we sought to develop a broadly accessible AI-digital test (PDxBr) which included a BC AI-grade combined with clinical features (i.e., age, tumor size, stage and lymph node status) to predict recurrence risk in an Oncotype categorized cohort. Methods: We evaluated performance of the PDxBr test along with the AI-grade, clinical feature (i.e., age, size, tumor stage and LN status) and histology grade models in a subgroup analysis from a retrospective longitudinal clinical development validation study utilizing samples from breast cancer (BC) patients in the Mount Sinai Health Care System (NYC, NY) from 2004-2016. Eligible participants were ≥23 years old with infiltrating ductal or mixed ductal and lobular carcinoma of the breast (IDC) and all with an Oncotype RS, and a median 6-year follow-up. All participants had H&amp;E slides or paraffin blocks (for slide generation) from the resected BC specimen. H&amp;E slides were digitized (40X magnification) using a Philips UltraFast Digital slide scanner (Netherlands) and a single whole slide image (WSI) was selected for model development. The AUC/C-index was used to demonstrate performance. Results: 599 patients with Oncotype RS results were interrogated: 57% white, mean age 57, mean tumor size 1.3cm, 100% T1/2 and HR+ve, 55% grade 2, 26% grade 3 and 18% grade 1; 95% pN0 with 36 events (6%). 21 (60%) of events were local-regional recurrences. Of note, there were 55% histologic Grade 2 cases in this population. Combining Oncotype RS with assorted sub-models including histologic grade, clinical features, AI-grade, or PDxBr model in a SVRc analysis demonstrated incremental improvement in the C-index for predicting BC recurrence (Table 1). Conclusionss: Both PDxBr test and AI-grade when combined with Oncotype were superior to Oncotype alone, or Oncotype with grade or clinical features suggesting that the incorporation of an improved BC grade with Oncotype RS enhances overall risk discrimination. PDxBr is the first digital BC test combining automated AI-BC prognostic grade with clinical-pathologic features to predict risk of early-stage BC recurrence. Additional validation studies are underway to confirm these results. AUC comparison of Oncotype alone and then combined with histology grade, clinical data (age, stage, tumor size and LN pos), AI-grade, and the PDxBr model. Citation Format: Gerardo Fernandez, Marcel Prastawa, Richard Scott, Bahram Marami, Nina Shpalensky, Abishek Madduri, Krystal Cascetta, Mary Sawyer, Monica S. Chan, Giovanni Koll, Rebecca E. DeAngel, Alexander Shtabsky, Aaron Feliz, Thomas Hansen, Brandon Veremis, Carlos Cordon-Cardo, Jack Zeineh, Michael Donovan. A novel AI-digital Test with an automated approach for grading and phenotyping breast cancer enriches recurrence score risk prediction in an Oncotype evaluated cohort. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-21.

A new technique to achieve thick Tl2Ba2CaCu2O8 films for advanced applications

Tl2Ba2CaCu2O8 (Tl-2212) high-temperature superconductors (HTS) exhibit excellent superconductivity performance as their critical temperature (Tc) is higher than 100 K. However, the emergence of microcracks on the film surface restricts the thickness of the obtained Tl-2212 films, thus greatly limiting their scientific research and engineering application. Here, we fabricate crack-free Tl2Ba2CaCu2O8 (Tl-2212) films with a thickness of up to 5 μm on LaAlO3 (001) substrates synthesized by an improved strategy of a closed system. The impact of the thickness of the Tl-2212 films on their crystallographic orientations, Tc, critical current density (Jc) (0 T), critical current intensity (Ic) (0 T), and microwave surface resistance (Rs) was systemically explored. As the thickness increases, Tc values fluctuate slightly above 100 K while the variation of Jc follows the extended strong pinning theory. Ic of the 4 μm thick film stays around 80 A at 95 K, and the Rs result is less than 1 mΩ at 93 K, indicating their excellent performance at high temperatures. The interaction mechanism between the Jc and Rs of the Tl-2212 film is replenished in light of the quantitative exploration of Jc and Rs. This work on Tl-2212 films will promote their fundamental physics research and guide their potential applications in the electronics and electrical field. It can also serve as a reference for future research on other HTS materials.

A 10 year service evaluation of the survival of 439 patients with early oestrogen receptor positive breast cancer who underwent initial OncotypeDX ® testing to guide adjuvant chemotherapy decisions

ObjectiveTo explore the long-term outcome of patients who underwent Oncotype DX® testing. The relationship between the RS, adjuvant treatments received, and clinical outcomes across the entire range of RS results are reported. Methods10-year Kaplan–Meier estimates for distant recurrence/BC-specific survival (BCSS) in this cohort. The analysis included 439 patients. The follow-up time ranged from 14 to 142 months. All analyses were performed using the SPSS v20. ResultsMore than half of patients had low RS (<18) (55.6%) and 15.3% had RS ≥ 31. Chemotherapy use was consistent with the RS with 4.4%, 7.1%, 28.0%, 71.4% and 91.0% receiving adjuvant chemotherapy in patients with RS < 11, 11–17, 18–25, 26–30, and ≥31, respectively. The overall chemotherapy rate was 27.6%. Distant metastasis free survival (DMFS) differed significantly (P < 0.001) between the RS groups with 10 year DMFS rates of 99% (SE +/- 0.01) in the RS<11, 97% (SE +/- 0.03) in the RS 11–17, 97% (SE +/- 0.02) in the RS 18–25, 85% (SE +/- 0.1) in the RS 26–30 and 74% (SE +/- 0.08) in the RS ≥ 31 group. Ten year breast cancer specific survival also differed significantly (P < 0.001) between the RS groups; this risk was 100% (no deaths from breast cancer reported in the first 10 years) in RS < 11, 95% (SE +/- 0.03) in RS 11–17, 94% (SE +/- 0.04) in RS 18–25, 93% (SE +/- 0.07) in RS 26–30, and 79% (SE +/- 0.07) in the RS ≥ 31 group. ConclusionsUse of Oncotype DX RS does guide the treatment decisions and correlates with the BCSS and disease-free survival for ER positive, Her2 negative, early-stage, node negative breast cancer patients.

Population-based estimate for the correlation of the Oncotype Dx Breast Recurrence Score® result and Ki-67 IHC MIB-1 pharmDx in HR+, HER2−, node-positive early breast cancer

BackgroundThe United States Food and Drug Administration recently approved a Ki-67 immunohistochemistry (IHC) assay to identify patients with early breast cancer at high disease recurrence risk. The Oncotype Dx Breast Recurrence Score® assay has been validated in hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−) invasive breast cancer (IBC) to predict chemotherapy benefit and distant recurrence risk, regardless of nodal status. This study assessed the correlation between Recurrence Score® (RS) results and the Ki-67 IHC MIB-1 pharmDx assay.MethodsHR+, HER2−, N1 IBC samples with RS results were examined by Ki-67 IHC; 311 specimens were collected, including 275 without regard to RS (“unselected RS”) and 36 more with RS 26–100; 12 were lymph node negative upon pathology report review, and one had no Ki-67 score, leaving 262 unselected RS and 298 total samples. Spearman rank correlation was calculated using the unselected samples and a weighted rank correlation using all samples. A receiver operating characteristic (ROC) curve for predicting high RS (26–100) from Ki-67 was constructed.ResultsThe Spearman rank correlation between Ki-67 and RS results was moderately positive (unselected RS samples: 0.396; 95% confidence interval [CI] 0.288–0.493; all samples: 0.394; 95% CI 0.294–0.486). While 71% of samples with RS 26–100 had Ki-67 ≥ 20%, 75% with RS 0–25 had Ki-67 < 20%. ROC area under the curve was 0.792 (95% CI 0.725–0.859).ConclusionsThe moderately positive correlation is consistent with previous analyses suggesting the Oncotype Dx® assay and Ki-67 IHC MIB-1 assay should not be used interchangeably in clinical practice.

Recurrence Score® Result Impacts Treatment Decisions in Hormone Receptor-Positive, HER2-Negative Patients with Early Breast Cancer in a Real-World Setting-Results of the IRMA Trial.

Patients with hormone receptor-positive (HR+), HER2-negative (HER2-) early breast cancer (eBC) with a high risk of relapse often undergo adjuvant chemotherapy. However, only a few patients will gain benefit from chemotherapy. Since classical tumor characteristics (grade, tumor size, lymph node involvement, and Ki67) are of limited value to predict chemotherapy efficacy, multigene expression assays such as the Oncotype DX® test were developed to reduce over- and undertreatment. The IRMA trial analyzed the impact of Recurrence Score® (RS) assessment on adjuvant treatment recommendations. The RS result was assessed in patients with HR+/HER2- unilateral eBC with 0-3 pathologic lymph nodes who underwent primary surgical treatment at the Department for Women's Health of Tuebingen University, Germany. Therapy recommendations without knowledge of the RS result were compared to therapy recommendations with awareness of the RS result. In total, 245 patients underwent RS assessment. Without knowledge of the RS result, 92/245 patients (37.6%) would have been advised to receive chemotherapy. After RS assessment, 56/245 patients (22.9%) were advised to undergo chemotherapy. Chemotherapy was waived in 47/92 patients (51.1%) that were initially recommended to receive it. Chemotherapy was added in 11/153 patients (7.2%) that were recommended to not receive it initially. Using the RS result to guide adjuvant treatment decisions in HR+/HER2- breast cancer led to a substantial reduction of chemotherapy. In view of the results achieved in prospective studies, the RS result is among other risk-factors suitable for the individualization of adjuvant systemic therapy.

The Role of the 21-Gene Recurrence Score® Assay in Hormone Receptor-Positive, Node-Positive Breast Cancer: The Canadian Experience.

The management of patients with hormone receptor-positive breast cancer has changed dramatically with use of the 21-gene Recurrence Score® (RS) Assay. While the utility of the assay was initially demonstrated among node-negative patients, recent studies have also demonstrated the assay’s prognostic and predictive value in node-positive patients. In Canada, the RS assay is reimbursed by provincial health insurance plans, but not all provinces have approved the use of the assay for patients with node-positive disease. Here, we provide an overview of the clinical factors that influence physician recommendation of the RS assay and, alternatively, the impact of the RS assay on patient treatment decisions in Canada. We performed a comprehensive review of the impact of the assay upon physician treatment decisions and cost in node-positive breast cancer patients within Canada and other countries. Furthermore, we evaluated biomarkers that can predict the RS result, in addition to other genomic assays that predict recurrence risk among node-positive patients. Overall, the 21-gene RS assay was shown to be a cost-effective tool that significantly reduced the use of chemotherapy in node-positive breast cancer patients in Canada.