Oncotype DX 21-gene Recurrence Score Research Articles

Abstract GS02-08: Five-year outcomes of the IDEA trial of endocrine therapy without radiotherapy after breast-conserving surgery for postmenopausal patients age 50-69 with genomically-selected favorable Stage I breast cancer

Abstract Background: Multiple studies have shown a low risk of ipsilateral breast events (IBE) or other recurrences for selected patients age 65-70 or older with Stage I breast cancers treated with breast conserving surgery (BCS) and endocrine therapy (ET) without adjuvant radiotherapy (RT). We designed a prospective single-arm trial, IDEA (Individualized Decisions for Endocrine therapy Alone), to see if younger postmenopausal patients could also be successfully treated without RT, adding a genomic assay to classic selection factors. Methods: Postmenopausal patients aged 50-69 with pT1N0 unifocal invasive breast cancer with margins 2 mm or wider after BCS whose tumors were ER+, PR+, and Her2- with Oncotype DX 21-gene recurrence score (RS) 18 or lower were eligible to avoid RT if they consented to take at least 5 years of ET and surveillance on study. The primary endpoint was the rate of breast cancer recurrence at 5 years of follow-up after BCS. A valid 5–year assessment was defined as a clinical assessment within 4 months prior to the 5-year anniversary or later. Follow-up time was calculated from the date of BCS until first recurrence [ipsilateral breast events (IBE) or regional or distant failures] or to last clinical follow-up. The time-to-event endpoint was calculated using the product-limit method of Kaplan and Meier measured from the date of BCS. Results: 200 eligible patients were enrolled from 13 US institutions between June 2015 and October 2018. Median age was 63 years (IQR 58-66); mean RS was 11.2 (SD 4.8). Tumors were grade 1 in 85 patients, grade 2 in 109, and grade 3 in 6. Mean tumor size was 10 mm (SD 4.6). Lymphovascular invasion was present in 16 tumors and an extensive intraductal component in 11. Median follow-up time was 5.21 years (IQR 5.01-5.97); 8 of 14 patients with less than 56 months of follow-up were lost to follow-up. Overall and breast cancer-specific survival rates at 5 years were both 100%; 2 deaths occurred later than 5 years. The 5-year freedom from recurrence was 99% (95% CI, 96%-100%). One of the two events occurring by 5 years was an isolated axillary recurrence at 21 months treated with axillary dissection and breast and regional nodal irradiation. The other was an IBE at 49 months, treated with repeat BCS. Both these patients had been compliant with ET. Six additional patients recurred later than 5 years after BCS (5 IBEs, 1 IBE plus regional recurrence). Crude rates of IBE for the entire follow-up period for patients aged 50-59 and 60-69 were 3.3% (2/60) and 3.6% (5/140), respectively; crude rates of overall relapse were 5.0% (3/60) and 3.6% (5/140). Conclusions: This multicenter trial of ET without RT following BCS achieved a very low risk of relapse for postmenopausal patients with Stage I cancers using a genomic assay in combination with classic clinical and biologic features for treatment selection, including for patients younger than age 60. IDEA demonstrates a 5-year probability of recurrence consistent with or lower than the 4% risk estimated a priori, and the patients accrued were younger when compared to prior prospective trials (e.g., PRIME II, minimum age 65; CALGB 9343, minimum age 70; LUMINA, median age 67). The results of ongoing NRG BR007 trial, which randomly allocates women meeting these eligibility criteria to receive RT or not, and similar randomized and single-arm studies will help determine whether the option of avoiding initial RT can be offered to a broader group of women than current guidelines recommend. Long-term follow-up beyond the 5-year required period of ET will be important to determine if the risk of recurrence increases, particularly after discontinuation of ET. Citation Format: Reshma Jagsi, Kent Griffith, Eleanor Harris, Jean Wright, Abram Recht, Alphonse Taghian, Lucille Lee, Meena Moran, William Small, Candice Johnstone, Asal Rahimi, Gary Freedman, Mahvish Muzaffar, Bruce Haffty, Kathleen Horst, Simon Powell, Jody Sharp, Michael Sabel, Anne Schott, Mahmoud El-Tamer. Five-year outcomes of the IDEA trial of endocrine therapy without radiotherapy after breast-conserving surgery for postmenopausal patients age 50-69 with genomically-selected favorable Stage I breast cancer [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 GS02-08.

Omission of Radiotherapy After Breast-Conserving Surgery for Women With Breast Cancer With Low Clinical and Genomic Risk: 5-Year Outcomes of IDEA.

Multiple studies have shown a low risk of ipsilateral breast events (IBEs) or other recurrences for selected patients age 65-70 years or older with stage I breast cancers treated with breast-conserving surgery (BCS) and endocrine therapy (ET) without adjuvant radiotherapy. We sought to evaluate whether younger postmenopausal patients could also be successfully treated without radiation therapy, adding a genomic assay to classic selection factors. Postmenopausal patients age 50-69 years with pT1N0 unifocal invasive breast cancer with margins ≥2 mm after BCS whose tumors were estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor receptor 2-negative with Oncotype DX 21-gene recurrence score ≤18 were prospectively enrolled in a single-arm trial of radiotherapy omission if they consented to take at least 5 years of ET. The primary end point was the rate of locoregional recurrence 5 years after BCS. Between June 2015 and October 2018, 200 eligible patients were enrolled. Among the 186 patients with clinical follow-up of at least 56 months, overall and breast cancer-specific survival rates at 5 years were both 100%. The 5-year freedom from any recurrence was 99% (95% CI, 96 to 100). Crude rates of IBEs for the entire follow-up period for patients age 50-59 years and age 60-69 years were 3.3% (2/60) and 3.6% (5/140), respectively; crude rates of overall recurrence were 5.0% (3/60) and 3.6% (5/140), respectively. This trial achieved a very low risk of recurrence using a genomic assay in combination with classic clinical and biologic features for treatment selection, including postmenopausal patients younger than 60 years. Long-term follow-up of this trial and others will help determine whether the option of avoiding initial radiotherapy can be offered to a broader group of women than current guidelines recommend.

Identifying anatomopathological factors associated with a Oncotype DX 21-gene recurrence score higher than 25 in menopaused women.

e15156 Background: Oncotype DX recurrence score is a predictive assay clinically used to estimate the risk of distant recurrence for patients with hormone receptor positive (HR+) early breast cancer (EBC) and to predict the benefit of adjuvant chemotherapy, based on molecular factors of the tumor itself. This retrospective study examines the factors that are linked to a Recurrent score (RS) higher than 25, indicating adjuvant chemotherapy for menopaused women with hormone receptor positive early breast cancer. Methods: 157 patients diagnosed with HR+, HER 2 negative early breast cancer who underwent Oncotype DX testing during their treatment between November 2018 and December 2022 were included in the study. Of these 157 patients, 114 were older than 50 years old and with complete data. Univariate and multivariate logistic regression analysis were used to select pathological factors associated with a RS higher than 25. The receiver operating characteristic (ROC) curve was used to assess the optimal threshold of Estrogen receptor (ER), Progesterone receptor (RP) and Ki67. Results: Median age was 65 years (IQR: 59-71). 57 patients (47.5%) had a T1 tumor and 48% of patients had negative lymph nodes. Most of the patients had a Scarff-Bloom-Richardson (SBR) grade 1 (12%) or grade 2 tumor (70%), and 18% of the patients had grade 3 breast cancer. The cell proliferation marker Ki67 was higher than 30 % for 28 patients (23%). The RS was higher than 25 for 17 patients out of 120 patients. Multivariate logistic regression analysis showed that Ki67 higher than 30% was significant associated with RS > 25 (p = 0.01). To predict a RS > 25, the optimal threshold were respectively 80% for the PR, 90% for the ER and 30% for the Ki67. The area under the ROC curve (AUC) were respectively 0.70, 0.60 and 0.88. With the threshold of 30% for Ki67, the sensitivity was 0.76 and specificity 0.89. Conclusions: The use of the Oncotype DX test is validated and useful to better decide the absence of chemotherapy indication in adjuvant situation in some patients with HR+ cancers. However, access to it remains difficult and expensive in some countries with limited resources. Ki67 and SBR grade could be used as an indication for adjuvant chemotherapy but cannot replace Oncotype DX.

Multiparametric MR Imaging Radiomics Signatures for Assessing the Recurrence Risk of ER+/HER2- Breast Cancer Quantified With 21-Gene Recurrence Score.

While the Oncotype DX 21-gene recurrence score (RS) has been recommended for guiding ER+/HER2- breast cancer treatment decisions, it is limited by cost and availability. To develop a multiparametric MRI-based radiomics model for assessing ER+/HER2- breast cancer patients' 21-gene RS. Retrospective. A total of 151 patients with pathologically confirmed ER+/HER2- breast cancers, who underwent preoperative breast MR examinations and 21-gene expression assays, divided into training (n=106) and validation (n=45) cohorts. T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and dynamic contrast-enhancement (DCE) sequence at 1.5T or 3T. A total of 1046 radiomics features were extracted from each MRI sequence with a manual lesion segmentation method. After feature dimension reduction by the recursive feature elimination method and dataset balance by the synthetic minority oversampling technique, linear support vector machine classifier models were built to distinguish high RS (RS ≥ 26) from low RS (RS < 26) from T2WI, DWI apparent diffusion coefficient (ADC) maps, DCE and their combination (multiparametric). A model based on clinical characteristics and a fusion model combining clinical characteristics and multiparametric MRI were also built. Receiver operating characteristic (ROC) curve analysis and De Long's test with Bonferroni correction were used. A P value <0.01 was considered statistically significant. The area under the ROC curve (AUC) value of multiparametric radiomics model was 0.92, significantly higher than DCE (0.83), T2WI (0.78), and ADC (0.77) models in the training cohort. The radiomics model also achieved good performance in the validation cohort (AUC=0.77). The fusion model had significantly higher performance than the clinical model in both the training (AUC=0.92 and 0.64, respectively) and validation cohorts (AUC=0.78 and 0.62, respectively). The proposed multiparametric MRI-based radiomics models may have potential to help distinguish ER+/HER2- breast cancer patients' recurrence risk. 3. Stage 2.

Clinical Utility of Genomic Assay in Node-Positive Early-Stage Breast Cancer.

Breast cancer (BC) is the most common malignancy among women in Canada. Adjuvant treatment in early BC can reduce the risk of BC recurrence. Historically, the decision for adjuvant chemotherapy for early BC was made only based on clinical and tumour characteristics. In recent years, there has been an effort toward developing genomic assays as a predictive and prognostic tool to improve precision in estimating disease recurrence, sensitivity to systemic treatment and ultimately with clinical utility for guidance regarding adjuvant systemic treatment(s). There are various commercial genomic tests available for early-stage ER+/HER-2 negative BC. This paper will review the Oncotype DX 21-gene Recurrence Score (RS), MammaPrint, EndoPredict, Prosigna®, and Breast Cancer Index (BCI) genomic assays. We will also focus on these genomic assays’ clinical application and utility in node-positive early-stage BC based on the most recent evidence and guidance recommendations.

Ovarian cycle stage critically affects 21-gene recurrence scores in Mmtv-Pymt mouse mammary tumours

BackgroundThe Oncotype DX 21-gene Recurrence Score is predictive of adjuvant chemotherapy benefit for women with early-stage, estrogen receptor (ER)-positive, HER2-negative breast cancer. In premenopausal women, fluctuations in estrogen and progesterone during the menstrual cycle impact gene expression in hormone-responsive cancers. However, the extent to which menstrual cycling affects the Oncotype DX 21-gene signature remains unclear. Here, we investigate the impact of ovarian cycle stage on the 21-gene signature using a naturally cycling mouse model of breast cancer.MethodsER-positive mammary tumours were dissected from naturally cycling Mmtv-Pymt mice at either the estrus or diestrus phase of the ovarian cycle. The Oncotype DX 21-gene signature was assessed through quantitative real time-PCR, and a 21-gene experimental recurrence score analogous to the Oncotype DX Recurrence Score was calculated.ResultsTumours collected at diestrus exhibited significant differences in expression of 6 Oncotype DX signature genes (Ki67, Ccnb1, Esr1, Erbb2, Grb7, Bag1; p ≤ 0.05) and a significant increase in 21-gene recurrence score (21.8 ± 2.4; mean ± SEM) compared to tumours dissected at estrus (15.5 ± 1.9; p = 0.03). Clustering analysis revealed a subgroup of tumours collected at diestrus characterised by increased expression of proliferation- (p < 0.001) and invasion-group (p = 0.01) genes, and increased 21-gene recurrence score (p = 0.01). No correlation between ER, PR, HER2, and KI67 protein abundance measured by Western blot and abundance of mRNA for the corresponding gene was observed, suggesting that gene expression is more susceptible to hormone-induced fluctuation compared to protein expression.ConclusionsOvarian cycle stage at the time of tissue collection critically affects the 21-gene signature in Mmtv-Pymt murine mammary tumours. Further studies are required to determine whether Oncotype DX Recurrence Scores in women are similarly affected by menstrual cycle stage.

Discordance in 21-gene recurrence scores between paired breast cancer samples is inversely associated with patient age

BackgroundThe Oncotype DX 21-gene Recurrence Score is a genomic-based algorithm that guides adjuvant chemotherapy treatment decisions for women with early-stage, oestrogen receptor (ER)-positive breast cancer. However, there are age-related differences in chemotherapy benefit for women with intermediate Oncotype DX Recurrence Scores that are not well understood. Menstrual cycling in younger women is associated with hormonal fluctuations that might affect the expression of genomic predictive biomarkers and alter Recurrence Scores. Here, we use paired human breast cancer samples to demonstrate that the clinically employed Oncotype DX algorithm is critically affected by patient age.MethodsRNA was extracted from 25 pairs of formalin-fixed paraffin-embedded, invasive ER-positive breast cancer samples that had been collected approximately 2 weeks apart. A 21-gene signature analogous to the Oncotype DX platform was assessed through quantitative real-time PCR, and experimental recurrence scores were calculated using the Oncotype DX algorithm.ResultsThere was a significant inverse association between patient age and discordance in the recurrence score. For every 1-year decrease in age, discordance in recurrence scores between paired samples increased by 0.08 units (95% CI − 0.14, − 0.01; p = 0.017). Discordance in recurrence scores for women under the age of 50 was driven primarily by proliferation- and HER2-associated genes.ConclusionThe Oncotype DX 21-gene Recurrence Score algorithm is critically affected by patient age. These findings emphasise the need for the consideration of patient age, particularly for women younger than 50, in the development and application of genomic-based algorithms for breast cancer care.

Abstract P3-08-06: Lymphovascular invasion (LVI), the 21-gene recurrence score, and race in early estrogen receptor-positive, HER2-negative breast cancer: A national cancer database (NCDB) analysis

Abstract Background: LVI and black race are associated with poorer prognosis in early breast cancer (BCA). The Oncotype DX 21-gene Recurrence Score (RS) is both prognostic for recurrence and predictive of chemotherapy benefit in estrogen-receptor positive (ER+), HER2-negative (HER2-) early BCA. Black women enrolled on the TAILORx trial, which assigned or randomized women with hormone receptor-positive, HER2-, node-negative (N0) BCA to adjuvant therapy based on RS, had a 1.4-fold higher risk of recurrence than white women, despite similar RS distribution, treatment, and reported adherence to endocrine therapy. No prior studies have evaluated the impact of LVI, RS, and race in the same population, to assess whether LVI contributes to racial disparities or adds prognostic information to RS. Methods: Female patients diagnosed between 1/1/2010 (the first year LVI was collected by NCDB) and 1/1/2014 with ER+ HER2- BCA, measuring up to 5 cm, with 0-3 involved axillary nodes, treated with definitive surgery as first treatment, and with numeric RS available, were identified from the 2005-2016 NCDB database. Bivariate associations between two categorical variables were examined using the chi-square test. Multivariate Cox proportional hazards model were used to assess association between LVI, chemotherapy and RS on overall survival (OS), while adjusting age, race, tumor size, grade, LN status, median income, and education level. The estimated HR for each variable in the model, along with its 95% CI, was reported. All tests are two-sided with significance level ≤5%. All analyses were conducted using SAS 9.4. Results: 77,425 women met inclusion criteria, 65,018 N0 and 12,407 node-positive (N+). 2870 deaths were seen. LVI was present in 12.7% of cases, and associated with poor tumor grade, high RS ≥26, and N+ (all p&amp;lt;0.0001), but not black race. Black race was associated with with larger tumor size, poorer tumor grade, high RS ≥26, and N+ (all p&amp;lt;0.0001). Tumor-related factors associated with poorer OS included LVI (p&amp;lt;0.0001), larger tumor size (21-50 vs 0-20 mm, p&amp;lt;0.0001), higher RS (11-25 vs 0-10, p=0.039, ≥26 vs 0-10, p&amp;lt;0.0001), poor histologic grade (3 vs 1, p&amp;lt;0.0001) and N+ (p&amp;lt;0.0001). Demographic factors associated with worse OS were older age (p&amp;lt;0.0001) and black race (p&amp;lt;0.0001). Median income was inversely associated with OS (p&amp;lt;0.0001). LVI correlated with poor grade and higher RS, and with N+ (p&amp;lt;0.0001). LVI was associated with worse OS in the entire cohort [HR 1.241 (95% CI 1.120, 1.375, p&amp;lt;0.0001)] and in N0 patients [HR 1.355 (95% CI 1.195, 1.536, p&amp;lt;0.0001)], but not in N+. LVI was associated with worse OS in N0 patients with RS 11-25 [HR 1.292 (95% CI 1.074, 1.555)] and ≥26 [HR 1.553 (95% CI 1.277, 1.888)], but not in patients with RS 0-10. Test for interaction between RS and LVI was not significant. Conclusion: LVI adds prognostic information in ER+, HER2-, N0 BCA with RS 11-100. Black race is associated with worse OS, and with adverse prognostic factors such as high grade and high RS, but not with LVI. Citation Format: Della Makower, Juan Lin, Xiaonan Xue, Joseph A Sparano. Lymphovascular invasion (LVI), the 21-gene recurrence score, and race in early estrogen receptor-positive, HER2-negative breast cancer: A national cancer database (NCDB) analysis [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-06.

Impact of 21-Gene Expression Assay on Clinical Outcomes in Node-Negative ≤ T1b Breast Cancer.

Prior to the advent of Oncotype DX 21-gene recurrence score (oDX) assay, the National Comprehensive Cancer Network (NCCN) guideline supported omission of adjuvant chemotherapy in patients with ≤ 1cm (T1b) hormone receptor-positive (HR +), human epidermal growth factor receptor 2 (HER2-) node tumors. However, around 30% of these patients would have an oDX recurrence score that warrants consideration of adjuvant chemotherapy. To clarify the potential benefit of oDX in these patients, we performed a retrospective analysis comparing clinical outcomes of women with T1a or T1b, N0 HR + HER2- according to performance of oDX. After receiving institutional review board (IRB) approval, an institutional database was queried to identify patients with HR + HER2- ≤ T1bN0 tumors (n = 2307) diagnosed between 2009 and 2018. Patients were further stratified by recurrence score (RS) defined as low (< 18), intermediate (18-30), or high (> 30). Log-rank, Kaplan-Meier, and inverse probability of treatment weighting (IPW) analyses were used to compare disease-free survival (DFS) and overall survival (OS) across groups. Performance of oDX (n = 1149, 49.8%) was associated with larger tumors, younger age, and White race. On univariate analysis, performance of oDX was associated with improved OS (P < 0.01). On multivariate IPW analysis, performance of oDX lengthened DFS by an average of 16.5months, while OS was similar between groups (P < 0.01 and P = 0.73). The improved DFS was mainly driven by those with tumors ≥ T1b. Overall, outcomes were excellent regardless of oDX testing. Performance of oDX testing was associated with improved DFS in patients with tumors ≥ T1b. Our results support routine use of oDX testing in patients with tumors ≥ T1b.

Abstract P4-09-13: A prognostic predictive model based on the correlation of standard clinicopathologic characteristics with oncotype Dx 21-gene recurrence score for node-negative and ER positive breast cancer

Abstract BACKGROUND: The Oncotype Dx Breast Cancer Assay (21-gene recurrence assay) is a prognostic tool that produces a recurrence score, which estimates the probability of distant recurrence within 10 years, given 5 years of adjuvant endocrine therapy as well as predicts benefit from adjuvant chemotherapy. The primary objective of this study was to explore if standard clinicopathologic variables independently correlate to the recurrence score. As a secondary objective, we explored if a model based on the clinicopathologic variables can accurately predict recurrence score. METHODS: We conducted a retrospective chart review of 507 patients with node-negative, estrogen receptor (ER) positive breast cancer from the UF Health Cancer Center at Orlando Health. Of the 507 patients, 84 did not meet inclusion criteria (n = 423). The following factors were correlated with recurrence score (RS): age, tumor size, ER, PR, ki67, HER2 (IHC), HER2 (FISH), and tumor grade. Although the RS is a continuous variable, scores are also used to categorize patients into three risk groups: low (RS&amp;lt;18), intermediate (18≤RS&amp;lt;31), and high (RS≥31). This study evaluated variation of the HER2 levels within this subset of HER2 negative patients. RESULTS: In univariate analysis, there were no significant correlations between age, ER, tumor size, Ki67 and RS. There were statistically significant correlations between PR (r=-.42, p&amp;lt;.001), HER2 (IHC) (r=.097, p&amp;lt;.05), HER2 (FISH) (r=0.40, p&amp;lt;.001), and tumor grade (r=0.37, p&amp;lt;.001) and RS. As a second step, we used these results and clinical expertise to guide a predictive model. As expected, independently, PR and tumor grade were significant predictors of RS (βs= -.096, .37, respectively; p&amp;lt;.05). However, HER2 (IHC) was not, β=.097, p = .054. As a final step, three pathologic factors (PR, HER2 by IHC, and tumor grade) were used to predict recurrence score. In the multivariate analysis, we found a statistically significant model, (R = 0.54, RAdj = .30; F (3, 399) = 57.17, p &amp;lt; .001), where, PR (β= -.096), HER2 (IHC) (β= 2.007), and tumor grade (β= 4.778). Concordance with the 21-gene assay was as follows: 76.0%, 54.5%, and 66.7% for low, intermediate, and high-risk groups, respectively. As clinical guidelines are not firmly established for the use of chemotherapy in the intermediate risk group it is also valuable to estimate the two-step discordance, an estimated RS that is high, when the 21-Gene recurrence score is low and vice versa. The two-step discordance was 2.2% and 0.0% for the low and high risk groups, respectively. CONCLUSION: The data presented here suggests that it may be possible to create a model based on standard clinicopathologic parameters to predict the 21-gene recurrence score in node-negative, ER positive breast cancer patients. In practice, a 21-gene recurrence score assay is not always possible. We present an option to identify patients whose risk category can be confidently determined from the standard clinicopathologic variables alone, thereby reducing medical cost. Admittedly, this model has not undergone validation nonetheless, the data suggest the potential for a novel; low-cost; high reach diagnostic tool. Citation Format: Mankbadi MR, Luo Y, Yasin M, Ben Khallouq B, Moroose R. A prognostic predictive model based on the correlation of standard clinicopathologic characteristics with oncotype Dx 21-gene recurrence score for node-negative and ER positive breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-09-13.

Relevance of Spatial Heterogeneity of Immune Infiltration for Predicting Risk of Recurrence After Endocrine Therapy of ER+ Breast Cancer.

Despite increasing evidence supporting the clinical utility of immune infiltration in the estrogen receptor-negative (ER-) subtype, the prognostic value of immune infiltration for ER+ disease is not well defined. Quantitative immune scores of cell abundance and spatial heterogeneity were computed using a fully automated hematoxylin and eosin-stained image analysis algorithm and spatial statistics for 1178 postmenopausal patients with ER+ breast cancer treated with five years' tamoxifen or anastrozole. The prognostic significance of immune scores was compared with Oncotype DX 21-gene recurrence score (RS), PAM50 risk of recurrence (ROR) score, IHC4, and clinical treatment score, available for 963 patients. Statistical tests were two-sided. Scores of immune cell abundance were not associated with recurrence-free survival. In contrast, high immune spatial scores indicating increased cell spatial clustering were associated with poor 10-year, early (0-5 years), and late (5-10 years) recurrence-free survival (Immune Hotspot: LR-χ2 = 14.06, P < .001, for 0-10 years; LR-χ2 = 6.24, P = .01, for 0-5 years; LR-χ2 = 7.89, P = .005, for 5-10 years). The prognostic value of spatial scores for late recurrence was similar to that of IHC4 and RS in both populations, but was not as strong as other tests in comparison for recurrence across 10 years. These results provide a missing link between tumor immunity and disease outcome in ER+ disease by examining tumor spatial architecture. The association between spatial scores and late recurrence suggests a lasting memory of protumor immunity that may impact disease progression and evolution of endocrine treatment resistance, which may be exploited for therapeutic advances.

A pilot laboratory study comparing the 21-gene assay and PAM50-ROR.

11003 Background: The Oncotype DX 21-gene Recurrence Score assay was developed in endocrine-treated patients (pts) and validated as a predictor of 10-yr distant recurrence risk and chemotherapy benefit in ER+ early-stage invasive breast cancer. The Prosigna assay (ROR) which uses 46 of the PAM50 genes, was validated on centrally processed samples as a prognostic assay only in endocrine treated, post-menopausal pts. To date no direct comparison data on paired samples from the same patients for these two assays has been reported and yet it’s frequently believed that these assays are interchangeable. We performed a pilot study comparing test results from the two assays obtained from the same tumor blocks. Methods: Sequential breast cancer tumors from Marin Medical Laboratories with sufficient tumor material were tested with the standard 21-gene Recurrence Score assay. 40 cases stratified by the Recurrence Score (20 low, 10 intermediate and 10 high) were sent to an independent laboratory where the Prosigna assay for ROR and intrinsic subtype was performed with the operators blinded to the Recurrence Score results. Descriptive statistics were calculated for the results obtained from the two assays. Results: Of the 40 pts, 3 were excluded due to low RNA signal in the Prosigna assay and 4 were ER(-) by RT-PCR. Of the 33 remaining cases, 24 were ductal, 7 lobular and 2 other; 27 were N- and 6 were N+. The Spearman rank correlation between Recurrence Score and ROR was 0.40 (95% CI 0.06 – 0.65). Risk group assignment (low/intermediate/high) between Recurrence Score and ROR was in agreement in 56% (15/27) of N(-) pts. Prosigna classified 19 as luminal A, 12 as luminal B, 2 as HER2 enriched and 0 as basal. In both the luminal A and B groups there was a wide range of Recurrence Score results. Conclusions: Consistent with other comparisons between expression-based assays, it should not be assumed that these assays are interchangeable. While additional data from a larger independent analysis is needed, this pilot suggests that there is only a modest agreement between the Recurrence Score and ROR, with almost half of N(-), ER+ pts classified differently.

Abstract P1-08-03: Prediction of response to neoadjuvant chemotherapy in estrogen receptor positive (ER+) breast cancer by IHC4 or Ki67 alone

Abstract Aims To determine whether IHC4 score assessed on pre-treatment core biopsies (i) predicts response to neoadjuvant chemotherapy in ER positive breast cancer; (ii) provides more predictive information than Ki67 alone. Background The IHC4 score, a composite of ER, PgR, Ki67 and HER2 scores provides prognostic information similar to the OncotypeDx 21-gene Recurrence Score in ER + primary breast cancer treated with endocrine therapy but it is unknown if it also predicts response to chemotherapy. Pathological complete response (pCR) following neoadjuvant chemotherapy is established as an intermediate marker of long-term outcome. More recently the residual cancer burden (RCB) has also been shown to be prognostic, with those patients with minimal residual disease (RCB1) following neoadjuvant chemotherapy having a similar prognosis to those with a pCR (RCB0). The development of these intermediate markers provides an opportunity to study the predictive role of pre-treatment biomarkers for benefit to a particular therapy. Methods A total of 114 ER+ patients treated with neoadjuvant chemotherapy at the Royal Marsden Hospital between 2002-2010 were included in the study. An assessment of the excision specimen was made for residual disease. IHC4 was determined on pre-treatment core biopsies, blinded to clinical outcome, by immunohistochemistry using quantitative scoring of ER (H-score), PgR (%) and Ki67 (%). Determination of HER2 status was made by immunohistochemistry and fluorescent in situ hybridization for 2+ cases. IHC4 and Ki67 scores were tested for their association with pCR rate and RCB score. Results 19 (17%) of the 114 patients and 9 (10%) of the 90 HER2-ve cases showed a pCR. Ki67 and the IHC4 score were both positively associated with achievement of pCR (P&amp;lt;10-7 and P&amp;lt;10-9 respectively) and RCB0+1 (P&amp;lt;10-5 and P&amp;lt;10-9 respectively) following neoadjuvant chemotherapy in all patients. Rates of RCB0+1 were 45% and 66% in the highest quartiles of Ki67 and IHC4 scores respectively. In ER + HER2-ve cases pCR and RCB0+ 1 rates were 35% and 39%, respectively in the highest quartile of IHC4 and 30% and 39%, respectively in the highest quartile of Ki67 (Table 1). There were no pCRs in the lower half of IHC4 or Ki67 scores. Conclusions A high IHC4 was strongly predictive of a pCR or near pCR in ER + breast cancers following neoadjuvant chemotherapy. Ki67 was an important component of this predictive ability. Response according to IHC4 and Ki67 quartile in HER2 negative, ER+ breast cancersIntermediate endpointpCRpCRRCB0+RCB1RCB0+RCB1ScoreIHC4Ki67IHC4Ki67Quartile 10% (0/22)0% (0/22)5% (1/22)9% (2/22)Quartile 20% (0/23)0% (0/23)4% (1/23)0% (0/23)Quartile 35%(1/22)9% (2/23)9% (2/22)9% (2/23)Quartile 435% (8/23)30% (7/23)39% (9/23)39% (9/23) Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-03.

A prospective clinical utility study of the impact of the 21-gene recurrence score assay (Oncotype DX) in estrogen receptor positive (ER+) node negative (pN0) breast cancer in academic Canadian centers.

549^ Background: The Oncotype DX 21-gene Recurrence Score assay (RS) can potentially predict the magnitude of chemotherapy benefit in patients with stage I-II, node-negative, ER+ disease who will be treated with tamoxifen for 5 years. While use in the United States has grown significantly since its introduction, it is not yet routinely ordered by oncologists in most parts of Canada. The primary purpose of this study was to measure the impact of the Oncotype DX test on the physician’s treatment recommendation in ER+ pN0 breast cancer in British Columbia. Methods: After providing informed consent, patients and medical oncologists completed respective pre-RS questionnaires indicating their treatment preferences and level of confidence and a decisional conflict scale (patients only). At a subsequent visit, after the RS result was known and discussed, the patient and oncologist completed a second set of questionnaires. The proportion of physician treatment recommendations that changed from baseline to follow-up (post RS) were calculated with 95% confidence interval (CI). A prospective health economic (HE) analysis was also performed. Results: From May 2010 to July 2011, two participating BCCA centres enrolled 156 patients. Of the 150 for whom successful RS assay results were obtained, physicians changed their chemotherapy recommendation in 45 cases (30%; 95% CI 22.8-38.0%); either to add (10%; 95% CI 5.7-16.0%) or omit (20%; 95% CI 13.9-27.3%) adjuvant chemotherapy. As a secondary end-point, in 84 cases (56%; 95% CI 47.7-64.1%) there was a change in either the planned chemo and/or endocrine therapy recommendation. There was an overall significant improvement in physician confidence post RS (p &lt; 0.001). Patient decisional conflict also significantly decreased following the RS assay (p &lt; 0.001). The HE analysis is ongoing and will be presented separately. Conclusions: Within the context of a publicly funded health care system, the RS assay significantly affects adjuvant treatment recommendations in ER+ node negative breast cancer, in addition to reducing patient decisional conflict.

RecurrenceOnline: an online analysis tool to determine breast cancer recurrence and hormone receptor status using microarray data

In the last decades, several gene expression-based predictors of clinical behavior were developed for breast cancer. A common feature of these is the use of multiple genes to predict hormone receptor status and the probability of tumor recurrence, survival or response to chemotherapy. We developed an online analysis tool to compute ER and HER2 status, Oncotype DX 21-gene recurrence score and an independent recurrence risk classification using gene expression data obtained by interrogation of Affymetrix microarray profiles. We implemented rigorous quality control algorithms to promptly exclude any biases related to sample processing, hybridization and scanning. After uploading the raw microarray data, the system performs the complete evaluation automatically and provides a report summarizing the results. The system is accessible online at http://www.recurrenceonline.com . We validated the system using data from 2,472 publicly available microarrays. The validation of the prediction of the 21-gene recurrence score was significant in lymph node negative patients (Cox-Mantel, P = 5.6E-16, HR = 0.4, CI = 0.32-0.5). A correct classification was obtained for 88.5% of ER- and 90.5% of ER + tumors (n = 1,894). The prediction of recurrence risk in all patients by using the mean of the independent six strongest genes (P < 1E-16, HR = 2.9, CI = 2.5-3.3), of the four strongest genes in lymph node negative ER positive patients (P < 1E-16, HR = 2.8, CI = 2.2-3.5) and of the three genes in lymph node positive patients (P = 3.2E-9, HR = 2.5, CI = 1.8-3.4) was highly significant. In summary, we integrated available knowledge in one platform to validate currently used predictors and to provide a global tool for the online determination of different prognostic parameters simultaneously using genome-wide microarrays.