Distribution of 21-Gene Recurrence Scores Among Breast Cancer Histologic Subtypes

Breast Cancer Human Epidermal Growth Factor Receptor 2 mRNA Molecular Testing Compared to Immunohistochemistry with Correlation to Neoadjuvant Therapy Response

BACKGROUND: Breast cancer is the most common cancer type among women worldwide. Human epidermal growth factor receptor 2 (HER-2) is amplified in 10–34% of breast carcinomas and offers a therapeutic option from HER2-targeted therapy. Hence, HER2 is tested routinely in all breast cancer patients using immunohistochemistry (IHC) and in situ hybridization. Yet, some pitfalls do exist due to tumoral heterogeneity, inter and intrapersonal variations. mRNA expression assays can provide an alternative method for accurately measuring HER-2 avoiding these limitations. AIM: Comparing results of mRNA gene expression analysis for HER2 with IHC results and correlating it with the therapy response. MATERIALS AND METHODS: One hundred breast cancer core biopsies were tested for HER-2 using IHC and the same blocks were sectioned and tested for mRNA gene expression for HER2 by the Xpert breast cancer STRAT4 device. RESULTS: Concordance rate between mRNA expression and IHC for HER-2 was 93% with Kappa measurement showing perfect agreement (κ = 0.81, 95% CI, p < 0.0005). CONCLUSION: The study reveals high concordance between HER2 measurement using IHC and mRNA analysis. Molecular testing can provide an effective standardized method for HER-2 measurement in breast cancer patients.

Disparities in Access to Systemic Treatment for Breast Cancer in Thailand and Major Asian Territories

Purpose

Methods

Results

Conclusion

A preliminary report of head-to-head comparison of 18-gene-based clinical-genomic model and oncotype DX 21-gene assay for predicting recurrence of early-stage breast cancer

Background

The information of Oncotype DX applied in Asian breast cancer patients is limited. A recurrence index for distant recurrence (RI-DR) has been developed for early-stage breast cancer (EBC) from tumor samples in Chinese patients. In this study, we compared the prognostic performance of the Oncotype DX (ODx) recurrence score (RS) with the RI-DR for any recurrence risk type.

Materials and methods

One hundred thirty-eight (138) patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative EBC who were previously tested with ODx were included for testing with the RI-DR. The cutoff score to partition the low- and high-risk patients was 26 for RS and 36 for RI-DR. The primary endpoint was recurrence-free survival (RFS).

Results

The concordance between the RI-DR and RS was 83% in N0 patients and 81% in node-positive patients when the RS score cutoff was set at 26. With a median follow-up interval of 36.8 months, the 4-year RFS for the high- and low-risk groups categorized by the RS were 61.9% and 95.0%, respectively (hazard ratio: 10.6, 95.0% confidence interval [CI]: 1.8–62.9). The 4-year RFS in the high- and low-risk groups categorized by the RI-DR were 72.6% and 98.5%, respectively (hazard ratio: 18.9, 95% CI: 1.8–138.8).

Conclusion

This paper illustrated the performance of RI-DR and ODx RS in breast cancer women in Taiwan. There was high concordance between the RI-DR and RS. The RI-DR is not inferior to the RS in predicting RFS in EBC patients. This study will fill the gap between the current and best practice in Chinese patients.

Comparison of the Distribution Pattern of 21-Gene Recurrence Score between Mucinous Breast Cancer and Infiltrating Ductal Carcinoma in Chinese Population: A Retrospective Single-Center Study

Purpose

This retrospective study aimed to evaluate the distribution pattern and prognostic value of 21-gene recurrence score (RS) in Chinese patients with mucinous breast cancer (MC) and compared with infiltrating ductal carcinoma (IDC).

Materials and Methods

Patients diagnosed with MC or IDC from January 2010 to January 2017 were retrospectively recruited. Reverse transcriptase–polymerase chain reaction assay of 21 genes was conducted to calculate the RS. Univariate and multivariate analyses were performed to assess the association between RS and clinicopathological factors. Survival outcomes including disease-free survival (DFS) and overall survival (OS) were estimated by Kaplan-Meier method and compared by log-rank test.

Results

The MC cohort included 128 patients and the IDC cohort included 707 patients. The proportions of patients with a low (RS < 18), intermediate (18-30), or high risk (RS > 30) were 32.0%, 48.4%, and 19.5% in MC cohort, and 26.9%, 46.8% and 26.3% in IDC cohort. The distribution of RS varied significantly according to different Ki-67 index and molecular subtype in both cohorts. Moreover, the receipt of chemotherapy was associated with RS in both cohorts. Among patients with MC, tumor stage was related to the DFS (p=0.040). No significant differences in DFS and OS were found among MC patients in different RS risk groups (OS, p=0.695; DFS, p=0.926).

Conclusion

RS was significantly related to Ki-67 index and molecular subtypes in MC patients, which is similar in IDC patients. However, RS was not able to predict DFS and OS in patients with MC.

Should women with early breast cancer under 40 years of age have a routine 21-gene recurrence score testing: A SEER database study

PURPOSE

To investigate the effect of 21-gene recurrence score (RS) on chemotherapy-decision making and prognosis in breast cancer patients aged <40 years.

METHODS

Using the Surveillance, Epidemiology, and End Results program, we included patients aged <40 years with tumor size ≤5 cm, node negative, and estrogen receptor-positive breast cancer between 2004 and 2015. Correlations among the 21-gene RS, chemotherapy decision-making and prognosis were analyzed.

RESULTS

We included 2721 patients in this study. According to TAILORx cutoffs, 352 (12.9%), 1814 (66.7%), and 555 (20.4%) patients were classified as low-, intermediate-, and high-risk cohorts, respectively. The 21-gene RS categories were associated with the probability of receiving chemotherapy, with 7.1%, 33.4%, and 77.1% of patients in low-, intermediate-, and high-risk cohorts treated with chemotherapy, respectively (P < 0.001). Those in the intermediate-risk cohort were significantly less likely to receive chemotherapy over time (P = 0.008), and the trends of chemotherapy receipt were stable in the low-risk and high-risk cohorts over time. Multivariate analysis showed that the 21-gene RS was an independent prognostic indicator for breast cancer specific survival. In the stratified analysis, the receipt of chemotherapy was associated with better breast cancer specific survival in the high-risk cohort (P = 0.028), but not in the intermediate-risk cohort (P = 0.223).

CONCLUSIONS

21-gene RS has clinical implications for young breast cancer patients with respect to optimizing chemotherapy-decisions. Despite increasing rates of chemotherapy receipt in young patients, more studies are needed to determine the definitive effect of chemotherapy in young patients with three RS categories.

Prognostic Impact of the 21-Gene Recurrence Score Assay Among Young Women With Node-Negative and Node-Positive ER-Positive/HER2-Negative Breast Cancer

PURPOSE

The 21-gene recurrence score (RS) assay is prognostic among women with early-stage estrogen receptor-positive (ER+) and human epidermal growth factor receptor 2-negative (HER2-) breast cancer and is used to inform recommendations for chemotherapy. Women ≤ 40 years of age represent a minority of patients studied using gene expression profiles.

METHODS

The Young Women's Breast Cancer Study is a prospective cohort of women diagnosed with breast cancer at age ≤ 40 years and enrolled patients between 2006 and 2016 (N = 1,302). We identified patients with stage I-III ER+/HER2- breast cancer. The RS assay was performed on banked specimens for patients who had not been tested clinically. Distant recurrence-free survival (DRFS) was assessed by TAILORx and traditional RS risk groups among patients with axillary node-negative (N0) and limited node-positive (N1) breast cancer.

RESULTS

Among eligible women (N = 577), 189 (33%) had undergone RS testing, and 320 (56%) had banked specimens sufficient for testing. Median follow-up was 6.0 years. Median age at diagnosis was 37.2 years; 300 of 509 patients (59%) had N0 breast cancer, of whom 195 (65%) had an RS of 11-25 and fewer than half (86 of 195; 44%) received chemotherapy. Six-year DRFS rates were 94.4% and 92.3% (RS < 11), 96.9% and 85.2% (RS 11-25), and 85.1% and 71.3% (RS ≥ 26) among women with N0 and N1 disease, respectively.

CONCLUSION

The RS assay is prognostic among young women with node-negative and limited node-positive breast cancer, representing a valuable tool for risk stratification. Disease outcomes with a median follow-up of 6 years among young women with N0 disease and an RS of 0-25, a minority of whom received chemotherapy, and node-positive disease with an RS < 11 were very good, whereas those with N0 disease and an RS ≥ 26 or N1 disease with an RS ≥ 11 experienced substantial risk of early distant recurrence.

LobSig is a multigene predictor of outcome in invasive lobular carcinoma

Invasive lobular carcinoma (ILC) is the most common special type of breast cancer, and is characterized by functional loss of E-cadherin, resulting in cellular adhesion defects. ILC typically present as estrogen receptor positive, grade 2 breast cancers, with a good short-term prognosis. Several large-scale molecular profiling studies have now dissected the unique genomics of ILC. We have undertaken an integrative analysis of gene expression and DNA copy number to identify novel drivers and prognostic biomarkers, using in-house (n = 25), METABRIC (n = 125) and TCGA (n = 146) samples. Using in silico integrative analyses, a 194-gene set was derived that is highly prognostic in ILC (P = 1.20 × 10-5)-we named this metagene 'LobSig'. Assessing a 10-year follow-up period, LobSig outperformed the Nottingham Prognostic Index, PAM50 risk-of-recurrence (Prosigna), OncotypeDx, and Genomic Grade Index (MapQuantDx) in a stepwise, multivariate Cox proportional hazards model, particularly in grade 2 ILC cases (χ 2, P = 9.0 × 10-6), which are difficult to prognosticate clinically. Importantly, LobSig status predicted outcome with 94.6% accuracy amongst cases classified as 'moderate-risk' according to Nottingham Prognostic Index in the METABRIC cohort. Network analysis identified few candidate pathways, though genesets related to proliferation were identified, and a LobSig-high phenotype was associated with the TCGA proliferative subtype (χ 2, P < 8.86 × 10-4). ILC with a poor outcome as predicted by LobSig were enriched with mutations in ERBB2, ERBB3, TP53, AKT1 and ROS1. LobSig has the potential to be a clinically relevant prognostic signature and warrants further development.

Female breast cancers (T1-2, N0, M0, HR+, HER2-) with an intermediate genetic-based recurrence risk: a real-world estimate in Italy

OBJECTIVES

Prognostic definition and treatment of breast cancer are supported by multigene testing. A recent trial (TAILORx) provided evidence against the use of adjuvant chemotherapy in early breast cancer (HR+ HER2-) with an intermediate result (11-25) in a multigene test (Oncotype DX). These results consequently fueled great discussion among oncologists. We aimed to estimate the burden of Italian incident breast cancer patients who, each year, may be involved in such decision-making.

METHODS

We used the data collected in the Romagna Cancer Registry to estimate the number of cases with the inclusion criteria of the TAILORx trial. Adjustments based on geographical variability in breast cancer incidence in Italy were applied to national estimates. Cases were estimated by Oncotype DX recurrence risk groups: ⩽10, 11-25, ⩾26. We also estimated the proportion of grade 1, 2, or 3 disease among breast cancer cases.

RESULTS

An overall 52,300 breast cancer cases were estimated to be diagnosed in Italy in 2018. Of these, 18,225 fit the TAILORx inclusion criteria: 3,025 were expected to have a low risk of recurrence (⩽10), 11,536 (63.3% of all cases) an intermediate risk (11-25), and 3,664 a high risk (⩾26). Among the group at intermediate risk, who may benefit from less aggressive therapy, 2,414 were estimated to have grade 1 disease, 7,618 grade 2, and 1,983 grade 3.

CONCLUSIONS

This article provides reliable estimates on the burden of Italian women with breast cancer who, once tested with multigene testing, could potentially have their treatment changed to hormone therapy only.

21-gene recurrence score and adjuvant chemotherapy decisions in patients with invasive lobular breast cancer

Aim: To determine the effect of the 21-gene recurrence score (RS) on outcome and chemotherapy decision in breast invasive lobular carcinoma (ILC). Materials & methods: We included 6467 patients with early stage and estrogen receptor–positive ILC from the Surveillance, epidemiology, and end results database. Results: A total of 9.1, 31.4, and 70.1% of patients with low-, intermediate-, and high-risk RS groups received chemotherapy, respectively. A higher RS was independently associated with poor breast cancer-specific survival, and receipt of chemotherapy was not related to better breast cancer-specific survival in low-, intermediate-, or high-risk RS groups. Conclusion: The 21-gene RS could impact chemotherapy decision making in early-stage ILC. However, adjuvant chemotherapy does not appear to improve outcome in high-risk RS cohort.

21-Gene Recurrence Score Testing in HER2-positive Patients

INTRODUCTION

The 21-gene recurrence score (RS) has been extensively studied and validated in patients with estrogen receptor-positive (ER⁺), human epidermal growth factor 2 (HER2)-negative breast cancer; however, RS testing is not routinely performed in patients with HER2-positive (HER2⁺) disease. We sought to determine patterns of RS testing, to characterize RS distributions, and to determine the impact of RS results on clinical decision-making for patients with ER⁺, HER2⁺ breast cancer.

MATERIALS AND METHODS

Using the Surveillance and Epidemiology End Results program database, we identified women with ER⁺, HER2⁺ breast cancer. We stratified patients using TAILORx RS cutoffs and evaluated treatment characteristics across patients. Multivariable logistic regression was performed to determine factors associated with RS testing and receipt of a high-risk RS.

RESULTS

Overall, 5% of patients with ER⁺, HER2⁺, early stage breast cancer underwent RS testing. The distribution of RS testing by TAILORx cutoffs were: high-risk, 17%; intermediate-risk, 49%; and low-risk, 34%. Chemotherapy utilization among those not tested was 66%. Among those tested, utilization was significantly associated with RS results: 67% of high-risk, 30% of intermediate-risk, and 19% of low-risk patients received chemotherapy. Progesterone receptor-negative status, larger tumor size, and high tumor grade were significantly associated with high-risk RS.

CONCLUSIONS

RS testing is used sparingly among patients with HER2⁺ early-stage breast cancer; however, test results appear to impact clinician's decision-making on chemotherapy use.

The Distribution and Outcomes of the 21-Gene Recurrence Score in T1-T2N0 Estrogen Receptor-Positive Breast Cancer With Different Histologic Subtypes

Background: The clinical value of 21-gene recurrence score (RS) in various breast cancer histologic subtypes is not well established.

Aims: To assess the distribution and outcomes of the 21-gene RS among various T1-T2N0 estrogen receptor-positive breast cancer histologic subtypes.

Methods: Using the Surveillance, Epidemiology and End Results database, we investigated the distribution and outcomes of the 21-gene RS among various breast cancer histologic subtypes between 2004 and 2015. The histologic subtypes with 200 or more cases were further analyzed.

Results: We identified 83,665 patients including eight histologic subtypes. The most common subtype was invasive ductal carcinoma not otherwise specified (IDC NOS) (77.9%), followed by lobular carcinoma NOS, mixed infiltrating duct and lobular carcinoma (IDC-L), mucinous adenocarcinoma, tubular adenocarcinoma, micropapillary ductal carcinoma, cribriform carcinoma NOS, and intraductal papillary adenocarcinoma with invasion with 10.8, 7.7, 2.1, 0.6, 0.3, 0.2, and 0.2%, respectively. The 5-years breast cancer specific survival (BCSS) was 98.8, 98.8, 98.9, 99.6, 100, 100, 100, and 100%, respectively (P = 0.011). Patients with IDC NOS (8.9%), micropapillary ductal carcinoma (8.8%), and intraductal papillary adenocarcinoma with invasion (8.2%) had significantly higher percentage of high-risk RS compared to other histologic subtypes (1.0–3.8%) (P < 0.001). The mean RS was higher in IDC NOS, lobular carcinoma NOS, and IDC-L compared to other subtypes. In multivariate analysis, 21-gene RS was the independent prognostic factor in patients with IDC NOS (P < 0.001), lobular carcinoma NOS (P < 0.001), and IDC-L (P < 0.001), patients with a higher RS was associated with poor BCSS.

Conclusion: Our results demonstrate that there is a significant difference in distribution of 21-gene RS in T1-T2N0 estrogen receptor-positive breast cancer with different histologic subtypes. Long-term studies with larger series are needed to confirm the role of the 21-gene RS array in prognosis assessment and chemotherapy decision-making in special histologic subtypes with favorable prognosis.

Predictors for Survival and Distribution of 21-Gene Recurrence Score in Patients With Pure Mucinous Breast Cancer: A SEER Population-Based Retrospective Analysis

BACKGROUND

Pure mucinous breast cancer (PMBC) is a rare pathologic type of breast cancer, the prognostic factors of which have not been clearly defined. This study aimed to analyze the prognostic markers and distribution of 21-gene recurrence score (RS) in patients with PMBC.

PATIENTS AND METHODS

Utilizing the Surveillance, Epidemiology, and End Results (SEER) database, a retrospective analysis of PMBC cases was conducted. Multivariate analyses were used to evaluate the indicators for prognosis and the correlations between RS and traditional clinicopathologic characteristics. Disease was subdivided into 4 molecular phenotypes using estrogen receptor (ER) status and tumor grade.

RESULTS

Of the 8048 patients, most had ER-positive and node-negative tumors. Multivariate analysis revealed that molecular phenotype as well as age, race, tumor size, and lymph node status was an independent prognostic factor for patients with PMBC (P < .05). The 5-year breast cancer-specific survival of patients among different phenotypes was significantly different (97.9% for ER-positive and grade I tumor, 96.9% for ER-positive and grade II-III tumor, 96% for ER-negative and grade I tumor, 90.1% for ER-negative and grade II-III tumors, P < .001). The proportions of patients categorized into low, intermediate, and high RS risk group were 64.9%, 31.9%, and 3.2%, respectively. Grade, progesterone receptor status, and age were identified as independent variables associated with RS.

CONCLUSION

PMBC had favorable biological features and relatively good prognosis. Molecular phenotype as well as age, race, tumor size, and lymph node status were independent prognostic markers. Furthermore, age, progesterone receptor status, and grade could independently predict RS.