Nomogram Update to Predict the High Genomic Risk Breast Cancer by Different Races

PURPOSE

To develop a nomogram to predict the high-risk recurrence score (RS) and to customize the nomogram for different races in early-stage hormone receptor (HoR)-positive, human epidermal growth factor receptor-2 (HER2)-negative breast cancer.

METHODS

Patients diagnosed between 2010 and 2015 were included from the surveillance, epidemiology, and end results oncotype DX database. The nomogram was assessed with a receiver operating characteristic curve to measure the area under the curve (AUC) with a 95% confidence interval (95% CI). The nomogram was developed and internally validated for discrimination and calibration, and then validated in different races.

RESULTS

A total of 48,464 patients were included and randomly assigned to the training cohort (n = 36370, 75.0%) and validation cohort (n = 12,094, 25.0%). Patients in the training cohort were identified to develop the nomogram, including 32,683 (89.9%) White women, 3135 (8.6%) Black women, and 552 (1.5%) Chinese women. Five independent predictive factors for high-risk RS were included to develop the nomogram, including tumor grade, progesterone receptor status, histological subtype, race, and tumor stage. The AUC was 0.696 (95% CI, 0.682-0.710) in the training cohort and 0.700 (95% CI, 0.676-0.724) in the validation cohort. There was no significant difference between the training cohort and the validation cohort. When validating the nomogram classified by race, the AUC was 0.694 (95% CI, 0.682-0.706) for the White cohort, 0.708 (95% CI, 0.673-0.743) for the Black cohort, and 0.653 (95% CI, 0.565-0.741) for the Chinese cohort.

CONCLUSION

The developed nomogram for predicting high-risk RS is available for different races in patients with HoR+/HER2- breast cancer, which could be used as qualified surrogates before ordering the 21-gene RS testing.

Association of tumor immune microenvironment profiling and 21-gene recurrence assay in early breast cancer patients

INTRODUCTION

Tumor immune microenvironment (TIME) plays a vital role in breast cancer development, treatment resistance, and prognosis. This study evaluates the association of TIME profiling and 21-gene recurrence score (RS) in early Luminal breast cancer patients.

METHODS

ER+ /HER2-, pN0 breast cancer patients with available RS results who received surgery between January 2009 and December 2013 were enrolled. TIME markers, including stromal tumor infiltrating lymphocytes (TILs), CD3, CD4, CD8, and tumor PD-L1 expression, were comprehensively analyzed. Association of TIME markers with RS, as well as their correlation with breast cancer-specific survival (BCSS) were tested.

RESULTS

Overall, 385 patients were included, of whom 341 (88.6%) had TILs ≤10%. TIME markers were positively but moderately correlated with each other (Spearman r 0.28-0.53, all P < 0.05). Continuous RS showed a weak correlation with continuous TILs, CD3, CD8, and PD-L1. Regarding single gene mRNA level in the 21-gene RS panel, higher expression of TIME markers was related to lower ER group genes expression, but higher proliferation and invasion group genes level. After a median follow-up of 91.67 (range 5.03-134.03) months, TILs (P = 0.049) and PD-L1 (P = 0.034) were inversely associated with BCSS.

CONCLUSIONS

Breast cancer TIME markers, including TILs, CD3, CD4, CD8, and PD-L1, were correlated with 21-gene RS score. Lower expression of ER group genes, as well as higher expression of proliferation and invasion group genes were associated with a higher level of these TIME markers, warranting further exploration.

Adjuvant chemotherapy in patients with invasive lobular carcinoma and use of the 21-gene recurrence score: A National Cancer Database analysis

BACKGROUND

Invasive lobular carcinoma (ILC) is traditionally considered less responsive to chemotherapy. Although the Oncotype recurrence score (RS) has been validated to identify high-risk patients who benefit from chemotherapy, some studies have questioned its relevance in patients with ILC. The objective of this study was to better characterize potential use of the RS in these patients.

METHODS

The National Cancer Database was used to identify women with stage I through III, T1 through T3, N0 or N1, hormone receptor-positive, HER2-negative ILC or invasive ductal carcinoma (IDC) who had an available RS between 2010 and 2016. Multivariable Cox regression was used to model the effect of variables on 5-year overall survival (OS). The Kaplan-Meier method was used to estimate OS according to the RS, nodal status, and chemotherapy.

RESULTS

In total, 15,763 patients with ILC and 100,070 with IDC were identified. The mean age of patients with ILC and IDC was 59.2 ± 9.1 and 57.2 ± 9.8, respectively. A lower percentage of patients with ILC versus those with IDC had a high RS, defined as >25 (6.6% vs 16.0%; P < .0001). ILC patients with a high RS who had N0 or N1 disease received approximately 10% less chemotherapy compared with similar patients who had IDC. The results indicated that the RS had statistically significant prognostic value for patients with ILC. In addition, an absolute OS advantage was correlated with the receipt of chemotherapy by patients with ILC who had a high RS with N0 or N1 disease.

CONCLUSIONS

Patients with ILC who have a high RS are treated less often with chemotherapy compared with similar patients who have IDC. Nevertheless, the RS has a prognostic as well as a predictive value in ILC, with an association between OS benefit and chemotherapy receipt in patients who have ILC with a high RS, especially if they have N1 disease.

LAY SUMMARY

Invasive lobular carcinoma (ILC) is a subtype of breast cancer comprising about 15% of cases. The Oncotype recurrence score (RS) is a genetic test of breast tumors that helps predict which patients might benefit from chemotherapy. Some have doubted the relevance of the RS for patients with ILC. In this study, the authors show that the RS is relevant for patients who have ILC. The RS has the potential of predicting the risk of recurrence and identifying patients with ILC who might benefit from chemotherapy.

Distribution and influence of the 21-gene recurrence score on chemotherapy decision-making in special type of breast cancer

The 21-gene recurrence score (RS) testing could guide treatment for luminal breast cancer with the histological non-special type (NST). However, there is limited data on its role in invasive lobular carcinoma (ILC) or other special types (ST). In the current study, we retrospectively included patients with the 21-gene RS testing between Jan. 2009 and Dec. 2017 and compared the RS distribution as well as gene expression levels among NST, ILC, and other ST with favorable prognosis. Adjuvant chemotherapy usage, clinical outcomes, and decision-making change due to RS testing were also analyzed. A total of 1736 patients were included: 1511 (87.0%) patients with NST, 79 (4.6%) with ILC, and 146 (8.4%) with ST. The median RS was 25 and 25 in the NST and ILC groups, which was 22 in the ST group (P=0.001). Compared with NST, ILC had almost similar expression of the cancer-related genes, while ST had lower expression of genes involved in the proliferation group. The rate of adjuvant chemotherapy usage was 6.7%, 38.1%, and 54.5% for ILC patients, and was 7.1%, 15.8%, and 17.8% for ST patients in the low- (RS<18), intermediate- (RS18-30), and high-risk (RS>30) RS groups, both of which were lower than that for NST patients. RS was associated with chemotherapy usage in NST patients but not in ILC or ST patients by multivariant analysis. After the testing, 20.5% of patients with NST had changes in chemotherapy decision-making, which is 21.5% in ILC patients and 16.4% in ST patients (P=0.490). Furthermore, the prognostic value of RS was only observed in NST cohort but not in ILC or ST patients. In conclusion, ST had lower RS than NST and ILC, which were mainly due to the lower expression of genes in the proliferation group. The 21-gene RS results were associated with chemotherapy usage in the NST groups, while its role in ILC and ST patients deserve to be further studied.

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

Simple Summary

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

Abstract

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

Efficacy of adjuvant chemotherapy stratified by age and the 21-gene recurrence score in estrogen receptor-positive breast cancer

BACKGROUND

The 21-gene recurrence score (RS) can predict chemotherapy benefit in estrogen receptor-positive, human epidermal growth factor receptor-2-negative (ER+/HER2-) early breast cancer patients. Age would influence the interaction between RS and chemotherapy effect. The current study aimed to determine RS thresholds which were predictive of chemotherapy benefit in young and old women, respectively.

METHODS

Patients diagnosed with pN0-1, ER+/HER2- breast cancer between 2009 and 2016 were retrospectively reviewed. Propensity score matching was performed according to chemotherapy usage. After stratifying patients with different cutoffs of age, the RS threshold indicating chemotherapy benefit in each age strata were determined by cox proportional hazard models.

RESULTS

A total of 1227 patients were included. The median age was 58 years and the median RS was 24. After matching, the RS thresholds suggesting chemotherapy benefit varied with age. For patients ≤55 years, chemotherapy benefit was observed in those having RS > 25 (P = 0.03), with 4-year invasive disease-free survival (IDFS) of 97.0 and 89.3% in patients receiving chemotherapy or not. While patients derived no benefit from chemotherapy if they had RS ≤25 (P = 0.66, 4-year IDFS: 95.3% vs. 94.6%). For patients > 55 years, adjuvant chemotherapy was associated with better prognosis in those with RS > 36 (P = 0.014, 4-year IDFS: 94.7% vs. 76.2%), but not in those having RS ≤36 (P = 0.13, 4-year IDFS: 92.3% vs. 95.8%).

CONCLUSIONS

Old patients need higher RS thresholds to demonstrate the chemotherapy benefit. Further efforts are warranted to investigate the association between age and predictive RS thresholds.

Prognostic value of the 21-gene recurrence score for regional recurrence in patients with estrogen receptor-positive breast cancer

PURPOSE

To evaluate the prognostic value of the 21-gene recurrence score (RS) for regional recurrence (RR) in patients with estrogen receptor-positive breast cancer.

METHODS

We reviewed the medical records of 446 patients who underwent 21-gene RS assay after breast-conserving surgery or mastectomy. The high-RS group was defined as patients who were (1) older than 50 years with an RS of 26 or higher, or (2) 50 years or younger with an RS of 16 or higher.

RESULTS

The 5-year rates of local recurrence (LR), RR, and distant metastasis (DM) were 2.2%, 2.7%, and 4.7%, respectively. The 5-year overall survival (OS) rate was 99.1%. Of the patients, 269 (60.3%) had low-RS, while 177 (39.7%) had high-RS. The 5-year OS rate of the high-RS group was significantly lower than that of the low-RS. The 5-year rates of RR and DM in the high-RS group were significantly higher than those in the low-RS group, while the LR rates did not differ significantly. In multivariable analysis, the high-RS group had a significant relationship with increased RR rate (p = 0.037). Patients who had both high-RS and clinical high-risk features had a significantly higher 5-year RR rate (7.9%) compared with other groups.

CONCLUSIONS

High-RS was an independent risk factor for RR. The significantly higher RR rate of patients with both high-RS and clinical high-risk features compared with other groups suggests that this patient group can be a potential candidate for regional nodal irradiation.

Genomic expression assay testing among American Indian and Alaska Native women with breast cancer

BACKGROUND

Breast cancer is one of the most common causes of cancer mortality for all women, including American Indian and Alaska Native (AI/AN) women. The use of the 21-gene recurrence score (RS) appears to be predictive of the benefit of chemotherapy for women with estrogen receptor (ER)-positive breast cancer. The objective of the current study was to compare RS testing between AI/AN and non-Hispanic White (NHW) women with breast cancer.

METHODS

The Surveillance, Epidemiology, and End Results program was used to identify women with ER-positive breast cancer from 2004 through 2015. Multivariable logistic regression was used to evaluate factors associated with RS use, with high-risk RS, and with chemotherapy use among those with a high-risk RS.

RESULTS

A total of 363,387 NHW patients and 1951 AI/AN patients with ER-positive breast cancer were identified. AI/AN women were found to be less likely to undergo RS testing and, when tested, were more likely to have a high-risk RS. In the multivariable logistic regression analysis, AI/AN women were found to be significantly more likely to have a high-risk RS (odds ratio,1.28; 95% confidence interval, 1.01-1.66). Among untested women, chemotherapy use was higher for AI/AN women; however, the use of chemotherapy was not found to be significantly different between the groups with a high-risk RS. Using Cox proportional hazards models, AI/AN race was found to be significantly associated with worse overall survival.

CONCLUSIONS

AI/AN women were less likely to undergo RS testing compared with NHW women and were more likely to have a high-risk RS. Reversing the disparity in genomic expression assay testing is critical to ensure guideline-based breast cancer treatment and improve survival rates for AI/AN women with breast cancer.

Clinicopathological characteristics, adjuvant chemotherapy decision and disease outcome in patients with breast cancer with a 21-gene recurrence score of 26-30

Recurrence score (RS) could be used to predict clinical outcomes and chemotherapy efficacy in patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative and lymph node-negative breast cancer. However, the clinical features and management of patients with an RS of 26–30 are not completely understood. In the present study, 783 patients with HR⁺/HER2⁻, lymph node-negative early breast cancer and RS ≥18 were included and categorized into RS=18−25 (47.8%), 26–30 (25.5%) or ≥31 (26.7%) groups. Clinicopathological characteristics, adjuvant chemotherapy usage and disease outcomes were compared. Alterations in the adjuvant chemotherapy recommendation after 21-gene RS testing were also analyzed. The results indicated that patients with RS=26−30 had higher progesterone receptor (PR) expression [odds ratio (OR)=2.84; P<0.001] and lower Ki-67 index (OR, 1.88; P=0.032) compared with patients with RS ≥31. Multivariate analysis demonstrated that age ≤50 years (OR, 5.75; P=0.001) and luminal-B subtype (OR, 7.75; P<0.001) were factors that were independently associated with chemotherapy usage in the RS=26−30 group. Among 104 patients who were not recommended chemotherapy before 21-gene RS testing, the treatment decision for 52 patients was changed to recommend chemotherapy once an RS of 26–30 was identified. The patient adherence rate to the treatment recommendation was 95.0% (190/200). After a median follow-up of 21.5 months, 6 patients displayed disease recurrence in the RS=26−30 group, and there was no significant difference between patients receiving chemotherapy and patients not receiving chemotherapy. In conclusion, patients with RS=26−30 had tumors with higher PR expression and lower Ki-67 index compared with those of patients with RS ≥31. Age, luminal subtype and RS testing influenced chemotherapy usage in patients with RS=26−30; however, no significant benefit from adjuvant chemotherapy was observed in a short term of 2 years.

Do 21-Gene Recurrence Score Influence Chemotherapy Decisions in T1bN0 Breast Cancer Patients?

Purpose: Hormone receptor (HR)-positive breast cancer patients with tumor size ≤1.0 cm and negative node have favorable outcomes. The 21-gene Recurrence Score (RS) could predict response to chemotherapy for HR+ breast cancer, but its role in T1bN0 disease is challenging.

Methods: T1bN0 breast cancer patients diagnosed between January 2014 and June 2019 with RS results were included and categorized as Low- (RS < 18), Intermediate- (RS 18–30), or High-risk (RS > 30) groups. Univariate and multivariate analysis were used to assess factors associated with RS distribution and chemotherapy recommendation. Chemotherapy decisions change and patient adherence after 21-gene RS testing were also evaluated.

Results: Among 237 patients with T1bN0 tumors, proportions of Low-, Intermediate-, and High-risk RS were 19.8, 63.3, and 16.9%, respectively. Multivariate analysis found that ER expression (P = 0.011), PR expression (P < 0.001), and Ki-67 index (P = 0.001) were independently associated with RS distribution. Adjuvant chemotherapy was recommended for 31.6% of patients, which was more frequently given to patients with higher tumor grade [Odds ratio (OR) = 2.99 for grade II, OR = 59.19 for grade III, P = 0.006], lymph vascular invasion (OR = 8.22, P = 0.032), Luminal-B subtype (OR = 5.68, P < 0.001), and Intermediate-to High-risk RS (OR = 10.01 for Intermediate-risk, OR = 192.42 for High-risk, P < 0.001). Chemotherapy decision change was found in 18.6% of patients, mainly in those with Intermediate- to High-risk RS tumor with the majority from no-chemotherapy to chemotherapy. The treatment compliance rate after the 21-gene RS testing with MDT was 95.4%.

Conclusion: RS category was related to ER, PR, and Ki-67 expression, which was recognized as an independent factor of chemotherapy recommendation in T1bN0 breast cancer. The 21-gene RS testing would lead to a chemotherapy decision change rate of 18.6% as well as a high treatment adherence, which can be applied in T1bN0 patients.

The prognostic and predictive role of 21-gene recurrence scores in hormone receptor-positive early-stage breast cancer

Over the past two decades, gene expression profiling of breast cancer has emerged as an important tool in early-stage breast cancer management. The approach provides important information on underlying biological mechanisms, breast cancer classification, future risk potential of developing recurrent metastatic disease, and provides beneficial clues for adjuvant chemotherapy in hormone receptor (HR) positive breast cancer. Of the commercially available genomic tests for breast cancer, the prognostic and predictive value of 21-gene recurrence score tests have been validated using both retrospective data and prospective clinical trials. In this paper, we reviewed the current evidence on 21-gene expression profiles for HR-positive HER2-negative early-stage breast cancer management. We show that current evidence supports endocrine therapy alone as an appropriate adjuvant systemic therapy for approximately 70% of women with HR-positive, HER2-negative, node-negative breast cancer. Evolving evidence also suggests that 21-gene recurrence scores have predictive values for node-positive breast cancer and that chemotherapy can be avoided in more than half of women with nodes 1 to 3 positive HR-positive breast cancer. Furthermore, retrospective data also supports the predictive role of 21-gene recurrence scores for adjuvant radiation therapy. A prospective trial in this area is ongoing.

Decision-making of Adjuvant Chemotherapy for Breast Cancer Patients with Discordant Risk Classifications between Clinical-Pathological Factors and 21-gene Recurrence Score

Background: Clinical-pathological factors and 21-gene recurrence score (RS) influence adjuvant chemotherapy (ACT) decision for early breast cancer patients. We investigated the decision-making of ACT in patients with discordant risk classifications of clinical-pathological factors and RS.

Methods: Patients with hormonal receptor (HR)+/ human epidermal growth factor receptor 2 (HER2)-, early breast cancer, who underwent 21-gene RS testing were identified from Ruijin Hospital (RJBC) and the Surveillance, Epidemiology, and End Results (SEER) database. According to Adjuvant! Online and RS (≤25 or >25), discordant risk classifications were defined as: clinical low-risk/ RS high-risk (C-low/ RS-high) and clinical high-risk/ RS low-risk (C-high/RS-low). McNemar's test was used to assess the changes between pre- and post-RS recommendations. Breast cancer-specific survival (BCSS) was estimated using the Kaplan-Meier methods.

Results: Among 727 RJBC patients, the C-low/RS-high group and the C-high/RS-low group represented 19.7% and 21.3% of the cohort. After receiving 21-gene RS results, treatment recommendations were changed for 22.1% patients with discordant risk classifications: ACT rate increased from 41.9% to 75.5% in the C-low/RS-high group and decreased from 63.9% to 60.0% in the C-high/RS-low group. Among 2958 patients from the SEER cohort, 18.4% of the C-high/RS-low group and 59.2% of the C-low/RS-high group received ACT. There was no significant difference in the estimated 3-year BCSS between ACT or not among the C-low/RS-high group (p=0.708) and the C-high/RS-low groups (p=0.391).

Conclusion: For patients with discordant risk classifications, physicians were apt to adopt the 21-gene RS rather than routine clinical-pathological factors to guide ACT selection.

Adjuvant chemotherapy and survival among patients 70 years of age and younger with node-negative breast cancer and the 21-gene recurrence score of 26-30

Background

The benefits of chemotherapy in node-negative, hormone receptor-positive, and human epidermal growth factor receptor 2 (HER2)-negative breast cancer patients with the 21-gene recurrence score (RS) of 18–30, particularly those with RS 26–30, are not known.

Methods

Using the Surveillance, Epidemiology, and End Results (SEER) data, we retrospectively identified 29,137 breast cancer patients with the 21-gene RS of 18–30 diagnosed between 2004 and 2015. Mortality risks according to the RS and chemotherapy use were compared by the Kaplan-Meier method and Cox’s proportional hazards model.

Results

Among the breast cancer patients with the RS 18–30, 21% of them had RS 26–30. Compared to breast cancer patients with RS 18–25, patients with RS 26–30 had more aggressive tumor characteristics and chemotherapy use and increased risk of breast cancer-specific mortality and overall mortality. In breast cancer patients who were aged ≤ 70 years and had RS of 26–30, chemotherapy administration was associated with a 32% lower risk of breast cancer-specific mortality (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.47–0.99) and a 42% lower risk of overall mortality (HR, 0.58; 95% CI, 0.44–0.76). Survival benefits were most pronounced in breast cancer patients who were younger or had grade III tumor.

Conclusions

The 21-gene RS of 18–30 showed heterogeneous outcomes, and the RS 26–30 was a significant prognostic factor for an increased risk of mortality. Adjuvant chemotherapy could improve the survival of node-negative, hormone receptor-positive, and HER2-negative breast cancer patients with the 21-gene RS 26–30 and should be considered for patients, especially younger patients or patients with high-grade tumors.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1190-4) contains supplementary material, which is available to authorized users.

Clinical analysis of 21-gene recurrence score test in hormone receptor-positive early-stage breast cancer

The 21-gene recurrence score (RS) predicts the prognosis of patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative early-stage breast cancer and the effectiveness of adding adjuvant chemotherapy on the basis of endocrine therapy to avoid excessive chemotherapy. The present study aimed to analyze clinicopathological characteristics and chemotherapeutic efficacy-related target genes with the 21-gene RS in hormone receptor-positive early-stage breast cancer in China. The prognostic value of chemotherapeutic efficacy-related target genes was also examined. In addition, this study investigated the postoperative adjuvant therapeutic decision-oriented role of 21-gene RS in hormone receptor-positive and lymph node-negative early-stage breast cancer. In the present retrospective study, 110 ER⁺/HER2⁻ early-stage breast cancer patients were tested with the 21-gene RS. The analyses of clinicopathological characteristics and chemotherapeutic efficacy-related target genes with the 21-gene RS were performed using the χ² test, the Wilcoxon rank-sum test and binary logistic regression. Kaplan-Meier survival plots were drawn in www.kmplot.com. Furthermore, the McNemar χ² test was used to compare the changes of treatment decisions before and after the 21-gene test. The median RS of 110 patients was 16 (range, 2–47), and patients were categorized as low (59.1%), intermediate (34.5%) or high risk (6.4%). The results revealed that higher body mass index, invasive ductal carcinoma type, higher histological grade, luminal B molecular type and higher thymidylate synthetase (TYMS) and DNA topoisomerase IIα (TOP2A) gene expression levels were more likely to have a higher RS. Kaplan-Meier plots suggested that expression of TYMS, tubulin β3 class III (TUBB3) and TOP2A genes was significantly associated with relapse-free survival for ER⁺ breast cancer. Additionally, prior to 21-gene RS testing, 61 patients (55%) were recommended adjuvant chemotherapy and endocrine therapy; however, following 21-gene test, 32 patients (29%) were treated with only adjuvant endocrine therapy. TYMS, TUBB3 and TOP2A gene expression may have prognostic value for ER⁺ breast cancer. In addition, 21-gene RS testing may aid to avoid excessive postoperative adjuvant chemotherapy.

21-Gene Recurrence Score Assay and Outcomes of Adjuvant Radiotherapy in Elderly Women With Early-Stage Breast Cancer After Breast-Conserving Surgery

Introduction: To assess the role of the 21-gene recurrence score (RS) assay on decision-making of postoperative radiotherapy (RT) following breast-conserving surgery (BCS) in elderly women with early-stage breast cancer. Methods: The 21-gene RS for elderly (≥65 years) women with stage T1-2N0M0 estrogen receptor-positive breast cancer who underwent BCS from 2004 to 2015 was obtained from the Surveillance, Epidemiology, and End Results program. We estimated the association of 21-gene RS and adjuvant RT related to breast cancer-specific survival (BCSS) using propensity score matching (PSM). Results: We identified 18,456 patients, of which 15,326 (83.0%) received postoperative RT. Of identified patients, 58.9, 34.0, and 7.1% of patients had a low-, intermediate-, and high-risk RS, respectively. Receipt of postoperative RT was not related to the year of diagnosis according to the 21-gene RS groups. Multivariate analysis suggested that receipt of postoperative RT was an independent predictor of better BCSS before (hazard ratio [HR] 0.587, 95% confidence interval [CI] 0.426-0.809, P = 0.001) and after (HR 0.613, 95%CI 0.390-0.963, P = 0.034) PSM. However, subgroups analyses indicated that receipt of postoperative RT was related to better BCSS in women with intermediate-risk RS before (HR 0.467, 95%CI 0.283-0.772, P = 0.003) and after (HR 0.389, 95%CI 0.179-0.846, P = 0.017) PSM, but not in women with low- and high-risk RS groups before and after PSM. Conclusions: Although causation cannot be implied, adjuvant RT in elderly women was associated with a greater effect size in patients with an intermediate-risk RS.

Comparisons of tumor-infiltrating lymphocyte levels and the 21-gene recurrence score in ER-positive/HER2-negative breast cancer

Background

Recent studies have shown that tumors with extensive tumor-infiltrating lymphocytes (TILs) have a higher probability of pathologic complete response, even in luminal/human epidermal growth factor 2 (HER2)-negative breast cancer. We compared TIL levels and the 21-gene recurrence score (RS) in estrogen receptor (ER)-positive/HER2-negative breast cancer.

Methods

We evaluated the percentage of stromal TILs in 198 ER-positive/HER2-negative patients in whom RS was obtained by examining slides of surgical specimens by standardized methodology proposed by the international TIL Working Group. TIL levels were categorized as high (≥ 60%), intermediate (11–59%), or low (≤ 10%). All tumors were treatment-naïve.

Results

Ninety-seven (49.0%), 88 (44.4%), and 13 patients (6.6%) had low, intermediate, and high TIL levels, respectively. There was a significant but weak correlation between continuous RS and continuous TIL levels (Pearson’s R = 0.201, p = 0.004). The mean RS was significantly highest in high TIL tumors (17.8 ± 10.7 in low TIL tumors, 19.4 ± 8.7 in intermediate TIL tumors, and 26.2 ± 8.2 in high TIL tumors; p = 0.014). However, when we compared categorized RS and TIL levels, we found that tumors with high TIL levels tended to have higher RS (≥ 26) but it was not significant (p = 0.155). Furthermore, multivariate analysis revealed that high RS was not an independent factor associated with high TIL levels. Chemo-endocrine therapy was more frequently performed among patients with high TILs and less frequently among those with low or intermediate TILs (p <  0.001).

Conclusions

Despite of a weak correlation between continuous TIL levels and RS, we found that tumors with high TIL levels tended to have a higher RS in ER-positive/HER2-negative breast cancer. Further study is warranted considering the clinical outcomes.

21-gene recurrence assay in patients receiving intraoperative radiotherapy: are "favorable" characteristics a surrogate for low recurrence?

Background

Intraoperative radiotherapy (IORT) has gained momentum for early stage and favorable breast cancers (BC). The 21-gene recurrence assay guides treatment of hormone positive and node-negative BC.

Methods

Analysis of 82 invasive BC treated with breast conservation surgery (BCS) and IORT 2013-2015. Data collection included patient demographics, tumor characteristics, nodal status, recurrence test (RS) and adjuvant therapy.

Results

The mean age was 68 years. Tumors were stage Ia (86.6%), 3.6% Ib and 9.8% IIa. Of 50 patients (61.0%) with RS testing, 72% (n=36) were low risk (RS 0-17), with 28% (n=14) at intermediate risk (RS 18-30). The 39% (n=32) of patients without RS testing, were more likely to have smaller tumors (1.3 vs. 0.9 cm) and age >70 (P<0.05).

Conclusions

Most patients selected for IORT based on clinical features were indeed low risk based on RS. Given the limited long-term clinical outcome and safety data of this technique, additional investigation is needed.

[Effect of 21-gene recurrence score on chemotherapy decisions for patients with estrogen receptor-positive, epidermal growth factor receptor 2-negative and lymph node-negative early stage-breast cancer]

Objective: To investigate the effect of 21-gene recurrence score on adjuvant chemotherapy decisions for patients with estrogen receptor (ER)-positive, epidermal growth factor receptor 2 (HER-2)-negative and lymph node (LN)-negative early stage-breast cancer. Methods: One hundred and forty-eight patients with ER+ , HER-2- and LN- early stage breast cancer were recruited in the Ruijin hospital, Shanghai Jiao Tong University School of Medicine. The 21-gene recurrence score (RS)assay was performed and systemic therapeutic decisions were made before and after knowing the RS results under multidisciplinary discussion. The effects of RS assay and the other influential factors on adjuvant chemotherapy decision were further analyzed. Results: After knowing the RS results, treatment decisions were changed in 26 out of 148 patients(17.6%). Among them, 9 out of 26 patients were not recommended for chemotherapy; 16 of 26 had treatment recommendation changed to chemotherapy, and chemotherapy regimen was changed in the last one patient. Multivariate analysis showed that RS, age and histological grade were independent factors of decision-making for adjuvant chemotherapy. Conclusion: Our results suggest that 21-gene recurrence score significantly influences decision making for adjuvant chemotherapy in patients with ER+ , HER-2- and LN- early stage breast cancer.

The 21-gene recurrence score complements IBTR! Estimates in early-stage, hormone receptor-positive, HER2-normal, lymph node-negative breast cancer

Clinicians have traditionally used clinicopathological (CP) factors to determine locoregional recurrence (LR) risk of breast cancer and have generated the IBTR! nomogram to predict the risk of ipsilateral breast tumor recurrence (IBTR). The 21-gene recurrence score (RS) assay was recently correlated with LR in retrospective studies. The objective of this study was to examine the relationship between the RS and IBTR!. CP characteristics of 308 consecutive patients who underwent RS testing at our institution were examined. IBTR! was used to estimate the risk of 10-year IBTR. Descriptive statistics were used to compare the RS with the estimated IBTR!. Given a low event rate in this cohort, actual IBTR rates were not reported. Most patients had stage I/II (98%) and grade I/II (77%) disease. Median age was 54 years (range, 30–78). Median IBTR! without radiation therapy was 10% (mean, 12% [range, 4-43%]). RS was low (<18), intermediate (18–30), and high (>30) in 52% (n = 160), 40% (n = 123), and 8% (n = 25) patients. Overall, IBTR! did not correlate with RS (P = .77). We saw no correlation between RS and IBTR! in patients with less than (P = .32) or greater than (P = .48) a 10% risk of IBTR. Interestingly, Ki-67 expression correlated with both IBTR! (P = .019) and the RS (P = .002). Further study is warranted to determine if the RS can provide complementary biological information to CP factors in estimating the risk of LR. Prospective studies evaluating this association may potentially allow for individualized treatment decisions.