The Role of Oncotype DX® Recurrence Score in Predicting Axillary Response After Neoadjuvant Chemotherapy in Breast Cancer

Gene Expression Signatures for Guiding Initial Therapy in ER+/HER2- Early Breast Cancer

In triple-negative (TNBC) and human epidermal growth factor receptor 2-positive (HER2+) breast cancer patients, neoadjuvant systemic therapy is the standard recommendation for tumors larger than 2 cm. Monitoring the response to primary systemic therapy allows for the assessment of treatment effects, the need for breast-conserving surgery (BCS), and the achievement of pathological complete responses (pCRs). In estrogen receptor-positive/HER2-negative (ER+/HER2-) breast cancer, the benefit of neoadjuvant strategies is controversial, as they have shown lower tumor downstaging and pCR rates compared to other breast cancers. In recent decades, several gene expression assays have been developed to tailor adjuvant treatments in ER+/HER2- early breast cancer (EBC) to identify the patients that will benefit the most from adjuvant chemotherapy (CT) and those at low risk who could be spared from undergoing CT. It is still a challenge to identify patients who will benefit from neoadjuvant systemic treatment (CT or endocrine therapy (ET)). Here, we review the published data on the most common gene expression signatures (MammaPrint (MP), BluePrint (BP), Oncotype Dx, PAM50, the Breast Cancer Index (BCI), and EndoPredict (EP)) and their ability to predict the response to neoadjuvant treatment, as well as the possibility of using them on core needle biopsies. Additionally, we review the changes in the gene expression signatures after neoadjuvant treatment, and the ongoing clinical trials related to the utility of gene expression signatures in the neoadjuvant setting.

ER + HER2- early-stage breast cancer: association of HER2 expression, tumor characteristics, and outcomes

PURPOSE

To evaluate the association between the HER2 score as provided by the Oncotype DX Recurrence Score (RS) assay, tumor characteristics, and outcomes in early-stage, ER + HER2-negative breast cancer (BC).

METHODS

All women insured by the Clalit Health Services, with early-stage, ER + HER2-negative BC who underwent RS testing between 2008 and 2011 were included. Patient/tumor characteristics and Kaplan-Meier estimates for distant recurrence-free survival (DRFS) and overall survival (OS) were compared by HER2 category, based on the HER2 score provided by the RS assay: lower HER2 score group representing the lower third of the HER2 score range (≤ 8.5); higher HER2 score group representing the upper 2 thirds of the HER2 score range (8.6-10.7).

RESULTS

1535 patients were included (948 node negative, 587 node positive); 330 (21.5%) were categorized as lower HER2 score and 1205 (78.5%) as higher HER2 score. Compared to the higher HER2 score group, the lower score group included a significantly higher proportion of patients with RS ≥ 26 in both node-negative (41% vs. 13.6%, P < .001) and node-positive diseases (36% vs. 19.4%, P < .001). Compared to the higher HER2 score group, the lower score group had significantly lower Oncotype ER and PR scores and lower proportion of lobular disease. Age and tumor size were comparable between the HER2 score groups. Within each RS category, DRFS and OS were not associated with the HER2 score.

CONCLUSION

Lower HER2 score was associated with higher RS results. Further study is desired to elucidate the role and significance of HER2 expression in early-stage, ER + HER2-negative.

Quantitative Biomarkers, Genomic Assays, and Demographics Associated with Breast-Conserving Surgery Following Neoadjuvant Therapy in Early-Stage, Hormone Receptor-Positive, HER-Negative Breast Cancer

BACKGROUND

Given increased neoadjuvant therapy use in early-stage, hormone receptor (HR)-positive/HER2-negative breast cancer, we sought to quantify likelihood of breast-conserving surgery (BCS) after neoadjuvant chemotherapy (NACT) or endocrine therapy (NET) as a function of ER%/PR%/Ki-67%, 21-gene recurrence scores (RS), or 70-gene risk groups.

METHODS

We analyzed the 2010-2020 National Cancer Database. Surgery was categorized as "mastectomy/BCS." Logistic regression was performed. Adjusted odds ratios (AOR) were per 10-unit increase in ER%/PR%/Ki-67%.

RESULTS

Overall, 42.3% underwent BCS after NACT, whereas 64.0% did after NET. Increasing ER% (AOR = 0.96, 95% confidence interval [CI] 0.94-0.97) or PR% (AOR=0.98, 95% CI 0.96-0.99) was associated with lower odds of BCS after NACT. Increasing Ki-67% was associated with greater odds of BCS (AOR = 1.07, 95% CI 1.04-1.10). Breast-conserving surgery rates increased by ~20 percentage points, with Ki-67% ≥15 or RS >20. Patients with a low (43.0%, AOR = 0.50, 95% CI 0.29-0.88) or intermediate (46.4%, AOR = 0.58, 95% CI 0.41-0.81) RS were less likely than patients with a high RS (65.0%) to undergo BCS after NACT. Increasing ER% was associated with higher odds of BCS after NET (AOR = 1.09, 95% CI 1.01-1.17). Breast-conserving surgery rates increased by ~20 percentage points between ER <50% and >80%. In both cohorts, the odds of BCS were similar between 70-gene low-risk and high-risk groups. Asian or uninsured patients had lower odds of BCS.

CONCLUSIONS

Neoadjuvant chemotherapy is unlikely to downstage tumors with a low-intermediate RS, higher ER%/PR%, or lower Ki-67%. Breast-conserving surgery after NET was most dependent on ER%. Findings could facilitate treatment decision-making based on tumor biology and racial/socioeconomic disparities and improve patient counseling on the likelihood of successful BCS.

The Role of the NOLUS Score in Predicting pCR and iDFS in HR-positive HER2-negative Early Breast Cancer Patients who Received Neoadjuvant Chemotherapy

Background/Aim

Breast cancer remains a significant health challenge, with neoadjuvant chemotherapy (NACT) improving clinical outcomes in certain subtypes. However, the role of NACT in hormone receptor-positive, HER2-negative (HR+/HER2-) breast cancer is unclear due to various outcomes and generally low rates of pathologic complete response (pCR). This study introduces the Non-Luminal Disease Score (NOLUS) as a potential predictive tool for assessing the response to NACT in these cases.

Patients and Methods

We retrospectively assessed patients diagnosed with locally advanced HR+/HER2- breast cancer who received NACT at our institution from 2009 to 2023. The study explored the association between NOLUS and pCR rates. NOLUS was calculated as positive or negative based on the percentage of estrogen receptor, progesterone receptor, and Ki-67 in tumor cells. We also investigated the correlation between pCR and invasive disease-free survival (iDFS), and examined NOLUS positivity across different age groups.

Results

A total of 149 patients met the inclusion criteria. NOLUS-positive patients exhibited a significantly higher pCR rate of 33.33% compared to 10.4% in NOLUS-negative patients (p=0.0031). With a median follow-up of 2.47 years, NOLUS-positive patients who achieved pCR had a 100% iDFS rate, mirroring the pCR versus residual disease patterns seen in triple-negative patients. NOLUS positivity was observed in 20.43% of patients aged 22-50, compared to 8.93% in those over 50, though this difference was not statistically significant.

Conclusion

NOLUS exhibits potential in predicting pCR in HR+/HER2- breast cancer, serving as a cost-effective substitute for genomic tests.

Axillary Management Following Neoadjuvant Chemotherapy in Clinically Node-Positive Breast Cancer

INTRODUCTION

Clinical trial data indicate that omitting axillary lymph node dissection (ALND) is feasible and may reduce morbidity for carefully selected patients with clinically node-positive breast cancer who achieve a pathological complete response (pCR) after neoadjuvant chemotherapy (NCT). However, there remains a need to understand how these findings translate to broader clinical practice and to identify which patients benefit most. This study utilizes a national dataset to assess outcomes in axillary management, aiming to inform best practice in axillary de-escalation.

METHODS

The National Cancer Data Base was used to identify women diagnosed with clinically node-positive invasive breast cancer between 2012 to 2020 who received NCT and subsequent ALND. Associations between clinicopathologic factors and axillary pCR were analyzed statistically.

RESULTS

Of the 59,791 patients included, 8,827 (14.76%) achieved nodal pCR. Patients with HR-negative and HER2-positive receptor status more frequently underwent ALND instead of sentinel lymph node biopsy. Conversely, patients over the age of 70, those with private or public insurance, and cases classified as ypT1 or ypT2 were less likely to undergo ALND.

CONCLUSION

A subset of patients with clinically node-positive breast cancer received ALND despite achieving axillary pCR following NCT. This highlights an opportunity to enhance precision in identifying candidates for axillary de-escalation, potentially reducing morbidity and tailoring treatment more closely to individual patient needs.

Conventional Tools for Predicting Satisfactory Response to Neoadjuvant Chemotherapy in HR+/HER2- Breast Cancer Patients

Aim

The aim of the study was to assess the role of Magee Equation 3 (MagEq3), IHC4 score, and HER2-low status in predicting "satisfactory response (SR)" to neoadjuvant chemotherapy (NAC) in HR+/HER2- breast cancer (BC) patients.

Methods

In a retrospective study, female patients of any age with T1-4, N0-2, M0 HR+/HER2- BC who received NAC and underwent adequate locoregional surgical treatment were included. Patients were grouped according to 2 outcomes: (a) overall response to NAC in breast and axilla by using residual cancer burden (RCB) criteria and (b) axillary downstaging after NAC by using N staging. 2 cohorts for overall response were overall SR (RCB 0-1) and no SR (RCB 2-3). On the other hand, for axillary downstaging, 2 cohorts constituted from axillary SR (ypN0 and ypN0i+) and no SR (ypNmic-N3). MagEq3 and IHC4 scores were calculated from their pathological tumor slides in each patient. HER2 status was categorized as either "no" or "low." In addition, patient age, family history, tumor histology, stage at admission, and Ki-67 status were compared between cohorts according to predefined outcomes.

Results

In a total of 230 BC patients, 228 patients were included to compare according to their RCB levels. The mean age of patients with overall SR was significantly lower than those without. Patients with high Ki-67 expression, high (>30) MagEq3 score, high ICH4 quartile, and HER2-low status had significantly more overall SR. On the other hand, only patients with high Ki-67 expression had significantly more axillary SR. MagEq3 score levels, ICH4 quartiles, and HER2 status were similar between patients with axillary SR and not.

Conclusion

MagEq3 and IHC4 tools seemed to be useful to predict those HR+/HER2- BC patients who are most likely to get benefit from NAC. But, only high Ki-67 expression level significantly predicted satisfactory axillary downstaging in HR+/HER2- BC patients.

Trends of axillary surgery in breast cancer patients with axillary lymph node metastasis: a comprehensive single-center retrospective study

Purpose

Based on the results of previous trials, de-escalation of axillary surgery after neoadjuvant chemotherapy (NAC) has increased in patients with axillary lymph node (ALN) metastasis at presentation. This study aimed to review the trends of axillary surgery by time period and molecular subtype in patients with ALN metastasis.

Methods

We analyzed the rates of sentinel lymph node biopsy (SLNB) and ALN dissection (ALND) based on time period and subtype. The time period was divided into 3 subperiods to determine the rate of axillary surgery type over time (period 1, from 2009 to 2012; period 2, from 2013 to 2016; and period 3, from 2017 to July 2019).

Results

From 2009 to July 2019, 2,525 breast cancer patients underwent surgery. Based on subtype, the ALND rate of hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) disease decreased by 13.0% from period 1 to period 3 (period 1, 99.4%; period 2, 97.5%; and period 3, 86.4%; P < 0.001). Conversely, the ALND rate in HR+/HER2+, HR-/HER2+, and triple-negative breast cancer (TNBC) significantly decreased by 43.7%, 48.8%, and 35.2% in period 1, period 2, and period 3, respectively (P < 0.001). In the patient group receiving NAC, HR+/HER2- had a significantly higher ALND rate (84.1%) than HR+/HER2+, HR-/HER2+, and TNBC (60.8%, 62.3%, and 70.7%, respectively; P < 0.001).

Conclusion

The SLNB rate in patients with ALN metastasis has increased over time. However, the ALND rate in HR+/HER2- was significantly higher than in other subtypes.

Evaluation of multigene assays as predictors for response to neoadjuvant chemotherapy in early-stage breast cancer patients

OncotypeDX and MammaPrint assays have not been validated to predict pathologic complete response (pCR) to neoadjuvant chemotherapy (NACT) in early-stage breast cancer patients. We analyzed the 2010-2019 National Cancer Database and found that high OncotypeDX recurrence scores or high MammaPrint scores were associated with greater odds of pCR. Our findings suggest that OncotypeDX and MammaPrint testing predict pCR after NACT and could facilitate clinical decision-making between clinicians and patients.

Predicting the Response of Neoadjuvant Chemotherapy in Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer With Axillary Lymph Node Metastasis by Multigene Assay

PURPOSE

The GenesWell™ breast cancer test (BCT) is a recently developed multigene assay that predicts the risk of distant recurrence in patients with hormone receptor-positive (HR+) and human epidermal growth factor-2 negative (HER2-) early breast cancer (BC). The ability of this assay to predict the response to neoadjuvant chemotherapy (NACT) has not been established to date.

METHODS

Biopsy specimens from HR+/HER2- BC patients with axillary lymph node (LN) metastasis who underwent NACT were analyzed using the BCT score. The modified BCT score was developed and patients classified into high-and low-response groups. A total of 88 patients were available for the BCT score among the 108 eligible patients. The median follow-up duration was 35.9 (7.8-128.5) months.

RESULTS

Among them, 61 (65.1%) had cN1 and 53 (60.2%) had cT1 or cT2 disease. The BCT score was low in 25 (28.4%) patients and high in 63 (71.6%). Among the 50 patients with pathologic complete response or partial response, 41 (82.0%) were in the high BCT score group and 9 (18.0%) were in the low BCT score group. Among the 38 patients with stable or progressive disease, 22 (57.9%) were in the high BCT score group and 16 (42.1%) were in the low BCT score group (p = 0.025). Ki-67 before NACT was a significant factor for predicting tumor response (p = 0.006; 3.81 [1.50-10.16]). The BCT score showed a significant response to NACT (p = 0.016; 4.18 [1.34-14.28]). Distant metastasis-free survival was significantly different between the high- and low-response groups (p = 0.004).

CONCLUSION

We demonstrated that the BCT score predicts NACT responsiveness in HR+/HER2- BC with LN metastasis and might help determine whether NACT should be performed. Further studies are required to validate these results.

Gene-expression signatures to inform neoadjuvant treatment decision in HR+/HER2- breast cancer: Available evidence and clinical implications

Over the last few years, the indication for chemotherapy use in HR+/HER2- early BC has been significantly modified by the introduction of gene-expression profiling. In the adjuvant setting, several gene-expression signatures have been validated to discriminate early stage HR+/HER2- BC with different prognosis and to identify patients for which adjuvant chemotherapy can be spared. Considering their ability to optimize the choice of adjuvant treatment and the increasing use of neoadjuvant approach in early BC, the potential use of gene-expression signatures to discriminate patients to be candidate to neoadjuvant chemotherapy or endocrine treatment appears particularly appealing. Indeed, the San Gallen Consensus Conference panel recently endorsed the use of genomic assays on core biopsies as a potential strategy for choosing the type of neoadjuvant treatment (chemotherapy or endocrine therapy) in selected patients. In this context, we here review evidence supporting the use of most common commercially available gene-expression signatures (Oncotype DX, MammaPrint, PAM50, EndoPredict and Breast Cancer Index) in patients receiving neoadjuvant therapy for HR+/HER2- BC. Data on the association of gene expression signatures and response to neoadjuvant chemotherapy or neoadjuvant endocrine therapy will be reviewed and the clinical implications of this data to guide the clinical decision-making process in early HR+/HER2- BC will be discussed.

Genetic and immunologic features of recurrent stage I lung adenocarcinoma

Although surgery for early-stage lung cancer offers the best chance of cure, recurrence still occurs between 30 and 50% of the time. Why patients frequently recur after complete resection of early-stage lung cancer remains unclear. Using a large cohort of stage I lung adenocarcinoma patients, distinct genetic, genomic, epigenetic, and immunologic profiles of recurrent tumors were analyzed using a novel recurrence classifier. To characterize the tumor immune microenvironment of recurrent stage I tumors, unique tumor-infiltrating immune population markers were identified using single cell RNA-seq on a separate cohort of patients undergoing stage I lung adenocarcinoma resection and applied to a large study cohort using digital cytometry. Recurrent stage I lung adenocarcinomas demonstrated higher mutation and lower methylation burden than non-recurrent tumors, as well as widespread activation of known cancer and cell cycle pathways. Simultaneously, recurrent tumors displayed downregulation of immune response pathways including antigen presentation and Th1/Th2 activation. Recurrent tumors were depleted in adaptive immune populations, and depletion of adaptive immune populations and low cytolytic activity were prognostic of stage I recurrence. Genomic instability and impaired adaptive immune responses are key features of stage I lung adenocarcinoma immunosurveillance escape and recurrence after surgery.

Relationship Between Breast and Axillary Pathologic Complete Response in Women Receiving Neoadjuvant Chemotherapy for Breast Cancer

OBJECTIVE

We aim to delineate the relationship between breast and axillary pathologic complete response (pCR) in patients receiving neoadjuvant chemotherapy for breast cancer.

METHODS

We performed a retrospective cohort study of patients with clinical T1-4N0-3M0 breast cancer receiving neoadjuvant chemotherapy followed by surgical therapy at Sunnybrook Health Sciences Centre in Toronto, Canada between 2014 and 2019. Clinicopathologic data were abstracted from the electronic medical record. Women were stratified into receptor subtypes as follows: hormone receptor positive (HR+)/human epidermal growth factor receptor 2 negative (HER2-), HR+/HER2+, HR-/HER2+ and HR-/HER2- (triple negative) and compared with Fisher's exact test. Our primary outcome was to assess the positive predictive value of breast pCR for determining axillary pCR, and vice versa.

RESULTS

There were 374 breast cancers, with 109 (29.1%) achieving breast pCR (ypT0/Tis). Amongst node-positive tumours achieving breast pCR, rates of associated axillary pCR (ypN0/0i+) were as follows: HR+/HER2- (2/6, 33.3%), HR+/HER2+ (12/13, 92.3%), HR-/HER2+ (15/17, 88.2%) and triple negative (15/17, 88.2%) (P = 0.02). Conversely, amongst node-positive tumours achieving axillary pCR, rates of associated breast pCR were: HR+/HER2- (2/10, 20.0%), HR+/HER2+ (12/23, 52.2%), HR-/HER2+ (15/24, 62.5%) and triple negative (15/26, 57.7%) (P = 0.1).

CONCLUSIONS

Breast pCR is a strong predictor of axillary pCR in women with HER2-positive and triple-negative breast cancers. Conversely, axillary pCR is a modest predictor of breast pCR for these subtypes. There is a poor relationship between breast and axillary pCR in women with hormone receptor-positive disease. These data may inform future de-escalation of surgery in women with HER2-positive and triple-negative disease.