Neo-adjuvant therapies for ER positive/HER2 negative breast cancers: from chemotherapy to hormonal therapy, CDK inhibitors, and beyond

INTRODUCTION

Chemotherapy has been traditionally used as neo-adjuvant therapy in breast cancer for down-staging of locally advanced disease in all sub-types. In the adjuvant setting, genomic assays have shown that a significant proportion of ER positive/HER2 negative patients do not derive benefit from the addition of chemotherapy to adjuvant endocrine therapy. An interest in hormonal treatments as neo-adjuvant therapies in ER positive/HER2 negative cancers has been borne by their documented success in the adjuvant setting. Moreover, cytotoxic chemotherapy is less effective in ER positive/HER2 negative disease compared with other breast cancer subtypes in obtaining pathologic complete responses.

AREAS COVERED

Neo-adjuvant therapies for ER positive/HER2 negative breast cancers and associated biomarkers are reviewed, using a Medline survey. A focus of discussion is the prediction of patients that are unlikely to derive extra benefit from chemotherapy and have the highest probabilities of benefiting from hormonal and other targeted therapies.

EXPERT OPINION

Predictive biomarkers of response to neo-adjuvant chemotherapy and hormonal therapies are instrumental for selecting ER positive/HER2 negative breast cancer patients for each treatment. Chemotherapy remains the standard of care for many of those patients requiring neo-adjuvant treatment, but other neo-adjuvant therapies are increasingly used.

Optimising of axillary therapy in breast cancer: lessons from the past to plan for a better future

In this narrative review, we aim to explore the ability of radiation therapy to eradicate breast cancer regional node metastasis. It is a journey through data of older trials without systemic therapy showing the magnitude of axillary therapy (surgery versus radiation) on cancer control. Considering that both systemic and loco-regional therapies were shown to reduce any recurrence with a complex interaction, our review includes surgical, radiation, and radiobiology consideration for breast cancer, and provide our view of future practise. The aim is to provide information optimise radiation therapy in the era of primary systemic therapy.

Correlation of an immune-related 8-gene panel with pathologic response to neoadjuvant chemotherapy in patients with primary breast cancers

Neoadjuvant chemotherapy (NACT)-induced pathologic complete response (pCR) is associated with a favorable prognosis for breast cancer. Prior research links tumor-infiltrating lymphocytes with breast cancer chemotherapy response, suggesting the tumor-immune microenvironment's role. The aim of this study was to evaluate the immune-related genes that exhibit associations with the response to NACT. In this study, we analyzed a total of 37 patients (aged 27-67) who received NACT as the first-line treatment for primary breast cancer, followed by surgery. This group consisted of nine patients (24.3 %) with estrogen receptor (ER)-positive/HER2-negative status, ten patients (27.0 %) with ER-positive/HER2-positive status, five patients (13.5 %) with ER-negative/HER2-positive status, and thirteen patients (35.1 %) with triple-negative breast cancer (TNBC). Among these patients, twelve (32.4 %) achieved a pCR, with eight (66.6 %) having HER2-positive tumors, and the remaining four having TNBC. To identify immune-related genes linked with pCR in subjects with breast cancer prior to NACT, we collected fresh tissues for next-generation sequencing. Patients with pCR had higher expressions of eight genes, KLRK1, IGJ, CD69, CD40LG, MS4A1, CD1C, KLRB1, and CA4, compared to non-pCR patients. The 8-gene signature was associated with good prognosis and linked to better relapse-free survival in patients receiving chemotherapy. The expression of these genes was involved in better drug response, displaying a positive correlation with the infiltration of immune cells. In conclusion, we have identified eight immune-related genes that are associated with a favorable prognosis and positive responses to drugs. This 8-gene signature could potentially provide prognostic insights for breast cancer patients undergoing NACT.

Integrated single-cell and bulk RNA sequencing analysis identifies a neoadjuvant chemotherapy-related gene signature for predicting survival and therapy in breast cancer

Neoadjuvant chemotherapy (NAC) is a well-established treatment modality for locally advanced breast cancer (BC). However, it can also result in severe toxicities while controlling tumors. Therefore, reliable predictive biomarkers are urgently needed to objectively and accurately predict NAC response. In this study, we integrated single-cell and bulk RNA-seq data to identify nine genes associated with the prognostic response to NAC: NDRG1, CXCL14, HOXB2, NAT1, EVL, FBP1, MAGED2, AR and CIRBP. Furthermore, we constructed a prognostic risk model specifically linked to NAC. The clinical independence and generalizability of this model were effectively demonstrated. Additionally, we explore the underlying cancer hallmarks and microenvironment features of this NAC response-related risk score, and further assess the potential impact of risk score on drug response. In summary, our study constructed and validated a nine-gene signature associated with NAC prognosis, which was accomplished through the integration of single-cell and bulk RNA data. The results of our study are of crucial significance in the prediction of the efficacy of NAC in BC, and may have implications for the clinical management of this disease.

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.

The Added Prognostic Value of Oncotype Recurrence Score to AJCC Prognostic Staging System in Stage III ER+/HER2- Breast Cancer

INTRODUCTION

Prognostic prediction based on prognostic stage (PS) with the Oncotype DX recurrence score (RS) has not been validated in stage III ER+/HER2- breast cancer. This study aimed to evaluate the added prognostic significance of RS incorporated with the PS system and to compare the prognostic prediction improvement with anatomic TNM stage (AS) using nomogram construction.

METHODS

The SEER database was indexed to identify ER+/HER2- invasive ductal or lobular breast cancer in AS IIIA-IIIC with RS results diagnosed from 2004 to 2013. Patients with RS < 18, 18-30 and > 30 were categorized into low-, intermediate- and high-risk RS groups. Comparisons of the distribution of clinical-pathologic characteristics among RS risk groups were performed using Pearson's chi-square test. Breast cancer-specific survival (BCSS) was estimated using the Kaplan-Meier method and compared across RS or PS by log-rank test. Cox regression was used to evaluate the factors independently related to BCSS. A nomogram comprised of PS and RS was constructed with discrimination, calibration and clinical benefit evaluated.

RESULTS

Altogether 629 patients who received RS were enrolled. There were 326 cases (51.8%) with low-risk RS, 237 (37.7%) with intermediate-risk RS and 66 (10.5%) with high-risk RS; 344 patients (54.7%) had PS IB, 84 (13.4%) had IIB, 150 (23.8%) had IIIA, 46 (7.3%) had IIIB, and only 5 had (0.8%) IIIC. Both PS and RS were independent prognostic factors for BCSS. There were significant or trends of differences in survival among RS within subtypes stratified by PS. There were significant differences in survival among PS only within intermediate-risk RS. A nomogram prediction 5-year BCSS was constructed with a c-index of 0.811. Lower histologic grade, positive PR and fewer positive lymph nodes were independently correlated with low-risk RS.

CONCLUSION

PS incorporated with RS had improved prognostic significance for stage III ER+/HER 2- breast cancer.

Prognostic and predictive biomarkers with therapeutic targets in breast cancer: A 2022 update on current developments, evidence, and recommendations

OBJECTIVE

To evaluate and validate the recent and emerging data for prognostic and predictive biomarkers with therapeutic targets in breast cancer.

DATA SOURCES

A literature search from January 2015 to March 2022 was performed using the key terms breast cancer, clinical practice guidelines, gene mutations, genomic assay, immune cancer therapy, predictive and/or prognostic biomarkers, and targeted therapies.

STUDY SELECTION AND DATA EXTRACTION

Relevant clinical trials, meta-analyses, seminal articles, and published evidence- and consensus-based clinical practice guidelines in the English language were identified, reviewed and evaluated.

DATA SYNTHESIS

Breast cancer is a biologically heterogeneous disease, leading to wide variability in treatment responses and survival outcomes. Biomarkers for breast cancer are evolving from traditional biomarkers in immunohistochemistry (IHC) such as estrogen receptor (ER), progesterone receptor (PR) and epidermal growth factor receptor type 2 (HER2) to genetic biomarkers with therapeutic implications (e.g. breast cancer susceptibility gene 1/2 [BRCA1/2], estrogen receptor α [ESR1] gene mutation, HER2 gene mutation, microsatellite instability [MSI], phosphatidylinositol 3-kinase catalytic subunit 3Cα [PIK3CA] gene mutation, neurotrophic tyrosine receptor kinase [NTRK] gene mutation). In addition, current data are most robust for biomarkers in immunotherapy (e.g. programmed cell death receptor ligand-1 [PD-L1], microsatellite instability-high [MSI-H] or deficient mismatch repair [dMMR]). Oncotype DX assay remains the best validated gene expression assay that is both predictive and prognostic whereas MammaPrint is prognostic for genomic risk.

CONCLUSIONS

Biomarker-driven therapies have the potential to confer greater therapeutic advantages than standard-of-care therapies. The purported survival benefits associated with biomarker-driven therapies should be weighed against their potential harms.

The Story of the Magee Equations: The Ultimate in Applied Immunohistochemistry

Magee equations (MEs) are a set of multivariable models that were developed to estimate the actual Onco type DX (ODX) recurrence score in invasive breast cancer. The equations were derived from standard histopathologic factors and semiquantitative immunohistochemical scores of routinely used biomarkers. The 3 equations use slightly different parameters but provide similar results. ME1 uses Nottingham score, tumor size, and semiquantitative results for estrogen receptor (ER), progesterone receptor, HER2, and Ki-67. ME2 is similar to ME1 but does not require Ki-67. ME3 includes only semiquantitative immunohistochemical expression levels for ER, progesterone receptor, HER2, and Ki-67. Several studies have validated the clinical usefulness of MEs in routine clinical practice. The new cut-off for ODX recurrence score, as reported in the Trial Assigning IndividuaLized Options for Treatment trial, necessitated the development of Magee Decision Algorithm (MDA). MEs, along with mitotic activity score can now be used algorithmically to safely forgo ODX testing. MDA can be used to triage cases for molecular testing and has the potential to save an estimated $300,000 per 100 clinical requests. Another potential use of MEs is in the neoadjuvant setting to appropriately select patients for chemotherapy. Both single and multi-institutional studies have shown that the rate of pathologic complete response (pCR) to neoadjuvant chemotherapy in ER+/HER2-negative patients can be predicted by ME3 scores. The estimated pCR rates are 0%, <5%, 14%, and 35 to 40% for ME3 score <18, 18 to 25, >25 to <31, and 31 or higher, respectively. This information is similar to or better than currently available molecular tests. MEs and MDA provide valuable information in a time-efficient manner and are available free of cost for anyone to use. The latter is certainly important for institutions in resource-poor settings but is also valuable for large institutions and integrated health systems.

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.

Predicting Chemotherapy Benefit across Different Races in Early-Stage Breast Cancer Patients Using the Oncotype DX Score

BACKGROUND

Oncotype DX assay, a multigene molecular test, has been widely used to stratify relapse risk and guide chemotherapy treatment in breast cancer. However, the optimal threshold of the Oncotype DX score in predicting chemotherapy benefit and its racial variation has not been investigated.

METHODS

In this study, we apply a random forest survival model to the SEER-Oncotype cohort data (Surveillance, Epidemiology, and End Results with Oncotype DX test information for breast cancer patients) and determine chemotherapy benefit thresholds in early-stage, estrogen-receptor-positive (ER+), and HER2-negative (HER2-) patients of different races.

RESULTS

Our results indicate that early-stage ER+, HER2-, and LN-/LN+ patients may benefit from receiving chemotherapy at a lower Oncotype DX score than current guidelines (Recurrence Score, RS > 25 or RS > 30) suggest. According to the estimated chemotherapy sensitivity thresholds from our models, 2.05-2.72-fold more lymph-node-negative (LN-) and 2.08-5.02-fold more lymph-node-positive (LN+) patients who may not currently be recommended for chemotherapy by their Oncotype DX test result may actually have the potential to benefit from chemotherapy. Furthermore, our models indicate a racial difference in chemotherapy benefit: white, black, and Asian women with early-stage ER+/LN- tumors benefit from chemotherapy when their Oncotype DX scores are greater than 19.9, 37.2, and 18.0, respectively.

CONCLUSIONS

Our study provides a method for calibrating multigene molecular tests to help guide treatment decisions in racially and ethnically diverse patients with cancer. Specifically, we identify key chemotherapy sensitivity thresholds for the Oncotype DX recurrence score test in breast cancer patients and provide evidence that certain patients may benefit from receiving chemotherapy at a lower threshold than the current clinical guidelines suggest.

Nab-paclitaxel weekly versus dose-dense solvent-based paclitaxel followed by dose-dense epirubicin plus cyclophosphamide in high-risk HR+/HER2- early breast cancer: results from the neoadjuvant part of the WSG-ADAPT-HR+/HER2- trial

BACKGROUND

In high-risk hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) early breast cancer (EBC), nanoparticle albumin-bound (nab)-paclitaxel showed promising efficacy versus solvent-based (sb)-paclitaxel in neoadjuvant trials; however, optimal patient and therapy selection remains a topic of ongoing research. Here, we investigate the potential of Oncotype DX® recurrence score (RS) and endocrine therapy (ET) response (low post-endocrine Ki67) for therapy selection.

PATIENTS AND METHODS

Within the WSG-ADAPT trial (NCT01779206), high-risk HR+/HER2- EBC patients were randomized to (neo)adjuvant 4× sb-paclitaxel 175 mg/m2 q2w or 8× nab-paclitaxel 125 mg/m2 q1w, followed by 4× epirubicin + cyclophosphamide (90 mg + 600 mg) q2w; inclusion criteria: (i) cN0-1, RS 12-25, and post-ET Ki67 >10%; (ii) cN0-1 with RS >25. Patients with cN2-3 or (G3, baseline Ki67 ≥40%, and tumor size >1 cm) were allowed to be included without RS and/or ET response testing. Associations of key factors with pathological complete response (pCR) (primary) and survival (secondary) endpoints were analyzed using statistical mediation and moderation models.

RESULTS

Eight hundred and sixty-four patients received neoadjuvant nab-paclitaxel (n= 437) or sb-paclitaxel (n = 427); nab-paclitaxel was superior for pCR (20.8% versus 12.9%, P = 0.002). pCR was higher for RS >25 versus RS ≤25 (16.0% versus 8.4%, P = 0.021) and for ET non-response versus ET response (15.1% versus 6.0%, P = 0.027); no factors were predictive for the relative efficacy of nab-paclitaxel versus sb-paclitaxel. Patients with pCR had longer distant disease-free survival [dDFS; hazard ratio 0.42, 95% confidence interval (CI) 0.20-0.91, P = 0.024]. Despite favorable prognostic association of RS >25 versus RS ≤25 with pCR (odds ratio 3.11, 95% CI 1.71-5.63, P ≤ 0.001), higher RS was unfavorably associated with dDFS (hazard ratio 1.03, 95% CI 1.01-1.05, P = 0.010).

CONCLUSIONS

In high-risk HR+/HER2- EBC, neoadjuvant nab-paclitaxel q1w appears superior to sb-paclitaxel q2w regarding pCR. Combining RS and ET response assessment appears to select patients with highest pCR rates. The disadvantage of higher RS for dDFS is reduced in patients with pCR. These are the first results from a large neoadjuvant randomized trial supporting the use of RS to help select patients for neoadjuvant chemotherapy in high-risk HR+/HER2- EBC.

Multigene profiles to guide the use of neoadjuvant chemotherapy for breast cancer: a Copenhagen Breast Cancer Genomics Study

Estrogen receptor (ER) and human epidermal growth factor 2 (HER2) expression guide the use of neoadjuvant chemotherapy (NACT) in patients with early breast cancer. We evaluate the independent predictive value of adding a multigene profile (CIT256 and PAM50) to immunohistochemical (IHC) profile regarding pathological complete response (pCR) and conversion of positive to negative axillary lymph node status. The cohort includes 458 patients who had genomic profiling performed as standard of care. Using logistic regression, higher pCR and node conversion rates among patients with Non-luminal subtypes are shown, and importantly the predictive value is independent of IHC profile. In patients with ER-positive and HER2-negative breast cancer an odds ratio of 9.78 (95% CI 2.60;36.8), P < 0.001 is found for pCR among CIT256 Non-luminal vs. Luminal subtypes. The results suggest a role for integrated use of up-front multigene subtyping for selection of a neoadjuvant approach in ER-positive HER2-negative breast cancer.

Optimal treatment strategy for hormone receptor-positive human epidermal growth factor receptor 2-negative breast cancer patients with 1-2 suspicious axillary lymph node metastases on breast magnetic resonance imaging: upfront surgery vs. neoadjuvant chemotherapy

Background

It is unclear whether upfront surgery or neoadjuvant chemotherapy is appropriate for first treatment in hormone receptor (HR)-positive human epidermal growth factor receptor 2 (HER2)-negative breast cancer patients with 1-2 suspicious axillary lymph node (ALN) metastases on preoperative breast magnetic resonance imaging (MRI).

Method

We identified 282 patients with HR+HER2- breast cancer and 1-2 suspicious ALN metastases on baseline breast MRI (147 received upfront surgery; 135 received neoadjuvant chemotherapy). We evaluated the predictive clinicopathological factors for pN2-3 in the adjuvant setting and axillary pathologic complete response (pCR) in the neoadjuvant setting.

Results

Lymphovascular invasion (LVI)-positive and clinical tumors >3 cm were significantly associated with pN2-3 in patients who received upfront surgery. The pN2-3 rate was 9.3% in patients with a clinical tumor ≤ 3 cm and LVI-negative versus 34.7% in the others (p < 0.001). The pN2-3 rate in patients with a clinical tumor ≤ 3 cm and LVI-negative and in the others were 9.3% versus 34.7% in all patients (p < 0.001), 10.7% versus 40.0% (p = 0.033) in patients aged < 50 years, and 8.5% versus 31.0% in patients aged ≥ 50 years (p < 0.001), respectively. In the neoadjuvant setting, patients with tumor-infiltrating lymphocytes (TILs) ≥ 20% had a higher axillary pCR than those with TILs < 20% (46.7% vs. 15.3%, p < 0.001). A similar significant finding was also observed in patients < 50 years.

Conclusions

Upfront surgery may be preferable for patients aged ≥ 50 years with a clinical tumor < 3 cm and LVI-negative, while neoadjuvant chemotherapy may be preferable for those aged < 50 years with TILs ≥ 20%.

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.

Contrast-enhanced mammography in the assessment of residual disease after neoadjuvant treatment

PURPOSE

To investigate the utility of contrast-enhanced mammography (CEM) as an alternative to breast MRI for the evaluation of residual disease after neoadjuvant treatment (NAT).

METHODS

This prospective study enrolled consecutive women undergoing NAT for breast cancer from July 2017-July 2019. Breast MRI and CEM exams performed after completion of NAT were read independently by two breast radiologists. Residual disease and lesion size on MRI and CEM recombined (RI) and low-energy images (LEI) were compared. Histopathology was considered the reference standard. Statistical analysis was performed using McNemar's and Leisenring's tests. Multiple comparison adjustment was made using Bonferroni procedure. Lesion sizes were correlated using Kendall's tau coefficient.

RESULTS

There were 110 participants with 115 breast cancers. Residual disease (invasive cancer or ductal carcinoma in situ) was detected in 83/115 (72%) lesions on pathology, 71/115 (62%) on MRI, 55/115 (48%) on CEM RI, and 75/115 (65%) on CEM LEI. When using multiple comparison adjustment, no significant differences were detected between MRI combined with CEM LEI and CEM RI combined with CEM LEI, in terms of accuracy (MRI: 77%, CEM: 72%; p ≥ 0.99), sensitivity (MRI: 88%, CEM: 81%; p ≥ 0.99), specificity (MRI: 47%, CEM: 50%; p ≥ 0.99), PPV (MRI: 81%, CEM: 81%; p ≥ 0.99), or NPV (MRI: 60%, CEM: 50%; p ≥ 0.99). Size correlation between pathology and both MRI combined with CEM LEI and CEM RI combined with CEM LEI was moderate: τ = 0. 36 vs 0.33 (p ≥ 0.99).

CONCLUSION

Contrast-enhanced mammography is an acceptable alternative to breast MRI for the detection of residual disease after neoadjuvant treatment.

Tumor immune microenvironment components and the other markers can predict the efficacy of neoadjuvant chemotherapy for breast cancer

Breast cancer is an epithelial malignant tumor that occurs in the terminal ducts of the breast. Neoadjuvant chemotherapy (NACT) is an important part of breast cancer treatment. Its purpose is to use systemic treatment for some locally advanced breast cancer patients, to decrease the tumor size and clinical stage so that non-operable breast cancer patients can have a chance to access surgical treatment, or patients who are not suitable for breast-conserving surgery can get the opportunity of breast-conserving. However, some patients who do not respond to NACT will lead deterioration in their condition. Therefore, prediction of NACT efficacy in breast cancer is vital for precision therapy. The tumor microenvironment (TME) has a crucial role in the carcinogenesis and therapeutic response of breast cancer. In this review, we summarized the immune cells, immune checkpoints, and other biomarkers in the TME that can evaluate the efficacy of NACT in treating breast cancer. We believe that the detection and evaluation of the TME components in breast cancer are helpful to predict the efficacy of NACT, and the prediction methods are in the prospect. In addition, we also summarized other predictive factors of NACT, such as imaging examination, biochemical markers, and multigene/multiprotein profiling.

A radiomic model to classify response to neoadjuvant chemotherapy in breast cancer

BACKGROUND

Medical image analysis has evolved to facilitate the development of methods for high-throughput extraction of quantitative features that can potentially contribute to the diagnostic and treatment paradigm of cancer. There is a need for further improvement in the accuracy of predictive markers of response to neo-adjuvant chemotherapy (NAC). The aim of this study was to develop a radiomic classifier to enhance current approaches to predicting the response to NAC breast cancer.

METHODS

Data on patients treated for breast cancer with NAC prior to surgery who had a pre-NAC dynamic contrast enhanced breast MRI were included. Response to NAC was assessed using the Miller-Payne system on the excised tumor. Tumor segmentation was carried out manually under the supervision of a consultant breast radiologist. Features were selected using least absolute shrinkage selection operator regression. A support vector machine learning model was used to classify response to NAC.

RESULTS

74 patients were included. Patients were classified as having a poor response to NAC (reduction in cellularity < 90%, n = 44) and an excellent response (> 90% reduction in cellularity, n = 30). 4 radiomics features (discretized kurtosis, NGDLM contrast, GLZLM_SZE and GLZLM_ZP) were identified as pertinent predictors of response to NAC. A SVM model using these features stratified patients into poor and excellent response groups producing an AUC of 0.75. Addition of estrogen receptor status improved the accuracy of the model with an AUC of 0.811.

CONCLUSION

This study identified a radiomic classifier incorporating 4 radiomics features to augment subtype based classification of response to NAC in breast cancer.

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.

Tailoring neoadjuvant treatment of HR-positive/HER2-negative breast cancers: Which role for gene expression assays?

Neoadjuvant chemotherapy (NACT) for breast cancer (BC) increases surgical and conservative surgery chances. However, a significant proportion of patients will not be eligible for conservative surgery following NACT because of large tumor size and/or low chemosensitivity, especially for hormone receptor (HR)-positive/ human epidermal growth factor receptor 2 (HER2)-negative tumors, for which pathological complete response rates are lower than for other BC subtypes. On the other hand, for luminal BC neoadjuvant endocrine therapy could represent a valid alternative. Several gene expression assays have been introduced into clinical practice in last decades, in order to define prognosis more accurately than clinico-pathological features alone and to predict the benefit of adjuvant treatments. A series of studies have demonstrated the feasibility of using core needle biopsy for gene expression risk testing, finding a high concordance rate in the risk result between biopsy sample and surgical samples. Based on these premises, recent efforts have focused on the utility of gene expression signatures to guide therapeutic decisions even in the neoadjuvant setting. Several prospective and retrospective studies have investigated the correlation between gene expression risk score from core needle biopsy before neoadjuvant therapy and the likelihood of 1) clinical and pathological response to neoadjuvant chemotherapy and endocrine therapy, 2) conservative surgery after neoadjuvant chemotherapy and endocrine therapy, and 3) survival following neoadjuvant chemotherapy and endocrine therapy. The purpose of this review is to provide an overview of the potential clinical utility of the main commercially available gene expression panels (Oncotype DX, MammaPrint, EndoPredict, Prosigna/PAM50 and Breast Cancer Index) in the neoadjuvant setting, in order to better inform decision making for luminal BC beyond the exclusive contribution of clinico-pathological features.

Predictive Biomarkers of Response to Neoadjuvant Chemotherapy in Breast Cancer: Current and Future Perspectives for Precision Medicine

Pathological complete response (pCR) after neoadjuvant chemotherapy in patients with early breast cancer is correlated with better survival. Meanwhile, an expanding arsenal of post-neoadjuvant treatment strategies have proven beneficial in the absence of pCR, leading to an increased use of neoadjuvant systemic therapy in patients with early breast cancer and the search for predictive biomarkers of response. The better prediction of response to neoadjuvant chemotherapy could enable the escalation or de-escalation of neoadjuvant treatment strategies, with the ultimate goal of improving the clinical management of early breast cancer. Clinico-pathological prognostic factors are currently used to estimate the potential benefit of neoadjuvant systemic treatment but are not accurate enough to allow for personalized response prediction. Other factors have recently been proposed but are not yet implementable in daily clinical practice or remain of limited utility due to the intertumoral heterogeneity of breast cancer. In this review, we describe the current knowledge about predictive factors for response to neoadjuvant chemotherapy in breast cancer patients and highlight the future perspectives that could lead to the better prediction of response, focusing on the current biomarkers used for clinical decision making and the different gene signatures that have recently been proposed for patient stratification and the prediction of response to therapies. We also discuss the intratumoral phenotypic heterogeneity in breast cancers as well as the emerging techniques and relevant pre-clinical models that could integrate this biological factor currently limiting the reliable prediction of response to neoadjuvant systemic therapy.

Breast Cancer Patients: Who Would Benefit from Neoadjuvant Chemotherapies?

Neoadjuvant chemotherapy (NACT) was developed with the aims of shrinking tumors or stopping cancer cells from spreading before surgery. Unfortunately, not all breast cancer patients will benefit from NACT, and thus, patients must weigh the risks and benefits of treatment prior to the initiation of therapy. Currently, the data for predicting the efficacy of NACT is limited. Molecular testing, such as Oncotype DX, MammaPrint, and Curebest 95GC, have been developed to assist which breast cancer patients will benefit from the treatment. Patients with an increased level of Human Leukocyte Antigen-DR isotype, tumor-infiltrating lymphocytes, Fizzy-related protein homolog, and a decreased level of tumor-associated macrophages appear to benefit most from NACT.

A 10-miRNA risk score-based prediction model for pathological complete response to neoadjuvant chemotherapy in hormone receptor-positive breast cancer

Patients with hormone receptor (HR)-positive tumors breast cancer usually experience a relatively low pathological complete response (pCR) to neoadjuvant chemotherapy (NAC). Here, we derived a 10-microRNA risk score (10-miRNA RS)-based model with better performance in the prediction of pCR and validated its relation with the disease-free survival (DFS) in 755 HR-positive breast cancer patients (273, 265, and 217 in the training, internal, and external validation sets, respectively). This model, presented as a nomogram, included four parameters: the 10-miRNA RS found in our previous study, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) status, and volume transfer constant (K^trans). Favorable calibration and discrimination of 10-miRNA RS-based model with areas under the curve (AUC) of 0.865, 0.811, and 0.804 were shown in the training, internal, and external validation sets, respectively. Patients who have higher nomogram score (>92.2) with NAC treatment would have longer DFS (hazard ratio=0.57; 95%CI: 0.39-0.83; P=0.004). In summary, our data showed the 10-miRNA RS-based model could precisely identify more patients who can attain pCR to NAC, which may help clinicians formulate the personalized initial treatment strategy and consequently achieves better clinical prognosis for patients with HR-positive breast cancer.

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.

Biomarker discovery studies for patient stratification using machine learning analysis of omics data: a scoping review

OBJECTIVE

To review biomarker discovery studies using omics data for patient stratification which led to clinically validated FDA-cleared tests or laboratory developed tests, in order to identify common characteristics and derive recommendations for future biomarker projects.

DESIGN

Scoping review.

METHODS

We searched PubMed, EMBASE and Web of Science to obtain a comprehensive list of articles from the biomedical literature published between January 2000 and July 2021, describing clinically validated biomarker signatures for patient stratification, derived using statistical learning approaches. All documents were screened to retain only peer-reviewed research articles, review articles or opinion articles, covering supervised and unsupervised machine learning applications for omics-based patient stratification. Two reviewers independently confirmed the eligibility. Disagreements were solved by consensus. We focused the final analysis on omics-based biomarkers which achieved the highest level of validation, that is, clinical approval of the developed molecular signature as a laboratory developed test or FDA approved tests.

RESULTS

Overall, 352 articles fulfilled the eligibility criteria. The analysis of validated biomarker signatures identified multiple common methodological and practical features that may explain the successful test development and guide future biomarker projects. These include study design choices to ensure sufficient statistical power for model building and external testing, suitable combinations of non-targeted and targeted measurement technologies, the integration of prior biological knowledge, strict filtering and inclusion/exclusion criteria, and the adequacy of statistical and machine learning methods for discovery and validation.

CONCLUSIONS

While most clinically validated biomarker models derived from omics data have been developed for personalised oncology, first applications for non-cancer diseases show the potential of multivariate omics biomarker design for other complex disorders. Distinctive characteristics of prior success stories, such as early filtering and robust discovery approaches, continuous improvements in assay design and experimental measurement technology, and rigorous multicohort validation approaches, enable the derivation of specific recommendations for future studies.

Radiogenomic Signatures of Oncotype DX Recurrence Score Enable Prediction of Survival in Estrogen Receptor-Positive Breast Cancer: A Multicohort Study

Background Radiogenomics explores the association between imaging features and genomic assays to uncover relevant prognostic features; however, the prognostic implications of the derived signatures remain unclear. Purpose To identify preoperative radiogenomic signatures of estrogen receptor-positive breast cancer associated with the Oncotype DX recurrence score (RS) and to evaluate whether they are biomarkers for survival and responses to neoadjuvant chemotherapy (NACT). Materials and Methods In this retrospective multicohort study, three data sets were analyzed. The radiogenomic development data set, with preoperative dynamic contrast-enhanced MRI and RS data obtained between January 2016 and October 2019 was used to identify radiogenomic signatures. Prognostic implications of the imaging signatures were assessed by measuring overall survival and recurrence-free survival in the prognostic assessment data set using a multivariable Cox proportional hazards model. The therapeutic implication of the radiogenomic signatures was evaluated by determining their ability to predict the response to NACT using the treatment assessment data set obtained between August 2015 and March 2019. Prediction performance was estimated by using the area under the receiver operating characteristic curve (AUC). Results The final cohorts included a radiogenomic development data set with 130 women (mean age, 52 years ± 10 [standard deviation]), a prognostic assessment data set with 116 women (mean age, 48 years ± 9), and a treatment assessment data set with 135 women (mean age, 50 years ± 11). Radiogenomic signatures (n = 11) of texture and morphologic and statistical features were identified to generate the predicted RS (R² = 0.33, P < .001). A predicted RS greater than 29.9 was associated with poor overall and recurrence-free survival (P = .001 and P = .007, respectively); predicted RS was greater in women with a good NACT response (30.51 ± 6.92 vs 27.35 ± 4.04 [responders vs nonresponders], P = .001). By combining the predicted RS and complementary features, the model achieved improved performance in prediction of the NACT response (AUC, 0.85; P < .001). Conclusion Radiogenomic signatures associated with genomic assays provide markers of prognosis and treatment in estrogen receptor-positive breast cancer. © RSNA, 2021 Online supplemental material is available for this article.

Advancement of prognostic models in breast cancer: a narrative review

Objective

To provide a reference for clinical work and guide the decision-making of healthcare providers and end-users, we systematically reviewed the development, validation and classification of classical prognostic models for breast cancer.

Background

Patients suffering from breast cancer have different prognosis for its high heterogeneity. Accurate prognosis prediction and risk stratification for breast cancer are crucial for individualized treatment. There is a lack of systematic summary of breast cancer prognostic models.

Methods

We conducted a PubMed search with keywords "breast neoplasm", "prognostic model", "recurrence" and "metastasis", and screened the retrieved publications at three levels: title, abstract and full text. We identified the articles presented the development and/or validation of models based on clinicopathological factors, genomics, and machine learning (ML) methods to predict survival and/or benefits of adjuvant therapy in female breast cancer patients.

Conclusions

Combining prognostic-related variables with long-term clinical outcomes, researchers have developed a series of prognostic models based on clinicopathological parameters, genomic assays, and medical figures. The discrimination, calibration, overall performance, and clinical usefulness were validated by internal and/or external verifications. Clinicopathological models integrated the clinical parameters, including tumor size, histological grade, lymph node status, hormone receptor status to provide prognostic information for patients and doctors. Gene-expression assays deeply revealed the molecular heterogeneity of breast cancer, some of which have been cited by AJCC and National Comprehensive Cancer Network (NCCN) guidelines. In addition, the models based on the ML methods provided more detailed information for prognosis prediction by increasing the data dimension. Combined models incorporating clinical variables and genomics information are still required to be developed as the focus of further researches.

Molecular Biomarkers Predict Pathological Complete Response of Neoadjuvant Chemotherapy in Breast Cancer Patients: Review

Simple Summary

Breast cancer is the most common cancer in women worldwide. Although many studies have aimed to understand the genetic basis of breast cancer, leading to increasingly accurate diagnoses, only a few molecular biomarkers are used in clinical practice to predict response to therapy. Current studies aim to develop more personalized therapies to decrease the adverse effects of chemotherapy. Personalized medicine not only requires clinical, but also molecular characterization of tumors, which allows the use of more effective drugs for each patient. The aim of this study was to identify potential molecular biomarkers that can predict the response to therapy after neoadjuvant chemotherapy in patients with breast cancer. In this review, we summarize genomic, transcriptomic, and proteomic biomarkers that can help predict the response to therapy.

Abstract

Neoadjuvant chemotherapy (NAC) is often used to treat locally advanced disease for tumor downstaging, thus improving the chances of breast-conserving surgery. From the NAC response, it is possible to obtain prognostic information as patients may reach a pathological complete response (pCR). Those who do might have significant advantages in terms of survival rates. Breast cancer (BC) is a heterogeneous disease that requires personalized treatment strategies. The development of targeted therapies depends on identifying biomarkers that can be used to assess treatment efficacy as well as the discovery of new and more accurate therapeutic agents. With the development of new “OMICS” technologies, i.e., genomics, transcriptomics, and proteomics, among others, the discovery of new biomarkers is increasingly being used in the context of clinical practice, bringing us closer to personalized management of BC treatment. The aim of this review is to compile the main biomarkers that predict pCR in BC after NAC.

How Does Invasive Breast Cancer Oncotype Dx Recurrence Score on Core Needle Biopsies Influence Neoadjuvant Treatment Decision? A Descriptive Study

Background:

Oncotype Dx (ODx) is a genomic assay which estimates the risk of distant recurrence and predicts adjuvant chemotherapy benefit in early stage breast cancer patients. Most ODx data is derived from excisional specimens.

Aim:

We assess the utility of ODx on core needle biopsies (CNB) and measure its impact on neoadjuvant treatment decisions, particularly in patients with clinically complicated situations.

Methods:

Consecutive ODx results on breast CNBs with invasive carcinoma from 2012-2020 at 3 tertiary care hospitals with dedicated Breast Health Centers were reviewed. Clinical indications to perform ODx on CNB were recorded through a review of patients’ electronic medical records. Clinicopathologic features, surgical or oncologic modalities and follow-up data were recorded.

Results:

Three distinct clinical indications for performing ODx on CNB in 85 ER+ invasive breast carcinomas were identified: 1) Excisions with insufficient tissue to perform ODx, 2) adjudicate neoadjuvant therapy versus primary surgical resection, and 3) select neoadjuvant chemotherapy (NAC) versus neoadjuvant endocrine therapy (NET). Primary surgery was selected in patients with low score RS (<18), and NET was preferred in patients with intermediate or high RS (>18). NET was preferred over NAC in patients with low RS (<18).

Conclusion:

This study shows that CNB ODx RS helps guide treatment decisions in a neoadjuvant setting along with other contributing factors such as the presence of pathogenic mutations, node positivity, patient age, and comorbidities. The use of ODx on CNB is furthermore valuable in the midst of the COVID-19 pandemic for early breast cancer patients to administer effective therapy in a timely manner.

Palpable Adenopathy Does Not Indicate High-Volume Axillary Nodal Disease in Hormone Receptor-Positive Breast Cancer

BACKGROUND

Axillary metastases in the form of palpable adenopathy indicate the need for neoadjuvant chemotherapy or axillary lymph node dissection (ALND). Patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) disease infrequently have nodal pathologic complete response to neoadjuvant chemotherapy and often require ALND. Sentinel lymph node biopsy is an accepted treatment for patients with two or fewer non-palpable nodal metastases who are undergoing breast conservation. The proportion of patients with HR+/HER2- disease with palpable adenopathy and two or fewer nodal metastases is unknown.

METHODS

Patients with cT1-T3N1 HR+/HER2- disease with palpable adenopathy were identified from a prospective database. Patients who underwent mastectomy or breast-conserving therapy with ALND were included in this study, whereas patients who received neoadjuvant chemotherapy were excluded. Clinicopathologic characteristics were compared between patients with two or fewer or more than two positive nodes on ALND.

RESULTS

Of 180 patients included, 78 (43%) had two or fewer positive nodes on ALND, including 40/72 patients (56%) who underwent lumpectomy. On univariate analysis, cT1 tumor, unifocal tumor, only one palpable node, and two or fewer suspicious nodes on ultrasound were associated with two or fewer positive nodes on ALND. On multivariable analysis, number of suspicious nodes on ultrasound and cT stage were independently associated with two or fewer positive nodes on ALND.

CONCLUSIONS

A substantial minority of patients with cT1-3N1 HR+/HER2- disease with palpable adenopathy had two or fewer positive nodes on ALND. Standard clinicopathologic features and ultrasound findings can help identify candidates for upfront sentinel lymph node biopsy as a strategy to avoid ALND. Prospective studies evaluating this approach are warranted.

Using Breast Cancer Gene Expression Signatures in Clinical Practice: Unsolved Issues, Ongoing Trials and Future Perspectives

The development of gene expression signatures since the early 2000's has offered standardized assays to evaluate the prognosis of early breast cancer. Five signatures are currently commercially available and recommended by several international guidelines to individualize adjuvant chemotherapy decisions in hormone receptors-positive/HER2-negative early breast cancer. However, many questions remain unanswered about their predictive ability, reproducibility and external validity in specific populations. They also represent a new hope to tailor (neo)adjuvant systemic treatment, adjuvant radiation therapy, hormone therapy duration and to identify a subset of patients who might benefit from CDK4/6 inhibitor adjuvant treatment. This review will highlight these particular issues, address the remaining questions and discuss the ongoing and future trials.

Evaluation of risk stratification using gene expression assays in patients with breast cancer receiving neoadjuvant chemotherapy

PURPOSE

To evaluate the association of various gene expression assays with pathologic complete response (pCR) in the setting of neoadjuvant chemotherapy among patients with breast cancer METHODS: The National Cancer Database (NCDB) was queried for women diagnosed between 2010 and 2017 with stage I-III breast cancer who underwent neoadjuvant chemotherapy and either 21-gene recurrence score (RS) or 70-gene signature (GS). Logistic multivariable analysis (MVA) was performed to identify variables associated with pCR.

RESULTS

A total of 3009 patients met our inclusion criteria. The median follow up was 48.0 months (interquartile range 32.2-66.7 months). On logistic MVA for all patients, those with a high risk from GS (adjusted odds ratio [aOR] 3.23, 95% confidence interval [CI] 1.49-8.13, p = 0.006) or with RS ≥ 31 (aOR 1.99, 95% CI 1.41-2.82, p < 0.001) were more likely to have pCR. When compared to RS ≥ 31, a high risk from GS was not associated with pCR (aOR 1.01, 95% CI 0.75-1.37, p = 0.94). However, among those with favorable hormone receptor status, similar findings were noted, except that those with a high risk group from GS were less likely to have pCR compared to those with RS ≥ 31 (aOR 0.65, 95% CI 0.43-0.96, p = 0.03). When analyses were repeated using a high risk group from RS defined as RS ≥ 26 among those with favorable hormone receptor status, RS ≥ 26 was not associated with pCR when compared to the high risk from GS (aOR 0.74, 0.50-1.07, p = 0.12).

CONCLUSIONS

To our knowledge, this is the largest study using a nationwide oncology database suggesting that high recurrence risk groups in both assays were associated with pCR. Among those with favorable hormone receptor status, RS ≥ 31 may be a more selective prognostic marker for pCR.

Comparison of multiple oncotype DX® from the same patient

For women with breast cancer in whom multiple Oncotype DX^® Recurrence Scores (RS) are obtained, RS concordance utilizing current NCCN recommendations has not been evaluated. Patients with two or more RS were identified. RS were stratified by NCCN guidelines and compared for concordance. Twenty-four patients were evaluated. RS concordance varied by tumor type: 100% in the same tumor, 91.7% in multiple ipsilateral tumors, 71.4% in contralateral tumors, and 66.7% in in-breast recurrent tumors. RS concordance for multiple assays in the same patient is not high enough to omit Oncotype DX^® testing for each tumor.

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.

Is the 21-Gene Recurrence Score on Core Needle Biopsy Equivalent to Surgical Specimen in Early-Stage Breast Cancer? A Comparison of Gene Expression Between Paired Core Needle Biopsy and Surgical Specimens

BACKGROUND

Molecular testing on surgical specimens predicts disease recurrence and benefit of adjuvant chemotherapy in hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) early-stage breast cancer (EBC). Testing on core biopsies has become common practice despite limited evidence of concordance between core/surgical samples. In this study, we compared the gene expression of the 21 genes and the recurrence score (RS) between paired core/surgical specimens.

METHODS

Eighty patients with HR+/HER2- EBC were evaluated from two publicly available gene expression datasets (GSE73235, GSE76728) with paired core/surgical specimens without neoadjuvant systemic therapy. The expression of the 21 genes was compared in paired samples. A microarray-based RS was calculated and a value ≥ 26 was defined as high-RS. The concordance rate and kappa statistic were used to evaluate the agreement between the RS of paired samples.

RESULTS

Overall, there was no significant difference and a high correlation in the gene expression levels of the 21 genes between paired samples. However, CD68 and RPLP0 in GSE73235, AURKA, BAG1, and TFRC in GSE76728, and MYLBL2 and ACTB in both datasets exhibited weak to moderate correlation (r < 0.5). There was a high correlation of the microarray-based RS between paired samples in GSE76728 (r = 0.91, 95% confidence interval [CI] 0.81-0.96) and GSE73235 (r = 0.82, 95% CI 0.71-0.89). There were no changes in RS category in GSE76728, whereas 82% of patients remained in the same RS category in GSE73235 (κ = 0.64).

CONCLUSIONS

Gene expression levels of the 21-gene RS showed a high correlation between paired specimens. Potential sampling and biological variability on a set of genes need to be considered to better estimate the RS from core needle biopsy.

The impact of progesterone receptor negativity on oncological outcomes in oestrogen-receptor-positive breast cancer

Background

Oestrogen receptor (ER) status provides invaluable prognostic and therapeutic information in breast cancer (BC). When clinical decision making is driven by ER status, the value of progesterone receptor (PgR) status is less certain. The aim of this study was to describe clinicopathological features of ER-positive (ER+)/PgR-negative (PgR-) BC and to determine the effect of PgR negativity in ER+ disease.

Methods

Consecutive female patients with ER+ BC from a single institution were included. Factors associated with PgR- disease were assessed using binary logistic regression. Oncological outcome was assessed using Kaplan–Meier and Cox regression analysis.

Results

In total, 2660 patients were included with a mean(s.d.) age of 59.6(13.3) years (range 21–99 years). Median follow-up was 97.2 months (range 3.0–181.2). Some 2208 cases were PgR+ (83.0 per cent) and 452 were PgR- (17.0 per cent). Being postmenopausal (odds ratio (OR) 1.66, 95 per cent c.i. 1.25 to 2.20, P < 0.001), presenting with symptoms (OR 1.71, 95 per cent c.i. 1.30 to 2.25, P < 0.001), ductal subtype (OR 1.51, 95 per cent c.i. 1.17 to 1.97, P = 0.002) and grade 3 tumours (OR 2.20, 95 per cent c.i. 1.68 to 2.87, P < 0.001) were all associated with PgR negativity. In those receiving neoadjuvant chemotherapy (308 patients), pathological complete response rates were 10.1 per cent (25 of 247 patients) in patients with PgR+ disease versus 18.0 per cent in PgR- disease (11 of 61) (P = 0.050). PgR negativity independently predicted worse disease-free (hazard ratio (HR) 1.632, 95 per cent c.i. 1.209 to 2.204, P = 0.001) and overall survival (HR 1.774, 95 per cent c.i. 1.324 to 2.375, P < 0.001), as well as worse overall survival in ER+/HER2- disease (P = 0.004).

Conclusions

In ER+ disease, PgR- tumours have more aggressive clinicopathological features and worse oncological outcomes. Neoadjuvant and adjuvant therapeutic strategies should be tailored according to PgR status.

Can We Reliably Identify the Pathological Outcomes of Neoadjuvant Chemotherapy in Patients with Breast Cancer? Development and Validation of a Logistic Regression Nomogram Based on Preoperative Factors

BACKGROUND

Pathological responses of neoadjuvant chemotherapy (NCT) are associated with survival outcomes in patients with breast cancer. Previous studies constructed models using out-of-date variables to predict pathological outcomes, and lacked external validation, making them unsuitable to guide current clinical practice.

OBJECTIVE

The aim of this study was to develop and validate a nomogram to predict the objective remission rate (ORR) of NCT based on pretreatment clinicopathological variables.

METHODS

Data from 110 patients with breast cancer who received NCT were used to establish and calibrate a nomogram for pathological outcomes based on multivariate logistic regression. The predictive performance of this model was further validated using a second cohort of 55 patients with breast cancer. Discrimination of the prediction model was assessed using an area under the receiver operating characteristic curve (AUC), and calibration was assessed using calibration plots. The diagnostic odds ratio (DOR) was calculated to further evaluate the performance of the nomogram and determine the optimal cut-off value.

RESULTS

The final multivariate regression model included age, NCT cycles, estrogen receptor, human epidermal growth factor receptor 2 (HER2), and lymphovascular invasion. A nomogram was developed as a graphical representation of the model and showed good calibration and discrimination in both sets (an AUC of 0.864 and 0.750 for the training and validation cohorts, respectively). Finally, according to the Youden index and DORs, we assigned an optimal ORR cut-off value of 0.646.

CONCLUSION

We developed a nomogram to predict the ORR of NCT in patients with breast cancer. Using the nomogram, for patients who are operable and whose ORR is < 0.646, we believe that the benefits of NCT are limited and these patients can be treated directly using surgery.

Value of a 21-gene expression assay on core biopsy to predict neoadjuvant chemotherapy response in breast cancer: systematic review and meta-analysis

BACKGROUND

A recurrence score based on a 21-gene expression assay predicts the benefit of adjuvant chemotherapy in oestrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. This systematic review aimed to determine whether the 21-gene expression assay performed on core biopsy at diagnosis predicted pathological complete response (pCR) to neoadjuvant chemotherapy.

METHODS

The study was performed according to PRISMA guidelines. Relevant databases were searched to identify studies assessing the value of the 21-gene expression assay recurrence score in predicting response to neoadjuvant chemotherapy in patients with breast cancer. The Newcastle-Ottawa Scale was used to assess the quality of the studies. Results are reported as risk ratio (RR) with 95 per cent confidence interval using the Cochrane-Mantel-Haenszel method for meta-analysis. Sensitivity analyses were carried out where appropriate.

RESULTS

Seven studies involving 1744 patients reported the correlation between pretreatment recurrence score and pCR. Of these, 777 patients (44.6 per cent) had a high recurrence score and 967 (55.4 per cent) a low-intermediate score. A pCR was achieved in 94 patients (5.4 per cent). The pCR rate was significantly higher in the group with a high recurrence score than in the group with a low-intermediate score (10.9 versus 1.1 per cent; RR 4.47, 95 per cent c.i. 2.76 to 7.21; P < 0.001). A significant risk difference was observed between the two groups (risk difference 0.10, 0.04 to 0.15; P = 0.001).

CONCLUSION

A high recurrence score is associated with higher pCR rates and a low-intermediate recurrence score may indicate chemoresistance. Routine assessment of recurrence score by the 21-gene expression assay on core biopsy might be of value when considering neoadjuvant chemotherapy in patients with ER-positive, HER2-negative breast cancer.

Locoregional therapy in breast cancer patients treated with neoadjuvant chemotherapy

Introduction: Neoadjuvant chemotherapy (NAC) is increasingly used preoperatively in breast cancer patients to achieve disease downstaging, reduce distant dissemination, and assess chemosensitivity. While NAC indications are expanding, knowledge of its impact on subsequent locoregional treatment with surgery and radiation therapy (RT) decisions is evolving. Radiation oncologists are often called upon to estimate locoregional recurrence (LRR) risks and provide recommendations for adjuvant RT to the breast/chest wall and regional lymph nodes postoperatively. In the non-NAC setting, adjuvant RT decisions are guided by the pathology findings after definitive surgery. In the NAC setting, decisions for or against adjuvant RT are complex, particularly in patients who achieve complete pathologic response (pCR).Areas covered: This review will examine contemporary data on NAC in patients with breast cancer and discuss its impact on surgical and RT decisions. We will also evaluate controversies in the role of LRRT for these patients, focussing on prognostic factors that include biological subtypes and pCR after NAC.Expert opinion: Advances in personalized medicine and diagnostic techniques have shifted paradigms and increased complexities in locoregional treatment decisions, particularly in the setting of NAC. Despite the challenges, our goals while we await prospective data remain focused on improving survival, minimizing toxicity, and optimizing function and cosmesis.

Neoadjuvant Chemotherapy in Breast Cancer: Review of the Evidence and Conditions That Facilitated Its Use during the Global Pandemic

Practice and behaviour change in healthcare is complex, and requires a set of critical steps that would be needed to implement and sustain the change. Neoadjuvant chemotherapy for breast cancer is traditionally used for locally advanced disease and is primarily advantageous for surgical downstaging purposes. However, it does also offer patients with certain biologic subtypes such as the triple negative or Her2 positive breast cancers the opportunity to improve survival, even in early stage disease. During the height of the pandemic, an opportunity and motivation for the increased use of neoadjuvant therapy in breast cancer was identified. This paper describes the conditions that have supported this practice change at the provider and institutional levels. We also include our own institutional algorithm based on tumor biology and extent of disease that have guided our decisions on breast cancer management during the pandemic. Our processes can be adapted by other institutions and breast oncology practices in accordance with local conditions and resources, during and beyond the pandemic.

Neoadjuvant chemotherapy in hormone receptor-positive/HER2-negative early breast cancer: When, why and what?

Indication for neoadjuvant chemotherapy (NACT) in HR+/HER2-negative tumors is controversial. Pathological complete response (pCR) rates range from 0 to 18 % while breast-conserving surgery (BCS) is achievable in up to 60 % of tumors. No pathological feature definitely predicts pCR; lobular and molecular luminal A tumors are less likely to achieve pCR although experiencing better outcomes. Luminal B subtype, high proliferation, lack of progesterone receptor, high tumor-infiltrating lymphocytes are positively associated with increased pCR rates but worse outcomes and the prognostic role of pCR is inconsistent across studies. Molecular intrinsic subtyping and genomic signatures appear as more accurate predictors of benefit from NACT, but larger studies are needed. Anthracycline and taxane-based chemotherapy remains the standard NACT; however, CDK 4/6 inhibitors and immune checkpoint inhibitors are under evaluation. In conclusion, NACT may be proposed for luminal tumors requiring downsizing for BCS after multidisciplinary evaluation, provided that other contraindications to BCS are excluded.

When the World Throws You a Curve Ball: Lessons Learned in Breast Cancer Management

In the care of patients with operable breast cancer, there has been a shift toward increasing use of neoadjuvant therapy. There are benefits to neoadjuvant therapy, such as monitoring for response, as well as an increased rate of breast conservation and reduction of potential morbidity associated with breast surgery, including axillary management. Among patients with highly proliferative tumors, such as HER2-positive or triple-negative breast cancer, those with residual disease are at higher risk of recurrence, which informs the recommended systemic therapy in the adjuvant setting. For instance, in patients with residual disease after neoadjuvant chemotherapy and HER2-targeted therapy, there is a role for adjuvant trastuzumab emtansine for those with residual disease at the time of surgery. The same holds true regarding the role of adjuvant capecitabine in patients with residual disease after neoadjuvant chemotherapy. With the added complexities of treating patients in the era of the COVID-19 outbreak, additional considerations are critical, including initiation of surgery within an appropriate time from completion of neoadjuvant therapy. National consensus guidelines on time to surgery must be developed to improve measurement and comparison across systems. In addition, there is emerging radiation treatment management research addressing a number of factors, including hypofractionation, role of proton beam therapy, safe omission of radiotherapy, and preoperative radiotherapy with or without drug combination. In this article, the multidisciplinary approach of treating patients with operable breast cancer is highlighted, with updates and future considerations described.

Disease recurrence and oncological outcome of patients treated surgically with curative intent for estrogen receptor positive, lymph node negative breast cancer

BACKGROUND

The molecular era has identified four breast cancer subtypes. Luminal A breast cancer (LABC) is defined by estrogen-receptor positive (ER+), progesterone-receptor positive (PgR+) and human epidermal growth factor receptor-2 negative (HER2-) tumours; these cancers are the most common and carry favourable prognoses.

AIMS

To describe clinicopathologic features, oncological outcome and relapse patterns in LABC.

METHODS

Consecutive female patients diagnosed with ER/PgR+/HER2-, lymph node negative (LN-) breast cancer between 2005 and 2015 were included. Clinicopathological and recurrence data was recorded using descriptive statistics. Oncological outcome was determined using Kaplan-Meier and Cox-regression analyses.

RESULTS

Analysis was performed for 849 patients with median follow-up of 102.1 months. Mean disease-free (DFS) and overall survival (OS) were 85.8% and 91.8%. Seventy patients died during this study (8.2%), while 58 patients had recurrence; 7 had local recurrence (0.8%) and 51 had distant recurrence (DDR) (6.0%). Patients developing DDR were likely to be postmenopausal (P = 0.028), present symptomatically (P < 0.001) and have larger tumours (P < 0.001). The mean time to DDR was 65.7 months, with fatal recurrence occurring in 66.6% of patients with DDR (34/51). Systemic chemotherapy prescription did not influence DDR (P = 0.053). Age >65 (hazards ratio (HR):1.66, 95% Confidence Interval (CI):1.07-2.55, P = 0.022), presenting symptomatically (HR:2.28, 95%CI:1.21-4.29, P = 0.011) and tumour size >20 mm (HR:1.81, 95%CI:1.25-2.62, P = 0.002) predicted DFS, while age>65 (HR:2.60, 95%CI:1.49-4.53, P = 0.001) and being postmenopausal at diagnosis (HR:3.13, 95%CI:1.19-8.22, P = 0.020) predicted OS.

CONCLUSION

Our series demonstrated excellent survival outcomes for patients diagnosed with LN- LABC after almost a decade of follow-up. However, following DDR, fatal progression is often imminent.

Neoadjuvant Chemotherapy, Endocrine Therapy, and Targeted Therapy for Breast Cancer: ASCO Guideline

PURPOSE

To develop guideline recommendations concerning optimal neoadjuvant therapy for breast cancer.

METHODS

ASCO convened an Expert Panel to conduct a systematic review of the literature on neoadjuvant therapy for breast cancer and provide recommended care options.

RESULTS

A total of 41 articles met eligibility criteria and form the evidentiary basis for the guideline recommendations.

RECOMMENDATIONS

Patients undergoing neoadjuvant therapy should be managed by a multidisciplinary care team. Appropriate candidates for neoadjuvant therapy include patients with inflammatory breast cancer and those in whom residual disease may prompt a change in therapy. Neoadjuvant therapy can also be used to reduce the extent of local therapy or reduce delays in initiating therapy. Although tumor histology, grade, stage, and estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2) expression should routinely be used to guide clinical decisions, there is insufficient evidence to support the use of other markers or genomic profiles. Patients with triple-negative breast cancer (TNBC) who have clinically node-positive and/or at least T1c disease should be offered an anthracycline- and taxane-containing regimen; those with cT1a or cT1bN0 TNBC should not routinely be offered neoadjuvant therapy. Carboplatin may be offered to patients with TNBC to increase pathologic complete response. There is currently insufficient evidence to support adding immune checkpoint inhibitors to standard chemotherapy. In patients with hormone receptor (HR)-positive (HR-positive), HER2-negative tumors, neoadjuvant chemotherapy can be used when a treatment decision can be made without surgical information. Among postmenopausal patients with HR-positive, HER2-negative disease, hormone therapy can be used to downstage disease. Patients with node-positive or high-risk node-negative, HER2-positive disease should be offered neoadjuvant therapy in combination with anti-HER2-positive therapy. Patients with T1aN0 and T1bN0, HER2-positive disease should not be routinely offered neoadjuvant therapy.Additional information is available at www.asco.org/breast-cancer-guidelines.

Selection of neoadjuvant treatment based on the 21-GENE test results in luminal breast cancer

Neoadjuvant chemotherapy (NAC) is an optimal option in early breast cancer, but in ER-positive/HER2-negative (luminal) is still controversial, although a survival benefit has recently been observed when a histological response by Symmans’ method type 0 or I is achieved. The 21-gene Oncotype DX Breast Recurrence Score® assay (Oncotype DX®) is a validated test to assess the survival benefit of adjuvant chemotherapy in these patients but its role in the neoadjuvant setting is less established. We analyzed the results of the Oncotype DX® test in a cohort of 122 consecutive patients selected to receive NAC based on classical clinicopathological parameters and the correlation between the Oncotype DX® results and the pathological response assessed by Symmans’ method. Median age was 56.5 (range 31–84) years. Initial tumor size was T1 (<20 mm) in 46 patients (37.7%), 57 (46.7%) had a T2 tumor (20–50 mm), and 19 (15.6%) had a tumor size more than 50 mm. 59 (48.4%) had axillary node involvement. The median expression estrogen and progesteron receptors by immunohistochemistry was 280 and 120 respectively and median Ki67 index was 28%. The Recurrence Score (RS) results were <11 in 21 patients (17.2%) patients, RS 11 to 25 in 58 (47.5%), and RS > 25 in 43 (35.2%). Considering the Oncotype DX test results, neoadjuvant chemotherapy was administered to 60 patients (49%), 11 (9%) received adjuvant chemotherapy and 51 (42%) no chemotherapy. Testing with the assay has therefore led to 42% fewer chemotherapy treatments. Among 60 patients receiving NAC, pathologic response was achieved for 5 patients (8.3%) with RCB-0 and 15 RCB-1 (25%). We did not find any pathological response RCB-0 and RCB-I in the 20 patients who received NAC and had a Recurrence Score result <21 for the premenopausal group, or a RS result <25 for the postmenopausal group. For patients with highest Recurrence Score results (RS > 21 or 25 according to menopausal status) it was 12% (5/40) RCB-0 and 40% (16/40) RCB-I.

Conclusions

The Oncotype DX test could be a useful tool to select patients candidates for neoadjuvant chemotherapy in luminal breast cancer. Neoadjuvant chemotherapy could be avoided in 42% of patients. We found a correlation between Recurrence Score results and pathological response with 14% of RCB-0 and a total of 47% of significant pathological response type RCB-0 and RCB-I in patients with highest Recurrence Score results. Interestingly, patients with a Recurrence Score result inferior to 32 did not get any histological response type 0 and only 5% RCB-I.

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All comments are reviewed in the main manuscript text.

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We have introduced changes in tables and Figures according Editor′s comments.

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It is an academic study and we don′t received any founding and we appreciate all patients who participated.

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

INTRODUCTION

Oncotype DX^® recurrence score (RS) is well-recognized for guiding decision making in adjuvant chemotherapy; however, the predictive capability of this genomic assay in determining axillary response to neoadjuvant chemotherapy (NCT) has not been established.

METHODS

Using the National Cancer Data Base (NCDB), we identified patients diagnosed with T1-T2, clinically N1/N2, estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER +/HER2 -) invasive ductal carcinoma of the breast between 2010 and 2015. Patients with an Oncotype DX^® RS who received NCT were included. RS was defined as low (< 18), intermediate (18-30), or high (> 30). Unadjusted and adjusted analyses were performed to determine the association between axillary pathologic complete response (pCR) and RS.

RESULTS

This study included a total of 158 women. RS was low in 56 (35.4%) patients, intermediate in 62 (39.2%) patients, and high in 40 (25.3%) patients. The majority of patients presented with clinical N1 disease (89.2%). Axillary pCR was achieved in 23 (14.6%) patients. When stratifying patients with axillary pCR by RS, 11 (47.8%) patients had a high RS, 6 (26.1%) patients had an intermediate RS, and 6 (26.1%) patients had a low RS. Comparing cohorts by RS, 27.5% of patients with high RS tumors had an axillary pCR, compared with only 9.7% in the intermediate RS group, and 10.7% in the low RS group (p = 0.0268).

CONCLUSION

Our findings demonstrate that Oncotype DX^® RS is an independent predictor of axillary pCR in patients with ER +/HER2 - breast cancers receiving NCT. A greater proportion of patients with a high RS achieved axillary pCR. These results support Oncotype DX^® as a tool to improve clinical decision making in axillary management.

Magee Equations™ and response to neoadjuvant chemotherapy in ER+/HER2-negative breast cancer: a multi-institutional study

Magee Equations™ (ME) are multivariable models that can estimate oncotype DX^® recurrence score. One of the equations, Magee Equation 3 (ME3) which utilizes only semi-quantitative receptor results has been shown to provide chemopredictive value in the neoadjuvant setting in a single institutional study. This multi-institutional study (seven institutions contributed cases) was undertaken to examine the validity of ME3 in predicting response to neoadjuvant chemotherapy in estrogen receptor positive, HER2-negative breast cancers. Stage IV cases were excluded. The primary endpoint was the pathologic complete response (pCR) rate in different categories of ME3 scores calculated based on receptor results in the pre-therapy core biopsy. A total of 166 cases met the inclusion criteria. The patient age ranged from 24 to 83 years (median 53 years). The average pre-therapy tumor size was 3.9 cm, and axillary lymph nodes were confirmed positive by pre-therapy core biopsy in 85 of 166 cases (51%). The pCR rate according to ME3 scores was 0% (0 of 64) in ME3 < 18, 0% (0 of 46) in ME3 18-25, 14% (3 of 21) in ME3 > 25 to <31, and 40% (14 of 35) in ME3 score 31 or higher (p value: <0.0001). There were no distant recurrences and no deaths in the 17 patients with pCR. In the remaining 149 cases with residual disease, ME3 score of >25 was significantly associated with shorter distant recurrence-free survival and showed a trend for shorter breast cancer-specific survival. The results of this multi-institutional study are similar to previously published data from a single institution (PMID: 28548119) and confirm the chemo-predictive value of ME3 in the neoadjuvant setting. In addition, ME3 may provide prognostic information in patients with residual disease which should be further evaluated.