Post-neoadjuvant treatment and the management of residual disease in breast cancer: state of the art and perspectives

Investigating the Association Between Type 2 Diabetes Mellitus and Pathological Responses Among Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

INTRODUCTION

The relationship between type 2 diabetes mellitus (T2DM) and pathological responses after neoadjuvant chemotherapy (NACT) is controversial. In this study, we aim to determine the association of pathological responses in breast cancer women with T2DM after receiving NACT.

METHODS

Medical records of breast cancer women with T2DM who received NACT from January 2016 to January 2021 at the medical center in the Gujranwala Institute of Nuclear Medicine and Radiotherapy, Pakistan, were identified and retrieved retrospectively. Variables, including pathological responses, diabetes status, and other clinical data, were collected. Patients were grouped as diabetic and nondiabetic based on the doctor's diagnosis or the diabetic's medication history recorded upon the breast cancer diagnosis. Factors influencing the pathological complete response (pCR) were determined using multivariate logistic regression utilizing IBM SPSS Statistics (version 20).

RESULTS

A total of 1372 patient files who received NACT and breast cancer surgery from January 2016 to January 2021 were selected. Out of 1372 breast cancer women receiving NACT, 345 (25.1%) had pre-existing diabetes, while 1027 (74.85%) were without pre-existing diabetes. The most common molecular subtypes of breast cancer were luminal A and B. Two hundred fifty-eight patients (18.8%) had a pCR after receiving NACT. The pCR in diabetic patients was 3.9%, and in nondiabetes, 14.9%. Most women had a pathological partial response (pPR) after the NACT 672 (48.9%). The pPR in diabetic patients was 11.0%, and in nondiabetic patients, it was 38.0%. In nondiabetics, the odds of achieving pPR increase more than pathological no response after the NACT with odd ratio: 1.71 (95% confidence interval: 1.24-2.37). The probability of pCR in patients with luminal B was 1.67 times higher than that in patients with triple-negative breast cancer with odd ratio: 1.67, 95% confidence interval (1.00-2.79), P = 0.05.

CONCLUSIONS

The results of the study show that T2DM may have an adverse impact on pCR and pPR following NACT and surgery. Further investigation is needed to explore how changes in blood glucose levels over time impact pathological responses.

TROPION-Breast03: a randomized phase III global trial of datopotamab deruxtecan ± durvalumab in patients with triple-negative breast cancer and residual invasive disease at surgical resection after neoadjuvant therapy

Background

Despite advances in the treatment of early triple-negative breast cancer (TNBC), patients with residual invasive disease after neoadjuvant therapy have a high risk of disease recurrence and worse survival outcomes than those who have pathological complete response (pCR). Improving outcomes in early TNBC remains an unmet need requiring new adjuvant treatment approaches. Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugate comprising a humanized anti-trophoblast cell-surface antigen 2 immunoglobulin G1 (IgG1) monoclonal antibody attached via a plasma-stable, cleavable linker to a potent topoisomerase I inhibitor payload, with activity observed in advanced TNBC.

Objectives

TROPION-Breast03 is an ongoing phase III study evaluating the efficacy and safety of Dato-DXd alone or combined with durvalumab versus standard-of-care therapy as adjuvant treatment in patients with stage I-III TNBC with residual invasive disease at surgical resection following neoadjuvant treatment.

Methods and design

Eligible patients, aged ⩾18 years, will be randomized in a 2:1:2 ratio to receive Dato-DXd [6 mg/kg intravenously (IV) every 3 weeks (Q3W); eight cycles] and durvalumab (1120 mg IV Q3W; nine cycles), Dato-DXd monotherapy (6 mg/kg IV Q3W), or investigator's choice of therapy (ICT; capecitabine, pembrolizumab, or capecitabine and pembrolizumab). The primary endpoint is invasive disease-free survival (iDFS) for Dato-DXd and durvalumab versus ICT. Key secondary endpoints include safety, distant disease-free survival, and overall survival for Dato-DXd and durvalumab versus ICT and iDFS for Dato-DXd monotherapy versus ICT.

Ethics

TROPION-Breast03 will be approved by the independent ethics committees or institutional review boards at each study site. All study participants will provide written informed consent.

Discussion

TROPION-Breast03 will help define the potential role of Dato-DXd in the treatment of patients with early-stage TNBC who do not have pCR after neoadjuvant therapy.

Trial registration

ClinicalTrials.gov identifier: NCT05629585 (registration date: 29 November 2022).

Axillary lymph node dissection in triple-negative or HER2-positive breast cancer patients with clinical N2 achieving pathological complete response after neoadjuvant therapy: Is it necessary?

AIM

This study aims to identify suitable candidates for axillary sentinel lymph node biopsy (SLNB) or targeted axillary dissection (TAD) among clinical N2 (cN2) triple-negative (TN) or HER2 positive (HER2+）breast cancer patients following neoadjuvant therapy（NAT）.

BACKGROUND

Despite the substantial axillary burden in cN2 breast cancer patients, high pathological response rates can be achieved with NAT in TN or HER2+ subtypes, thus enabling potential downstaging of axillary surgery.

METHODS

A retrospective analysis was conducted on data from the CSBrS-012 study, screening 709 patients with initial cN2, either HER2+ or TN subtype, from January 1, 2010 to December 31, 2020. The correlation between axillary pathologic complete response (pCR) (yPN0) and breast pCR was examined.

RESULTS

Among the 177 cN2 patients who achieved breast pCR through NAT, 138 (78.0 %) also achieved axillary pCR. However, in the 532 initial clinical N2 patients who did not achieve breast pCR, residual axillary lymph node metastasis persisted in 77.4 % (412/532) of cases. The relative risk of residual axillary lymph node metastasis in patients who did not achieve breast pCR was 12.4 (8.1-19.1), compared to those who did achieve breast pCR, P < 0.001.

CONCLUSION

For cN2 TN or HER2+ breast cancer patients who achieve breast pCR following NAT, consideration could be given to downstaging and performing an axillary SLNB or TAD.

Low RNA disruption during neoadjuvant chemotherapy predicts pathologic complete response absence in patients with breast cancer

In previously reported retrospective studies, high tumor RNA disruption during neoadjuvant chemotherapy predicted for post-treatment pathologic complete response (pCR) and improved disease-free survival at definitive surgery for primary early breast cancer. The BREVITY (Breast Cancer Response Evaluation for Individualized Therapy) prospective clinical trial (NCT03524430) seeks to validate these prior findings. Here we report training set (Phase I) findings, including determination of RNA disruption index (RDI) cut points for outcome prediction in the subsequent validation set (Phase II; 454 patients). In 80 patients of the training set, maximum tumor RDI values for biopsies obtained during neoadjuvant chemotherapy were significantly higher in pCR responders than in patients without pCR post-treatment (P = .008). Moreover, maximum tumor RDI values ≤3.7 during treatment predicted for a lack of pCR at surgery (negative predictive value = 93.3%). These findings support the prospect that on-treatment tumor RNA disruption assessments may effectively predict post-surgery outcome, possibly permitting treatment optimization.

The residual cancer burden index as a valid prognostic indicator in breast cancer after neoadjuvant chemotherapy

PURPOSE

The residual cancer burden index (RCB) was proposed as a response evaluation criterion in breast cancer patients treated with Neoadjuvant Chemotherapy (NAC). This study evaluated the relevance of RCB with replase-free survival (RFS).

METHODS

The clinical data of 254 breast cancer patients who received NAC between 2016 and 2020 were retrospectively collected. The relationship between clinicopathologic factors and RFS was evaluated using Cox proportional hazards regression models. RFS estimates were determined by Kaplan-Meier(K-M) analysis and compared using the log-rank test. Multivariate logistic regression analysis was used to evaluate the risk factors associated with RCB. Receiver operating characteristic (ROC) curves showed the potential of the RCB and MP grading systems as biomarkers for RFS.

RESULTS

At a median follow-up of 52 months, 59 patients(23.23%) developed relapse. Multivariate Cox regression showed that older age (P = 0.022), high Pathologic T stage after NAC (P = 0.023) and a high RCB score(P = 0.003) were risk factors for relapse. The outcomes of the multivariate logistic analysis indicated that RCB 0 (pathologic complete response [pCR]) was associated with HER2-positive patients (P = 0.002) and triple-negative breast cancer (TNBC) patients (P = 0.013). In addition, the RCB and MP scoring systems served as prognostic markers for patients who received NAC, and their area under curves (AUCs) were 0.691 and 0.342, respectively.

CONCLUSION

These data suggest that RCB can be equally applied to predict RFS in Chinese patients with NAC. The application of RCB may help guide the selection of treatment strategies.

Distinct Prognosis of Minimal Residual Disease According to Breast Cancer Subtype in Patients with Breast or Nodal Pathologic Complete Response After Neoadjuvant Chemotherapy

PURPOSE

Few studies have reported on patient prognosis according to residual cancer burden after neoadjuvant chemotherapy (NAC). Herein, we evaluated the survival of patients based on residual disease after NAC to identify subpopulations with distinct prognoses.

METHODS

We retrospectively reviewed 728 patients treated with NAC from 2010 to 2017. Patients were divided into four subgroups depending on post-surgical residual disease according to the staging system: pathological complete response (pCR) (ypT0/TisN0), minimal residual disease (MRD) (ypT1mi/T1aN0 or ypT0/Tis ypN0i+/N1mic), node-only pCR (≥ ypT1b ypN0), and breast-only pCR (ypT0/Tis ≥ ypN1a). Clinicopathological characteristics and survival outcomes were analyzed by adjusting for factors affecting survival.

RESULTS

Overall, 50.4% (n = 367) of patients achieved pCR, with the MRD group accounting for 16.5% (n = 120). Although age and clinical stage were not different among the study groups, histologic grade, subtypes, chemotherapy response, and local treatment showed differences. Event-free survival (EFS) and overall survival (OS) demonstrated no significant difference between the pCR and MRD groups. In the multivariate analysis, pCR status was the only significant factor in EFS, and no statistical difference was noted between the pCR and MRD groups. However, clinical stage, pCR status, and subtype significantly affected the OS. MRD showed favorable outcomes in terms of both EFS and OS in all subtypes, except for those with triple-negative breast cancer (TNBC).

CONCLUSION

Patients with MRD showed outcomes comparable to those of patients who achieved pCR and may be candidates for de-escalation of post-NAC treatment, except for those with a TNBC subtype.

Adjuvant Targeted Therapy in Solid Cancers: Pioneers and New Glories

Targeted therapy (TT) has revolutionized cancer treatment, successfully applied in various settings. Adjuvant TT in resected early-stage gastrointestinal stromal tumors (GIST), melanoma, non-small cell lung cancer (NSCLC), and breast cancer has led to practice-changing achievements. In particular, standard treatments include BRAF inhibitors for melanoma, osimertinib for NSCLC, hormone therapy or HER2 TT for breast cancer, and imatinib for GIST. Despite the undeniable benefit derived from adjuvant TT, the optimal duration of TT and the appropriate managing of the relapse remain open questions. Furthermore, neoadjuvant TT is emerging as valuable, particularly in breast cancer, and ongoing studies evaluate TT in the perioperative setting for early-stage NSCLC. In this review, we aim to collect and describe the large amount of data available in the literature about adjuvant TT across different histologies, focusing on epidemiology, major advances, and future directions.

An Innovative Scoring System to Select the Optimal Surgery in Breast Cancer after Neoadjuvant Chemotherapy

INTRODUCTION

The selection of surgery post-neoadjuvant chemotherapy (NACT) is difficult and based on surgeons' expertise. The aim of this study was to create a post-NEoadjuvant Score System (pNESSy) to choose surgery, optimizing oncological and aesthetical outcomes.

METHODS

Patients (stage I-III) underwent surgery post-NACT (breast-conserving surgery (BCS), oncoplastic surgery (OPS), and conservative mastectomy (CMR) were included. Data selected were BRCA mutation, ptosis, breast volume, radiological response, MRI, and mammography pre- and post-NACT prediction of excised breast area. pNESSy was created using the association between these data and surgery. Area under the curve (AUC) was assessed. Patients were divided into groups according to correspondence (G1) or discrepancy (G2) between score and surgery; oncological and aesthetic outcomes were analyzed.

RESULTS

A total of 255 patients were included (118 BCS, 49 OPS, 88 CMR). pNESSy between 6.896-8.724 was predictive for BCS, 8.725-9.375 for OPS, and 9.376-14.245 for CMR; AUC was, respectively, 0.835, 0.766, and 0.825. G1 presented a lower incidence of involved margins (5-14.7%; p = 0.010), a better locoregional disease-free survival (98.8-88.9%; p < 0.001) and a better overall survival (96.1-86.5%; p = 0.017), and a better satisfaction with breasts (39.8-27.5%; p = 0.017) and physical wellbeing (93.5-73.6%; p = 0.001).

CONCLUSION

A score system based on clinical and radiological features was created to select the optimal surgery post-NACT and improve oncological and aesthetic outcomes.

Genomic signature to guide adjuvant chemotherapy treatment decisions for early breast cancer patients in France: a cost-effectiveness analysis

Introduction

Chemotherapy (CT) is commonly used as an adjuvant treatment for women with early breast cancer (BC). However, not all patients benefit from CT, while all are exposed to its short- and long-term toxicity. The Oncotype DX^® test assesses cancer-related gene expression to estimate the risk of BC recurrence and predict the benefit of chemotherapy. The aim of this study was to estimate, from the French National Health Insurance (NHI) perspective, the cost-effectiveness of the Oncotype DX^® test compared to standard of care (SoC; involving clinicopathological risk assessment only) among women with early, hormone receptor-positive, human epidermal growth factor receptor 2-negative BC considered at high clinicopathological risk of recurrence.

Methods

Clinical outcomes and costs were estimated over a lifetime horizon based on a two-component model that comprised a short-term decision tree representing the adjuvant treatment choice guided by the therapeutic decision support strategy (Oncotype DX^® test or SoC) and a Markov model to capture long-term outcomes.

Results

In the base case, the Oncotype DX^® test reduced CT use by 55.2% and resulted in 0.337 incremental quality-adjusted life-years gained and cost savings of €3,412 per patient, compared with SoC. Being more effective and less costly than SoC, Oncotype DX^® testing was the dominant strategy.

Discussion

Widespread implementation of Oncotype DX^® testing would improve patient care, provide equitable access to more personalized medicine, and bring cost savings to the health system.

Correlation of Before and After Invasive Breast Cancer Neoadjuvant Chemotherapy for NFkB, Cyclin D1, and Survivin Expression

Background & Objective

Patients undergoing neoadjuvant chemotherapy (NC) for invasive breast cancer (IBC) therapy need biomarkers to track their progress. Because of the relationship between NFkB, Survivin, and Cyclin D1 with NC resistance, the different expression levels of each of these biomarkers can be different between pre- and post-NC in IBC. However, no research has examined the correlation between these biomarkers before and after the NC expression. This study aimed to determine the correlation among them.

Methods

Biomarkers expression (low and high) was used to classify 30 samples. ER, PR, HER2, Ki-67 status, tumor grade, age, and NC response were assessed. The amounts of Survivin, Cyclin D1, and NFkB were evaluated using immunohistochemistry, and the samples were classified based on the cut-off. Chi-square and linear regression were used to evaluate the data.

Results

No significant association was found with the changes in the expression of Survivin, Cyclin D1, and NFkB, both before and after the NC. Significant moderate correlations were shown between before and after the NC Survivin expression (r = 0.513) and Cyclin D1 expression (r = 0.543). The correlation between expression of NFkB before and after the NC was not significant.

Conclusion

The high potential of these proteins as prognostic indicators was demonstrated by the strong positive association between the expression of Survivin and Cyclin D1 before and after the NC. This upregulation of biomarkers indicates chemoresistance in developing IBC in the presence of NC.

Real‑world data indicated that neoadjuvant chemotherapy alone was associated with a higher risk of tumor recurrence in high‑risk breast cancer subgroup patients

Numerous clinical trials have reported equal effects of tumor control between neoadjuvant chemotherapy (NAC) and adjuvant chemotherapy (AC) in patients with breast cancer (BC). However, this conclusion has not been verified in practice. The present retrospective study evaluated if there were different risk profiles for NAC, AC and their combinative modes on disease-free survival (DFS) in patients with BC using real-world data. All women with primary unilateral Stage I-III BC and first recurrence in 2008-2018 at The Fourth Hospital of Hebei Medical University were retrospectively identified for enrollment. The four modes of chemotherapy administered for primary BC were classified as 'None', 'NAC only', 'NAC+AC' and 'AC only'. One multivariate Cox model was used to estimate the adjusted Hazard Ratio (HR) and P-value. Covariates included age, Easter Cooperative Oncology Group grade, T stage, N stage, pathology, grade, lymphovascular invasion (LVI), BC subtype, number of chemotherapy cycles and other therapies. Amongst 637 patients, who had a mean age of 48.2 years at BC diagnosis and 50.9 years at recurrence, the median DFS by the 'None' (n=27), 'NAC only' (n=47), 'NAC+AC' (n=118) and 'AC only' (n=445) modes were 31.4, 16.6, 22.6 and 28.4 months (P<0.001), respectively. Compared with the 'AC only', adjusted HR (P-value) of the 'None', 'NAC only' and 'NAC+AC' modes on tumor recurrence were 1.182 (0.551), 1.481 (0.037) and 1.102 (0.523), respectively. The adjusted HR of 'NAC only' vs. 'AC only' modes were 1.448 (P=0.157) for locoregional recurrence and 2.675 (P=0.003) for distant recurrence. Stratified analyses further indicated that the 'NAC only' mode was associated with a higher recurrence risk in T3-4, N2-3, LVI-positive, or HER2-negative subgroup patients. In conclusion, NAC alone was associated with a higher risk of tumor recurrence in high-risk BC subgroup patients in real-world data. Patient selection of chemotherapy mode was involved in practice but could not fully explain this finding. The 'inadequate' NAC was highly likely to have accounted for this observation.

Narrative review on the role of immunotherapy in early triple negative breast cancer: unveiling opportunities and overcoming challenges

Background and Objective

Triple negative breast cancer (TNBC) represents a highly aggressive breast cancer subtype, historically managed with chemotherapy regimens predominantly involving anthracyclines and taxanes, yielding unfavorable prognoses. This review endeavors to offer a thorough examination of the present state of treatment strategies for early stage triple negative breast cancer (eTNBC), with a particular emphasis on immunotherapy modalities, combination therapies, predictive biomarkers, and ongoing clinical trials. The principal aim of this review is to meticulously assess the available literature, ascertain significant discoveries, and engage in discussions regarding their potential implications for future research endeavors, clinical applications, and policy formulation.

Methods

This review was conducted using PubMed and Google Scholar databases, with the latest update performed in March 2023. The search strategy was designed to ensure a comprehensive analysis of the literature, with a focus on recent advancements.

Key Content and Findings

We critically assess the current eTNBC treatment landscape, covering efficacy and limitations of monotherapy, combination therapies, and predictive biomarkers. We highlight promising results from recent trials, address controversies surrounding chemotherapy, and explore optimal approaches for adjuvant and neoadjuvant therapy (NAT). Insights into personalized treatment strategies, ongoing trials, and future perspectives are provided, advancing our understanding of therapeutic options for eTNBC.

Conclusions

Through a comprehensive analysis of the literature, this review highlights the potential of immunotherapy, particularly in combination with chemotherapy, as a promising approach for treating eTNBC. However, further research is warranted to optimize treatment strategies, refine patient selection criteria, and identify reliable biomarkers for predicting response to immune checkpoint inhibitors (ICIs). The findings of this review hold significant implications for future research, clinical practice, and policy-making, offering valuable insights into the current challenges and advancements in eTNBC treatment. Ultimately, this knowledge can contribute to improved patient outcomes, enhanced quality of life, and the development of more effective therapeutic approaches for eTNBC.

Identifying biomarkers of differential chemotherapy response in TNBC patient-derived xenografts with a CTD/WGCNA approach

Although systemic chemotherapy remains the standard of care for TNBC, even combination chemotherapy is often ineffective. The identification of biomarkers for differential chemotherapy response would allow for the selection of responsive patients, thus maximizing efficacy and minimizing toxicities. Here, we leverage TNBC PDXs to identify biomarkers of response. To demonstrate their ability to function as a preclinical cohort, PDXs were characterized using DNA sequencing, transcriptomics, and proteomics to show consistency with clinical samples. We then developed a network-based approach (CTD/WGCNA) to identify biomarkers of response to carboplatin (MSI1, TMSB15A, ARHGDIB, GGT1, SV2A, SEC14L2, SERPINI1, ADAMTS20, DGKQ) and docetaxel (c, MAGED4, CERS1, ST8SIA2, KIF24, PARPBP). CTD/WGCNA multigene biomarkers are predictive in PDX datasets (RNAseq and Affymetrix) for both taxane- (docetaxel or paclitaxel) and platinum-based (carboplatin or cisplatin) response, thereby demonstrating cross-expression platform and cross-drug class robustness. These biomarkers were also predictive in clinical datasets, thus demonstrating translational potential.

Research Status of Systemic Adjuvant Therapy for Early Breast Cancer

Breast cancer has surpassed lung cancer as the most common cause of cancer deaths, worldwide. Early breast cancers are treatment sensitive and patients under standardized treatment have prolonged. Breast cancer treatment has significantly evolved from the conventional surgical approach and radiotherapy to local and systemic adjuvant therapies. Though localized breast cancers are clinically manageable, distant recurrence is a cause of morbid concern. Adjuvant systemic therapy is effective in both distant and local recurrences and hence gained significant attention. Early breast cancer prognosis has greatly improved in the past 3 decades with reduced mortality rates due to the widespread use of adjuvant therapy. It can markedly increase the cure rate of breast cancers, and postoperative adjuvant therapy became a part of comprehensive breast cancer treatment. Further research to understand the early breast cancer characteristics could expand the treatment modalities that can improve the outcomes and survival benefits of breast cancer patients.

Treatment Strategies for Residual Disease following Neoadjuvant Chemotherapy in Patients with Early-Stage Breast Cancer

Breast cancer continues to be the most diagnosed cancer among women worldwide. Neoadjuvant chemotherapy is the standard of care for breast cancer patients with locally advanced disease and patients with poor pathological features, such as triple-negative (TN) or human epidermal growth factor receptor-2 (HER2)-positive subtypes. Neoadjuvant therapy offers several advantages, including better surgical outcomes, early systemic treatment for micro-metastases, and accurate tumor biology and chemosensitivity assessment. Multiple studies have shown that achieving pathological complete response (pCR) following neoadjuvant chemotherapy is associated with better prognosis and better treatment outcomes; almost half of such patients may fail to achieve pCR. Tumor proliferative index, hormone receptor (HR) status, and HER2 expression are the major predictors of pCR. Strategies to improve pCR have been dependent on augmenting neoadjuvant chemotherapy with the addition of taxanes and dual anti-HER2 targeted therapy in patients with HER2-positive tumor, and more recently, immunotherapy for patients with TN disease. The clinical management of patients with residual disease following neoadjuvant chemotherapy varies and depends mostly on the level of HR expression and HER2 status. Recent data have suggested that switching trastuzumab to trastuzumab-emtansine (T-DM1) in patients with HER2-positive disease and the addition of capecitabine for patients with HER2-negative and HR-negative subtype is associated with a better outcome; both strategies are incorporated into current clinical practice guidelines. This paper reviews available and ongoing studies addressing strategies to better manage patients who continue to have residual disease following neoadjuvant chemotherapy.

Evaluation of different imaging modalities for axillary lymph node staging in breast cancer patients to provide a personalized and optimized therapy algorithm

PURPOSE

The reliable detection of tumor-infiltrated axillary lymph nodes for breast cancer [BC] patients plays a decisive role in further therapy. We aimed to find out whether cross-sectional imaging techniques could improve sensitivity for pretherapeutic axillary staging in nodal-positive BC patients compared to conventional imaging such as mammography and sonography.

METHODS

Data for breast cancer patients with tumor-infiltrated axillary lymph nodes having received surgery between 2014 and 2020 were included in this study. All examinations (sonography, mammography, computed tomography [CT] and magnetic resonance imaging [MRI]) were interpreted by board-certified specialists in radiology. The sensitivity of different imaging modalities was calculated, and binary logistic regression analyses were performed to detect variables influencing the detection of positive lymph nodes.

RESULTS

All included 382 breast cancer patients had received conventional imaging, while 52.61% of the patients had received cross-sectional imaging. The sensitivity of the combination of all imaging modalities was 68.89%. The combination of MRI and CT showed 63.83% and the combination of sonography and mammography showed 36.11% sensitivity.

CONCLUSION

We could demonstrate that cross-sectional imaging can improve the sensitivity of the detection of tumor-infiltrated axillary lymph nodes in breast cancer patients. Only the safe detection of these lymph nodes at the time of diagnosis enables the evaluation of the response to neoadjuvant therapy, thereby allowing access to prognosis and improving new post-neoadjuvant therapies.

Accuracy and Limitations of Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy in Breast Cancer Patients with Positive Nodes

Background

Axillary surgical management in patients with node-positive breast cancer at the time of diagnosis converted to negative nodes through neoadjuvant chemotherapy (NAC) remains unclear. Removal of more than two sentinel nodes (SLNs) in these patients may decrease the false negative rate (FNR) of sentinel lymph node biopsies (SLNBs). We aim to analyse the detection rate (DR) and the FNR of SLNB assessment according to the number of SLNs removed.

Methods

A retrospective study was performed from October 2012 to December 2018. Patients with invasive breast cancer who had a clinically node-positive disease at diagnosis and with a complete axillary response after neoadjuvant chemotherapy were selected. Patients included underwent SLNB and axillary lymph node dissection (ALND) after NAC. The SLN was considered positive if any residual disease was detected. Descriptive statistics were used to describe the clinicopathologic features and the results of SLNB and ALND. The DR of SLNB was defined as the number of patients with successful identification of SLN. Presence of residual disease in ALND and negative SLN was considered false negative.

Results

A total of 368 patients with invasive breast cancer who underwent surgery after complete NAC were studied. Of them, 85 patients met the eligibility criteria and were enrolled in the study. The mean age at diagnosis was 50.8 years. Systematic lymphadenectomy was performed in all patients, with an average of 10 lymph nodes removed. The DR of SLNB was 92.9%, and the FNR was 19.1. The median number of SLNs removed was 3, and at least, three SLNs were obtained in 42 patients (53.2%). When at least three sentinel nodes were removed, the FNR decreased to 8.7%.

Conclusions

In this cohort, the SLN assessment was associated with an adequate DR and a high FNR. Removing three or more SLNs decreased the FNR from 19.1% to 8.7%. Complementary approaches may be considered for axillary lymph node staging after neoadjuvant chemotherapy. The study was approved by our institution's ethics committee (Instituto de Investigacion Sanitaria Hospital 12 de Octubre (imas12), Universidad Complutense de Madrid, Madrid, Spain) (https://clinicaltrials.gov/ct2/show/NCEI:20/0048).

A Canadian national guideline on the neoadjuvant treatment of invasive breast cancer, including patient assessment, systemic therapy, and local management principles

Purpose

The neoadjuvant treatment of breast cancer (NABC) is a rapidly changing area that benefits from guidelines integrating evidence with expert consensus to help direct practice. This can optimize patient outcomes by ensuring the appropriate use of evolving neoadjuvant principles.

Methods

An expert panel formulated evidence-based practice recommendations spanning the entire neoadjuvant breast cancer treatment journey. These were sent for practice-based consensus across Canada using the modified Delphi methodology, through a secure online survey. Final recommendations were graded using the GRADE criteria for guidelines. The evidence was reviewed over the course of guideline development to ensure recommendations remained aligned with current relevant data.

Results

Response rate to the online survey was almost 30%; representation was achieved from various medical specialties from both community and academic centres in various Canadian provinces. Two rounds of consensus were required to achieve 80% or higher consensus on 59 final statements. Five additional statements were added to reflect updated evidence but not sent for consensus.

Conclusions

Key highlights of this comprehensive Canadian guideline on NABC include the use of neoadjuvant therapy for early stage triple negative and HER2 positive breast cancer, with subsequent adjuvant treatments for patients with residual disease. The use of molecular signatures, other targeted adjuvant therapies, and optimal response-based local regional management remain actively evolving areas. Many statements had evolving or limited data but still achieved high consensus, demonstrating the utility of such a guideline in helping to unify practice while further evidence evolves in this important area of breast cancer management.

Role and evaluation of pathologic response in early breast cancer specimens after neoadjuvant therapy: consensus statement

Pathologic evaluation of early breast cancer after neoadjuvant therapy is essential to provide prognostic information based on tumor response to treatment (pathologic complete response [pCR] or non-pCR) and to inform therapy decisions after surgery. To harmonize the pathologist’s handling of surgical specimens after neoadjuvant therapy, a panel of experts in breast cancer convened to developed a consensus on six main topics: (1) definition of pCR, (2) required clinical information, (3) gross examination and sampling, (4) microscopic examination, (5) evaluation of lymph node status, and (6) staging of residual breast tumor. The resulting consensus statements reported in this document highlight the role of an accurate evaluation of tumor response and define the minimum requirements to standardize the assessment of breast cancer specimens after neoadjuvant therapy.

Prognostic Impact of Ki-67 Change in Locally Advanced and Early Breast Cancer after Neoadjuvant Chemotherapy: A Single Institution Experience

Systemic neoadjuvant chemotherapy (NCT) is a standard treatment for locally advanced breast cancer (LABC) and for selected early breast cancer (EBC). In these settings, the prognostic and predictive role of Ki-67 before and after NCT is unclear. The aim of our study was to investigate the prognostic role of Ki-67 change in patients not achieving pathological complete response (pCR). We retrospectively analyzed data of patients who did not achieve pCR assessing Ki-67 expression pre- and post-NCT. We stratified three groups: high reduction (>20%), low reduction (1–20%), and no reduction in Ki-67. These groups were correlated with clinical and pathological data by χ2 test. We estimated disease-free survival (DFS) and overall survival (OS) using Kaplan–Meier method, and we adopted univariate and multivariate Cox proportional hazard models. We selected 82 patients from a database of 143 patients, excluding those who were metastatic at diagnosis, achieved pCR, or lack data regarding Ki-67. Median age at diagnosis was 54 years (range 30–75); 51 patients were Luminal B, 10 human epidermal growth factor receptor 2 (HER-2) enriched, and 21 triple negative. A significant correlation between high Ki-67 reduction and luminal B HER-2-negative subtype was observed (p = 0,0035). The change in Ki-67 was significantly associated with DFS (p = 0,0596) and OS (p = 0,0120), also at multivariate analysis (p = 0,0256 for DFS; p = 0,0093 for OS). In particular, as compared to patients with low/no reduction of Ki-67, those with high Ki-67 reduction (>20%) after NCT showed better survival (60% vs. 56% vs. 83% after 5 years from diagnosis, respectively; p = 0.01). In conclusion, in our study, Ki-67 change showed a significant prognostic role in breast cancer patients treated with NCT who did not achieve pCR. Crucially, Ki-67 < 20% identifies a high-risk population that may be eligible for clinical trials with novel therapeutic interventions in adjuvant setting.

Expression of E26 transformation specific-1 (ETS-1) in tumour-infiltrating lymphocytes (TILs) is adverse prognostic factor in invasive breast cancer

AIM OF THE STUDY

The microenvironment depicts the relationship between tumour cells and immune response, and every insight into stromal lymphocytes could contribute to explain their role and activity. E26 transformation specific-1 (ETS-1) is a transcription factor that is active in cell proliferation. We analysed its immunohistochemical expression in tumour infiltrating lymphocytes (TILs) in invasive breast cancer and correlated its immunohistochemical score (IHS) to traditional predictive and prognostic factors and survival.

MATERIALS AND METHODS

The sample contains data of 121 patients with invasive breast cancer, not otherwise specified (NOS) who underwent mammectomy and lymphadenectomy in 2002 at the Clinical Hospital Centre Zagreb, Croatia. Paraffin blocks of the tumour tissue were collected from the pathological archive. Three representative areas of every patient were chosen and multiple tissue samples were made. Immunohistochemical staining with rabbit anti-ETS-1 (Novocastra, UK) and the ABC method was performed on a DAKO Autostainer. The expression of ETS-1 in stromal TILs was analysed on an Olympus 41 microscope. The IHS score was calculated and correlated with clinical and pathological parameters, as well as disease-free survival (DFS) and overall survival (OS).

RESULTS

In almost all patients (95%), some expression of ETS-1 in TILs was found. A moderate/high score of ETS-1 correlated with larger tumour size and higher histological grade, high proliferation index and low progesterone receptors (PgR). The patients with moderate/high ETS-1 expression in TILs had shorter DFS than patients with weak/negative ETS-1 expression.

CONCLUSION

In invasive breast cancer NOS, expression of ETS-1 in TILs is an adverse prognostic factor.

Circulating tumor DNA and magnetic resonance imaging to predict neoadjuvant chemotherapy response and recurrence risk

We investigated whether serial measurements of circulating tumor DNA (ctDNA) and functional tumor volume (FTV) by magnetic resonance imaging (MRI) can be combined to improve prediction of pathologic complete response (pCR) and estimation of recurrence risk in early breast cancer patients treated with neoadjuvant chemotherapy (NAC). We examined correlations between ctDNA and FTV, evaluated the additive value of ctDNA to FTV-based predictors of pCR using area under the curve (AUC) analysis, and analyzed the impact of FTV and ctDNA on distant recurrence-free survival (DRFS) using Cox regressions. The levels of ctDNA (mean tumor molecules/mL plasma) were significantly correlated with FTV at all time points (p < 0.05). Median FTV in ctDNA-positive patients was significantly higher compared to those who were ctDNA-negative (p < 0.05). FTV and ctDNA trajectories in individual patients showed a general decrease during NAC. Exploratory analysis showed that adding ctDNA information early during treatment to FTV-based predictors resulted in numerical but not statistically significant improvements in performance for pCR prediction (e.g., AUC 0.59 vs. 0.69, p = 0.25). In contrast, ctDNA-positivity after NAC provided significant additive value to FTV in identifying patients with increased risk of metastatic recurrence and death (p = 0.004). In this pilot study, we demonstrate that ctDNA and FTV were correlated measures of tumor burden. Our preliminary findings based on a limited cohort suggest that ctDNA at surgery improves FTV as a predictor of metastatic recurrence and death. Validation in larger studies is warranted.

Fertility preservation in endocrine responsive breast cancer: data and prejudices

Even if current guidelines suggest an early referral of young breast cancer (BC) patients to fertility preservation counselling, physicians still lack knowledge about the different available strategies. Hormonal stimulation to harvest mature oocytes is considered unsafe by many oncologists and experts in reproductive medicine, particularly in the setting of oestrogen receptor-positive BC. The aim of this mini-review is to provide an overview on the available data about this topic in order to clarify potential misunderstandings and to highlight the new trends in the oncofertility field with their pros and limitations.

Impact of Pathologic Complete Response following Neoadjuvant Chemotherapy ± Trastuzumab in Locally Advanced Breast Cancer

Purpose

This study was designed to examine the relationship between breast cancer molecular subtypes and pathological response to neoadjuvant chemotherapy (NAC) ± trastuzumab, in locally advanced breast cancer (LABC).

Methods

Female patients with LABC (T2–T4, N0–N2, and M0) who received neoadjuvant chemotherapy + trastuzumab if HER2+ subtype, followed by surgery and radiotherapy ± hormonal therapy, were identified. The primary endpoint was pathologic complete response (pCR) in the breast and axilla (ypT0/ypN0), with final analysis on disease-free survival (DFS) and overall survival (OS).

Results

Six hundred eighty-one patients with a median age of 44 years, premenopausal: 70%, median tumour size: 7.0 cm (range 4–11 cm), stage II B: 27% and III A/III B: 73%, ER+/HER2−: 40.8%, ER−/HER2−: 23%, ER+/HER2+: 17.7%, and ER−/HER2+: 18.5%. Overall pCR (ypT0/ypN0) was 23%. The pCR rates based on molecular subtypes were ER+/HER2−: 9%; ER+/HER2+: 29%; ER−/HER2−: 31%; and ER−/HER2+: 37%. At median follow-up of 61 months, ER+/HER2+ and ER+/HER2− subtypes had the best 5-year DFS and OS; meanwhile, ER−/HER2+ and ER−/HER2− subtypes had the worst.

Conclusion

Women with ER+/HER2− disease are the least likely to achieve pCR, with the highest rates in HER2+ and triple-negative subgroups. Degree of response is associated with OS; despite the comparatively higher likelihood of achieving pCR in ER−/HER2+ and triple-negative, these subgroups experience a survival detriment. We are consistent with the published data that patients who attain the pathological complete response defined as ypT0/ypN0 have improved outcomes.

Trastuzumab emtansine (T-DM1) as adjuvant treatment of HER2-positive early breast cancer: safety and efficacy

Introduction: The prognosis of patients with HER2-positive early breast cancer has radically improved after the introduction of (neo)adjuvant anti-HER2 targeted therapy. Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate combining the anticancer properties of the anti-HER2 agent trastuzumab and the antineoplastic cytotoxic drug DM1. After demonstrating to be an effective and safe treatment for patients with HER2-positive advanced breast cancer, the development of T-DM1 has moved to the early setting.Areas covered: The aim of this review is to explore the current role of T-DM1 in the treatment landscape of HER2-positive early breast cancer, focusing specifically on the efficacy and safety data available in the adjuvant setting.Expert opinion: T-DM1 is an effective and safe treatment option in the adjuvant setting for patients with HER2-positive breast cancer without pathologic complete response after standard neoadjuvant chemotherapy plus anti-HER2 targeted therapy. With the availability of more effective anti-HER2 targeted agents, including T-DM1, there is an urgent need for more chemotherapy de-escalation research efforts in the early setting.

Burning Questions in the Oncofertility Counseling of Young Breast Cancer Patients

The improved prognosis of breast cancer patients makes survivorship issues an area of crucial importance. In this regard, an increased attention is needed toward the development of potential anticancer treatment-related long-term side-effects, including gonadal failure and infertility in young women. Therefore, fertility preservation and family planning are crucial issues to be addressed in all young women of reproductive age with newly diagnosed cancer. Despite a growing availability of data on the efficacy and safety of fertility preservation options and the fact that conceiving after prior history of breast cancer has become more accepted over time, there are still several gray zones in this field so that many physicians remain uncomfortable to deal with these topics. The purpose of this review is to answer some of the most controversial questions frequently asked by patients during their oncofertility counseling, in order to provide a detailed and up-to-date overview on the evidence available in this field to physicians involved in the care of young women with breast cancer.

Current State of the Art in the Adjuvant Systemic Treatment of Premenopausal Patients With Early Breast Cancer

Breast cancer is the most frequent malignancy diagnosed in premenopausal women. In this age group, breast tumors tend to be diagnosed at more advanced stages and to harbor more aggressive biological features. In addition, specific age-related issues including genetic counseling, fertility preservation, impact on social and couple relationships, working life, and management of long-term side effects should be considered highly relevant when managing early breast cancer in premenopausal women. Therefore, the care of these patients is particularly complex and a multidisciplinary approach is mandatory. The present review summarizes the current state of art in the adjuvant systemic treatment of premenopausal women with early breast cancer focusing on the optimal chemotherapy, endocrine therapy, and targeted therapy approaches in this specific patient population.

Systemic treatment of patients with early breast cancer: recent updates and state of the art

This review is focused on trials generating results that potentially impacted clinical practice since the 2017 St. Gallen Consensus; the most impactful trial was KATHERINE, which revealed a 11.3% absolute iDFS improvement with T-DM1 (compared to trastuzumab) in HER2-positive breast cancer patients who presented invasive residual disease following neoadjuvant treatment. These results, if reinforced by a subsequent overall survival benefit, will consolidate neoadjuvant treatment as the standard-of-care for most HER2-positive breast cancer patients. The addition of pertuzumab to adjuvant trastuzumab (APHINITY) or extending anti-HER2 therapy with 1 year of neratinib (ExteNET) also improved outcomes, but in a more modest way. In triple-negative early breast cancer patients presenting invasive residual disease after neoadjuvant chemotherapy, the CREATE-X trial demonstrated the benefit of post-neoadjuvant capecitabine. In patients with luminal tumours, updated results of the SOFT/TEXT trials confirmed the benefit of aromatase inhibitors plus ovarian suppression in high-risk premenopausal patients, and the 12-year results of the BIG1-98 trial demonstrated a sustained trend in favour of letrozole compared to tamoxifen in the adjuvant treatment of postmenopausal patients. The TAILOR-X study showed that, overall, patients with an intermediate recurrence risk score (11-25) in the OncotypeDX 21-gene assay did not benefit from adjuvant chemotherapy. A meta-analysis performed by the EBCTCG demonstrated that extended adjuvant aromatase inhibitors modestly reduced breast cancer recurrence risks, with a more pronounced benefit in patients previously treated with tamoxifen. Finally, an EBCTCG meta-analysis including patients with all breast cancer subtypes showed that dose-dense chemotherapy improved survival when compared to conventionally-timed chemotherapy.

Toxicity and Pharmacogenomic Biomarkers in Breast Cancer Chemotherapy

Breast cancer (BC) is one of the most prevalent types of cancer worldwide with high morbidity and mortality rates. Treatment modalities include systemic therapy, in which chemotherapy is a major component in many cases. Several chemotherapeutic agents are used in combinations or as single agents with many adverse events occurring in variable frequencies. These events can be a significant barrier in completing the treatment regimens. Germline genomic variants are thought of as potential determinants in chemotherapy response and the development of side effects. Some pharmacogenomic studies were designed to explore germline variants that can be used as biomarkers for predicting developing toxicity or adverse events during chemotherapy in BC. In this review, we reassess and summarize the major findings of pharmacogenomic studies of chemotherapy toxicity during BC management. In addition, deficiencies hampering utilizing these findings and the potential targets of future research are emphasized. Main insufficiencies in toxicity pharmacogenomics studies originate from study design, sample limitations, heterogeneity of selected genes, variants, and toxicity definitions. With the advent of high throughput genotyping techniques, researchers are expected to explore the identified as well as the potential genetic biomarkers of toxicity and efficacy to improve BC management. However, to achieve this, the limitations of previous work should be evaluated and avoided to reach more conclusive and translatable evidence for personalizing BC chemotherapy.

Neoadjuvant or adjuvant chemotherapy in early breast cancer?

INTRODUCTION

The administration of chemotherapy before (neoadjuvant), rather than after surgery (adjuvant) in early breast cancer has been considered an optional strategy for patients with operable breast cancer. We reviewed this concept considering recent results in the field.

AREAS COVERED

Herein, the authors cover neoadjuvant chemotherapy with or without biologics in triple-negative and HER2-positive operable breast cancer with a focus on rates of complete pathological remission (pCR) in the breast and axilla. The impact of the CREATE X and KATERINE randomized clinical trials of post-surgical treatments in patients with residual disease after neoadjuvant chemotherapy is also discussed.

EXPERT OPINION

The CREATE X and KATERINE clinical trials show for the first time and with methodological strengths that, in TNBC and HER2-positive breast cancer patients, post-surgical capecitabine and T-DM1, respectively, can improve prognosis when the disease persists after neoadjuvant chemotherapy. Therefore, the role of pCR as a treatment endpoint and a guide for further treatment decisions is now demonstrated. On account of these results, neoadjuvant chemotherapy becomes not an option, but rather the preferred treatment strategy for more and more TNBC and HER2-positive breast cancer patients in clinical practice.

The Molecular Mechanism of Epithelial-Mesenchymal Transition for Breast Carcinogenesis

The transforming growth factor-β (TGF-β) signaling pathway plays multiple regulatory roles in the tumorigenesis and development of cancer. TGF-β can inhibit the growth and proliferation of epithelial cells and induce apoptosis, thereby playing a role in inhibiting breast cancer. Therefore, the loss of response in epithelial cells that leads to the inhibition of cell proliferation due to TGF-β is a landmark event in tumorigenesis. As tumors progress, TGF-β can promote tumor cell invasion, metastasis, and drug resistance. At present, the above-mentioned role of TGF-β is related to the interaction of multiple signaling pathways in the cell, which can attenuate or abolish the inhibition of proliferation and apoptosis-promoting effects of TGF-β and enhance its promotion of tumor progression. This article focuses on the molecular mechanisms through which TGF-β interacts with multiple intracellular signaling pathways in tumor progression and the effects of these interactions on tumorigenesis.

Triple-negative breast cancer: current perspective on the evolving therapeutic landscape

Triple-negative breast cancer (TNBC) is known to have a poor prognosis and limited treatment options, namely chemotherapy. Different molecular studies have recently classified TNBC into different subtypes opening the door to potential new-targeted treatment options. In this review, we discuss the current standard of care in the treatment of TNBC in the neoadjuvant, adjuvant and metastatic settings. In addition, we summarize the ongoing phase III clinical trials evaluating different associations between the 3 pillars of anticancer treatment: chemotherapy, targeted therapy and immunotherapy.