Prognostic significance of residual nodal disease after neoadjuvant endocrine therapy for hormone receptor-positive breast cancer

Surgery paradigm for locally advanced breast cancer following neoadjuvant systemic therapy

Locally advanced breast cancer (LABC) remains a significant clinical challenge, particularly in developing countries. While neoadjuvant systemic therapy (NST) has improved the pathological complete response (pCR) rates, particularly in HER2-positive and triple-negative breast cancer patients, surgical management post-NST continues to evolve. The feasibility of omitting surgery and the increasing consideration of breast-conserving surgery, immediate reconstruction in LABC patients are important areas of exploration. Accurate assessment of tumor response to NST through advanced imaging and minimally invasive biopsies remains pivotal, though challenges persist in reliably predicting pCR. Additionally, axillary lymph node management continues to evolve, with emerging strategies aiming to minimize the extent of surgery in patients who achieve nodal downstaging post-NST. Minimizing axillary lymph node dissection in favor of less invasive approaches is gaining attention, though further evidence is needed to establish its oncological safety. The potential for personalized treatment approaches, reducing surgical morbidity, and improving quality of life are key goals in managing LABC, while maintaining the priority of achieving favorable long-term outcomes.

Nodal Response and Survival After Neoadjuvant Endocrine Therapy in Hormone Receptor-Positive Breast Cancer: 20-Year Experience from a Single Institution

INTRODUCTION

Axillary response to neoadjuvant endocrine therapy (NET) for the treatment of hormone receptor-positive breast cancer (HR+ BC) is not well-described. This study was designed to characterize nodal response after NET.

METHODS

Patients receiving NET followed by curative intent surgery at a comprehensive cancer center from 1998 to 2022 in a prospectively collected registry were included. Patients with distant metastasis were excluded. Primary outcome was nodal pathologic complete response (pCR). Downstaging was defined as post-NET decrease in category.

RESULTS

We included 123 patients; the majority were cT2 (n = 59) or cT3 (n = 35), and cN0 (n = 81). Median age was 70.0 years (interquartile range 62.1-76.0). Forty-two patients (34.1%) were clinically node-positive. After NET, 73 (59.8%) underwent breast-conserving surgery. All patients underwent sentinel lymph node biopsy, and 12 (9.8%) underwent completion axillary lymph node dissection. In-breast downstaging was achieved in 51 (41.5%) patients, 1 (0.8%) had breast pCR, and 14 (11.4%) had breast upstaging. Axillary downstaging was achieved in 10 (23.8%), 6 patients (14.3%) had nodal pCR, and 14 (33.3%) had axillary upstaging. At 10-year follow-up, local recurrence was 1% and distant recurrence was 14%, while disease-free survival was 82%. After adjusting for demographic and clinical factors, age was the only characteristic associated with mortality (hazard ratio 1.07, 95% confidence interval 1.01-1.13).

CONCLUSIONS

In HR+ BC treated with NET, long-term disease-free survival is good, although nodal pCR is uncommon for cN+ patients. Future studies are needed to elucidate optimal neoadjuvant systemic therapy and to delineate oncologically safe strategies to deescalate axillary management for residual microscopic disease.

Omission of Axillary Dissection in Node Positive Breast Cancer After Neoadjuvant Systemic Therapy

INTRODUCTION

Guidelines recommend axillary lymph node dissection (ALND) for ypN + positive patients as patients receiving neoadjuvant systemic therapy (NST) were excluded from trials omitting ALND in pN + patients. We sought to characterize trends in omission of ALND in patients with ypN + disease.

METHODS

Adult women with invasive breast carcinoma in the National Cancer Database between 2012 and 2019 who received NST (chemotherapy or endocrine) and had ypN + disease were included. Patients were excluded if they did not have definitive surgery within eight months of diagnosis. The primary study outcome was completion of ALND versus omission. Differences in demographics, tumor characteristics, and treatment were identified using bivariate and multivariate logistic regression models.

RESULTS

In total, 103,121 women were included. Most had cT1 (26%) or cT2 (45%) tumors, cN + disease (71%), and ductal histology (83%). 69% of patients received neoadjuvant chemotherapy and 31% neoadjuvant endocrine without chemotherapy (30% both). ALND was performed in 77% of patients. Omission of ALND became more prevalent each year from 2012 (14%) to 2019 (34%). On multivariate modeling, year of diagnosis, black race, cN status, higher grade, estrogen receptor+/HER2-receptor subtype, and mastectomy were associated with increased prevalence of ALND. Age, Charlson/Deyo comorbidity index score, endocrine versus chemotherapy, and adjuvant radiation were not associated with receipt of ALND.

CONCLUSIONS

Despite guidelines recommending ALND, omission is common in patients with ypN + breast cancer after NST. Omission of ALND increased significantly over time and is associated with clinical and demographic factors. Future study is needed to determine the oncologic safety of this approach.

Feasibility and safety of targeted axillary dissection guided by intraoperative ultrasound after neoadjuvant treatment

BACKGROUND

Axillary management in cN + axillary nodes after neoadjuvant systemic therapy (NST) in breast cancer (BC) remains under research with the aim of de-escalation of axillary node dissection (ALND). Several axillary guided localization techniques have been reported. This study evaluates the safety of intraoperative ultrasound (IOUS) guided targeted axillary dissection (TAD) in a large sample after the results of ILINA trial.

MATERIALS

Prospective data have been collected from October 2015 to June 2022 in patients with cT0-T4 and positive axillary lymph nodes (cN1) treated with NST. Before NST, an ultrasound visible marker was placed into the positive node. After NST, IOUS guided TAD was performed including sentinel node biopsy (SLN). Until December 2019, all patients underwent an ALND after TAD procedure. From January 2020, ALND was spared in those patients with an axillary pathological complete response (pCR).

RESULTS

235 patients were included. pCR (ypT0/is ypN0) was achieved in 29% patients. Identification rate (IR) of the clipped node by IOUS was 96% (95% IC, 92.5-98.1%) and IR of SLN was 95% (95% IC, 90.8-97.2%). False negative rate (FNR) for TAD procedure (SLN + clipped node) was 7.0% (95% IC, 2.3-15.7%), which decreased to 4.9% when a total of 3 or more nodes were removed. Axillary ultrasound before surgery assessed residual disease with an AUC of 0.5241. Residual axillary disease tend to be the most significant factor for axillary recurrences.

CONCLUSIONS

This study confirms the feasibility, safety and accuracy of IOUS guided surgery for axillary staging after NST in node positive BC patients.

Management of the axilla in postmenopausal patients with cN0 hormone receptor-positive/HER2-negative breast cancer treated with neoadjuvant endocrine therapy and its prognostic impact

PURPOSE

To evaluate the differences in nodal positivity if the sentinel lymph node biopsy (SLNB) is performed before or after neoadjuvant endocrine therapy (NET) in breast cancer patients, and its impact on prognosis.

METHODS

A retrospective cohort study was performed in a single center including 91 postmenopausal cases with clinically node-negative and hormone receptor-positive/HER2-negative (HR + /HER2-) breast cancer, treated with NET and SLNB. SLNB was done pre-NET until 2014, and post-NET thereafter. Axillary lymph node dissection (ALND) was indicated only in SLNB macrometastasis, although in selected elderly patients, it was omitted. Kaplan-Meier survival curves were estimated in relation to the status of the axilla, and the differences assessed using the log-rank test.

RESULTS

Between December 2006 and March 2022, SLNB was performed pre-NET in 14 cases and post-NET in 77. Both groups were similar in baseline tumor and patient characteristics. SLNB positivity was similar regardless of whether SLNB was performed before (5/14, 35.7%) or after NET (27/77, 37%), with 2/14 SLN macrometastases in the pre-NET cohort and 17/77 in the post-NET cohort. Only three patients (18.7%) with SLN macrometastasis had > 3 positive nodes following ALND. The 5-year overall survival and distant disease-free survival were 92.4% and 94.8%, respectively, with no significant differences according to SLNB status (p 0.5 and 0.8, respectively).

CONCLUSION

SLN positivity did not differ according to its timing (before or after NET). Therefore, NET has no effect on lymph node clearance. Furthermore, the prognosis is good regardless of the axillary involvement. Therefore, factors other than axillary involvement may affect the prognosis in these patients.

Contemporary approaches to the axilla in breast cancer

Over the past decade, axillary management in breast cancer has fundamentally shifted. The former notion that any degree of axillary nodal involvement warrants axillary lymph node dissection (ALND) has been challenged. Following publication of the ACOSOG Z0011 trial, national trends demonstrated significant reductions in ALND performance. Axillary radiotherapy in lieu of ALND is a consideration for select patients with a positive sentinel lymph node, while ongoing studies are investigating the role of adjuvant regional radiotherapy in women with positive nodes prior to neoadjuvant chemotherapy. Efforts toward de-escalation of axillary surgery continue to evolve, as do the indications for sentinel node biopsy omission in select subsets of patients. This review highlights the recent advances and neoteric approaches to local therapy of the axilla in breast cancer.

Surgical Management of the Axilla for Breast Cancer

This review discusses the contemporary surgical management of the axilla in patients with breast cancer. Surgical paradigms are highlighted by clinical nodal status at presentation and treatment approach, including upfront surgery and neoadjuvant systemic therapy settings. This review focuses on the increasing opportunities for de-escalating the extent of axillary surgery in the era of sentinel lymph node biopsy, while also reviewing the remaining indications for axillary clearance with axillary lymph node dissection.

Neoadjuvant endocrine therapy in postmenopausal women with HR+/HER2- breast cancer

INTRODUCTION

While endocrine therapy is the standard-of-care adjuvant treatment for hormone receptor-positive (HR+) breast cancers, there is also extensive evidence for the role of pre-operative (or neoadjuvant) endocrine therapy (NET) in HR+ postmenopausal women.

AREAS COVERED

We conducted a thorough review of the published literature, to summarize the evidence to date, including studies of how NET compares to neoadjuvant chemotherapy, which NET agents are preferable, and the optimal duration of NET. We describe the importance of on-treatment assessment of response, the different predictors available (including Ki67, PEPI score, and molecular signatures) and the research opportunities the pre-operative setting offers. We also summarize recent combination trials and discuss how the COVID-19 pandemic led to increases in NET use for safe management of cases with deferred surgery and adjuvant treatments.

EXPERT OPINION

NET represents a safe and effective tool for the management of postmenopausal women with HR+/HER2- breast cancer, enabling disease downstaging and a wider range of surgical options. Aromatase inhibitors are the preferred NET, with evidence suggesting that longer regimens might yield optimal results. However, NET remains currently underutilised in many territories and institutions. Further validation of predictors for treatment response and benefit is needed to help standardise and fully exploit the potential of NET in the clinic.

Axillary staging and management of cN + breast cancer patients treated with neoadjuvant chemotherapy: results of a survey among breast cancer surgeons in Spain

INTRODUCTION

Given the high rate of complete nodal response, the role of axillary lymph node dissection on staging the axilla has been questioned. This survey, addressed to breast cancer surgeons in Spain, has the objective of assessing current clinical trends on axillary staging of cN + patients treated with NAC.

METHODS

An online survey was conducted among breast surgeons from the Spanish Society of Surgery (AEC), Spanish Surgical Oncology Society (SEOQ), Spanish Breast Cancer Surgeons Society (AECIMA) and Spanish Gynecology and Obstetrics Society (SEGO). It was structured in 5 sections: general information and clinical practice, knowledge of clinical trials, diagnosis work-up and nodal marking, axillary staging, and axillary treatment.

RESULTS

150 breast cancer surgeons completed the full survey (96.7%). 81.8% of respondents performed SLNB or targeted axillary dissection in cN1 patients treated with NAC. Radiological axillary response was the preferred parameter guiding the surgical strategy. The excision of the clipped node (92.0%), use of dual tracer (73.2%), and axillary US (65.9%) after treatment were the most important variables considered by respondents, to increase the accuracy of SLNB in cN + patients.

CONCLUSION

This survey confirms a trend toward a less invasive approach for axillary staging in cN + patients treated with NAC among breast cancer surgeons in Spain. While there is widespread agreement in less invasive approaches to axillary staging, there is, however, a lack of consensus around treatment strategy. Further, it shows a wide heterogeneity in their clinical practice. This study highlights the need for clear evidence concerning less invasive staging procedures and their oncological safety, to ensure consistent recommendations in surgical practice.

What Is the Role of Neoadjuvant Endocrine Therapy for Breast Cancer?

There is growing interest in neoadjuvant endocrine therapy (NET) for the treatment of hormone receptor-positive, human epidermal growth factor receptor 2 -negative (HR + HER2-) breast cancer. Expanding the use of genomic assays demonstrates that many patients with HR + HER2-breast cancer do not benefit from chemotherapy, leading to growing interest in NET as a less toxic alternative. Although NET's ability to downsize breast tumors and achieve breast conservation is well-known, axillary surgery algorithms are not well-defined. Here we review primary endocrine therapy, the landmark NET clinical trials, and management of residual nodal disease following NET.

The prevalence and predictors of adjuvant chemotherapy use among patients treated with neoadjuvant endocrine therapy

PURPOSE

Neoadjuvant endocrine therapy (NET) facilitates clinical response and breast conservation in hormone receptor-positive (HR-positive) breast cancer. Patient selection for adjuvant chemotherapy (CT) post-NET is unclear and potentially evolving with use of genomic assays. We evaluated post-NET CT use in a national dataset.

METHODS

Using the National Cancer DataBase, we identified patients with cT2-3N0-3M0 HR-positive/human epidermal growth factor receptor 2-negative breast cancer treated between 2010 and 2017 with 3-12 months of NET prior to breast surgery. CT use was evaluated in the overall population, in patients with a pathologic complete response (pCR) and in patients with ypT1-2N0 disease (approximating PEPI 0). Exploratory analysis included patients > 50 years with ypN0-1, and 21-gene recurrence score (RS) ≤ 25 (approximating TAILORx/RxPONDER populations not benefiting from CT). Multivariable logistic regression was used to identify factors associated with CT.

RESULTS

Among 3624 eligible patients, 20.4% (740/3624) received CT. On multivariable analysis, age ≤ 50, lobular histology, grade 2, progesterone receptor negativity, ypT3, ypN + and RS ≥ 18 were associated with CT receipt. Co-morbidity, longer NET duration, ypT4, ypNx, and RS < 18 were associated with CT omission. CT was administered to 3.3% (1/30) of patients experiencing pCR and 5.5% (82/1483) with ypT1-2N0 disease. Among patients > 50 years with ypT0-3N0-1 residual disease, 13.8% (355/2569) received CT; RS was available for 24.8% (88/355) and 60% (53/88) had a score 0-25.

CONCLUSION

A minority of patients receive CT post-NET. This decision appears to be driven by younger age, RS and pathological nodal status. Increased consideration of these factors prior to neoadjuvant treatment choice may be warranted.

Assessment of preoperative axillary nodal disease burden: breast MRI in locally advanced breast cancer before, during and after neoadjuvant endocrine therapy

Background

Axillary lymph node (LN) metastasis is one of the most important predictors of recurrence and survival in breast cancer, and accurate assessment of LN involvement is crucial. Determining extent of residual disease is key for surgical planning after neoadjuvant therapy. The aim of the study was to evaluate the diagnostic reliability of MRI for nodal disease in locally advanced breast cancer patients treated with neoadjuvant endocrine therapy (NET).

Methods

Thirty-three clinically node-positive locally advanced breast cancer patients who underwent NET and surgery were prospectively enrolled. Two radiologists reviewed the axillary nodes at 3 separate time points MRI examinations at baseline (before the first treatment regimen), interim (following at least 2 months after the first cycle and prior to crossing-over), and preoperative (after the final administration of therapy and immediately before surgery). According to LN status after surgery, imaging features and diagnostic performance were analyzed.

Results

All 33 patients had a target LN reduction, the greatest treatment benefit from week 8 to week 16.

There was a positive correlation between the maximal diameter of the most suspicious LN measured by MRI and pathology during and after NET, being highest at therapy completion (r = 0.6, P ≤ .001). Mean and median differences of maximal diameter of the most suspicious LN were higher with MRI than with pathology. Seven of 33 patients demonstrated normal posttreatment MRI nodal status (yrN0). Of these 7 yrN0, 3 exhibited no metastasis on final pathology (ypN0), 2 ypN1 and 2 ypN2. Reciprocally, MRI diagnosed 3 cases of ypN0 as yrN + . Diffusion -weighted imaging (DWI) was the only axillary node characteristic significant when associated with pathological node status (χ²(4) = 8.118, P = .072).

Conclusion

Performance characteristics of MRI were not completely sufficient to preclude surgical axillary staging. To our knowledge, this is the first study on MRI LN assessment following NET in locally advanced breast cancer, and further studies with larger sample sizes are required to consolidate the results of this preliminary study.

Trial Registration

Institutional Review Board approval was obtained (this current manuscript is from a prospective, open-label, randomized single-center cohort substudy of the NEOLETEXE trial). NEOLETEXE, a phase 2 clinical trial, was registered on March 23^rd, 2015 in the National trial database of Norway and approved by the Regional Ethical Committee of the South-Eastern Health Region in Norway; registration number: REK-SØ-84–2015.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09813-9.

The Clinical Impact of Neoadjuvant Endocrine Treatment on Luminal-like Breast Cancers and Its Prognostic Significance: Results from a Single-Institution Prospective Cohort Study

Purpose: Neoadjuvant endocrine treatment (NET) has become a useful tool for the downstaging of luminal-like breast cancers in postmenopausal patients. It enables us to increase breast- conserving surgery (BCS) rates, provides an opportunity for us to assess in vivo NET effectiveness, and allows us to study any biological changes that may act as valid biomarkers. The purpose of this study was to evaluate the safety and effectiveness of NET, and to assess the role of Ki67 proliferation rate changes as an indicator of endocrine responsiveness. Methods: From 2016 to 2020, a single-institution cohort of patients, treated with NET and further surgery, was evaluated. In patients with Ki67 ≥ 10%, a second core biopsy was performed after four weeks. Information regarding histopathological and clinical changes was gathered. Results: A total of 115 estrogen receptor-positive (ER+)/HER2-negative patients were included. The median treatment duration was 5.0 months (IQR: 2.0−6.0). The median maximum size in the surgical sample was 40% smaller than the pretreatment size measured by ultrasound (p < 0.0001). The median pretreatment Ki67 expression was 20.0% (IQR: 12.0−30.0), and was reduced to 5.0% (IQR: 1.8−10.0) after four weeks, and to 2.0% (IQR: 1.0−8.0) in the surgical sample (p < 0.0001). BCS was performed on 98 patients (85.2%). No pathological complete responses were recorded. A larger Ki67 fold change after four weeks was significantly related to a PEPI score of zero (p < 0.002). No differences were observed between luminal A- and B-like tumors, with regard to fold change and PEPI score. Conclusions: In our cohort, NET was proven to be effective for tumor size and Ki67 downstaging. This resulted in a higher rate of conservative surgery, aided in therapeutic decision making, provided prognostic information, and constituted a safe and well-tolerated approach.

Axillary Lymph Node Dissection Rates and Prognosis From Phase III Neoadjuvant Systemic Trial Comparing Neoadjuvant Chemotherapy With Neoadjuvant Endocrine Therapy in Pre-Menopausal Patients With Estrogen Receptor-Positive and HER2-Negative, Lymph Node-Positive Breast Cancer

In this study, we aimed to evaluate axillary lymph node dissection (ALND) rates and prognosis in neoadjuvant chemotherapy (NCT) compare with neoadjuvant endocrine therapy (NET) in estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-), lymph node (LN)-positive, premenopausal breast cancer patients (NCT01622361). The multicenter, phase 3, randomized clinical trial enrolled 187 women from July 5, 2012, to May 30, 2017. The patients were randomly assigned (1:1) to either 24 weeks of NCT including adriamycin plus cyclophosphamide followed by intravenous docetaxel, or NET involving goserelin acetate and daily tamoxifen. ALND was performed based on the surgeon’s decision. The primary endpoint was ALND rate and surgical outcome after preoperative treatment. The secondary endpoint was long-term survival. Among the 187 randomized patients, pre- and post- neoadjuvant systemic therapy (NST) assessments were available for 170 patients. After NST, 49.4% of NCT patients and 55.4% of NET patients underwent mastectomy after treatment completion. The rate of ALND was significantly lower in the NCT group than in the NET group (55.2% vs. 69.9%, P=.046). Following surgery, the NET group showed a significantly higher mean number of removed LNs (14.96 vs. 11.74, P=.003) and positive LNs (4.84 vs. 2.92, P=.000) than the NCT group. The axillary pathologic complete response (pCR) rate was significantly higher in the NCT group (13.8% vs. 4.8%, P=.045) than in the NET group. During a median follow-up of 67.3 months, 19 patients in the NCT group and 12 patients in the NET group reported recurrence. The 5-year ARFS (97.5%vs. 100%, P=.077), DFS (77.2% vs. 84.8%, P=.166), and OS (97.5% vs. 94.7%, P=.304) rates did not differ significantly between the groups. In conclusion, although survival did not differ significantly, more NCT patients might able to avoid ALND, with fewer LNs removed with lower LN positivity.

De-escalation of axillary irradiation for early breast cancer - Has the time come?

Introduction of sentinel lymph node biopsy, initially in clinically node-negative and subsequently in patients presenting with involved axilla and downstaged by primary systemic therapy, allowed for significant decrease in morbidity compared to axillary lymph node dissection. Concurrently, regional nodal irradiation was demonstrated to improve outcomes in most node-positive patients. Additionally, over the last decades, introduction of more effective systemic therapies has resulted in improvements not only at distant sites, but also in locoregional control, creating space for de-escalation of locoregional treatments. We discuss the data on de-escalation in axillary surgery and irradiation, both in patients undergoing upfront surgery and primary systemic therapy, with special emphasis on the feasibility of omission of nodal irradiation in patients undergoing primary systemic therapy. In view of the accumulating evidence, omission of axillary irradiation may be considered in clinically node-positive patients converting after primary systemic therapy to pathologically negative nodes on sentinel lymph node biopsy (preferably also with in-breast pCR), presenting with lower initial nodal stage, older age and were treated with breast-conserving surgery followed by whole breast irradiation. Omission of regional nodal irradiation in patients with aggressive tumor phenotypes achieving a pCR is under investigation. In patients undergoing preoperative endocrine therapy the adoption of axillary management strategies utilized in case of upfront surgery seems more suitable than those used in post chemotherapy-based primary systemic therapy setting.

Surgical Management of Axilla Following Neoadjuvant Endocrine Therapy

BACKGROUND

Randomized clinical trials support deescalation of axillary surgery in breast cancer patients with low-volume axillary disease treated with a surgery-first approach. However, few data exist to guide axillary surgery following neoadjuvant endocrine therapy (NET). Therefore, we evaluated the extent and outcomes of axillary surgery in a contemporary cohort of NET patients, a treatment approach that has become particularly relevant during the coronavirus disease-19 (COVID-19) pandemic.

PATIENTS AND METHODS

We identified invasive breast cancer patients treated with NET between October 2008 and November 2019. Patients presenting with stage IV disease or recurrent disease were excluded. Statistical analyses were performed using chi-square, Fisher's exact, and Wilcoxon rank-sum tests.

RESULTS

194 invasive breast cancers in 186 patients (median age 66 years) were evaluated; 81 patients had breast-conserving surgery (BCS), while 113 underwent mastectomy. Eighty-four patients (43.3%) were biopsy-proven cN+ with 4/84 (4.8%) ypN0 following NET. Among cN+ patients, 14 (16.7%) had sentinel lymph node biopsy (SLNB) only, 27 (32.1%) had SLNB + axillary lymph node dissection (ALND), and 43 (51.2%) had ALND. Among 110 cN0 patients, 99 had axillary surgery with 28/99 (28.3%) ypN+: SLNB in 83 (75.5%), SLNB+ALND in 14 (12.7%), and ALND in 2 (1.8%). Among all ypN+ patients, 23/108 (21.3%) had SLNB alone: 18/43 (41.9%) of BCS and 5/65 (7.7%) mastectomy patients (p < 0.001). After median follow-up of 35 months, no regional recurrences were observed.

CONCLUSIONS

Among biopsy-proven cN+ NET patients, we observed deescalation of axillary surgery in selected patients, despite a low nodal pathologic complete response (pCR) rate, without nodal recurrences. These data suggest that patients with low-volume axillary disease treated with NET may be managed similarly to patients treated with a surgery-first approach.

Optimal Management for Residual Disease Following Neoadjuvant Systemic Therapy

OPINION STATEMENT

Treatment sequencing in early-stage breast cancer has significantly evolved in recent years, particularly in the triple negative (TNBC) and human epidermal growth factor receptor 2 (HER2)-positive subsets. Instead of surgery first followed by chemotherapy, several clinical trials showed benefits to administering systemic chemotherapy (and HER2-targeted therapies) prior to surgery. These benefits include more accurate prognostic estimates based on the extent of residual cancer that can also guide adjuvant treatment, and frequent tumor downstaging that can lead to smaller surgeries in patients with large tumors at diagnosis. Patients with extensive invasive residual cancer after neoadjuvant therapy are at high risk for disease recurrence, and two pivotal clinical trials, CREATE-X and KATHERINE, demonstrated improved recurrence free survival with adjuvant capecitabine and ado-trastuzumab-emtansine (T-DM1) in TNBC and HER2-positive residual cancers, respectively. Patients who achieve pathologic complete response (pCR) have excellent long-term disease-free survival regardless of what chemotherapy regimen induced this favorable response. This allows escalation or de-escalation of adjuvant therapy: patients who achieved pCR could be spared further chemotherapy, while those with residual cancer could receive additional chemotherapy postoperatively. Ongoing clinical trials are testing this strategy (CompassHER2-pCR: NCT04266249). pCR also provides an opportunity to assess de-escalation of locoregional therapies. Currently, for patients with residual disease in the lymph nodes (ypN+), radiation therapy entails coverage of the undissected axilla, and may include supra/infraclavicular/internal mammary nodes in addition to the whole breast or chest wall, depending on the type of surgery. Ongoing trials are testing the safety of omitting post-mastectomy breast and post-lumpectomy nodal irradiation (NCT01872975) as well as omitting axillary lymph node dissection (NCT01901094) in the setting of pCR. Additionally, evolving technologies such as minimal residual disease (MRD) monitoring in the blood during follow-up may allow early intervention with "second-line systemic adjuvant therapy" for patients with molecular relapse which might prevent impending clinical relapse.

The Present and Future of Neoadjuvant Endocrine Therapy for Breast Cancer Treatment

Simple Summary

The treatment of breast cancer has evolved considerably over the last two decades, leading toward individualized disease management. Hormone-sensitive breast cancers constitute the vast majority of cases and endocrine therapy is the mainstay of their treatment. On the other hand, neoadjuvant or pre-surgical treatments provide a number of advantages for tumor management. In this review we will discuss the existing evidence on neoadjuvant endocrine therapy, as well as its possible future indications.

Abstract

Endocrine therapy (ET) has established itself as an efficacious treatment for estrogen receptor-positive (ER+) breast cancers, with a reduction in recurrence rates and increased survival rates. The pre-surgical approach with chemotherapy (NCT) has become a common form of management for large, locally advanced, or high-risk tumors. However, a good response to NCT is not usually expected in ER+ tumors. Good results with primary ET, mainly in elderly women, have encouraged studies in other stages of life, and nowadays neoadjuvant endocrine treatment (NET) has become a useful approach to many ER+ breast cancers. The aim of this review is to provide an update on the current state of art regarding the present and the future role of NET.

Neoadjuvant endocrine therapy use in early stage breast cancer during the covid-19 pandemic

Purpose

Physician treatment preferences for early stage, estrogen positive breast cancer (ER + BC) patients were evaluated during the initial surge of the COVID-19 pandemic in the US when neoadjuvant endocrine therapy (NET) was recommended to allow safe deferral of surgery.

Methods

A validated electronic survey was administered May–June, 2020 to US medical oncologists (MO), radiation oncologists (RO), and surgeons (SO) involved in clinical trials organizations. Questions on NET use included practice patterns for locoregional management following NET.

Results

114 Physicians from 29 states completed the survey—42 (37%) MO, 14 (12%) RO, and 58 (51%) SO. Before COVID-19, most used NET ‘rarely’ (49/107, 46%) or ‘sometimes’ (36, 33%) for ER + BC. 46% would delay surgery 2 months without NET. The preferred NET regimen was tamoxifen for premenopausal and aromatase inhibitor for postmenopausal women. 53% planned short term NET until surgery could proceed. Most recommended omitting axillary lymph node dissection (ALND) for one micrometastatic node after 1, 2, or 3 months of NET (1 month, N = 56/93, 60%; 2 months, N = 54/92, 59%; 3 months, N = 48/90, 53%). With longer duration of NET, omission of ALND decreased, regardless of years in practice, percent of practice in BC, practice type, participation in multidisciplinary tumor board, or number of regional COVID-19 cases.

Conclusion

More physicians preferred NET for ER + BC during the pandemic, compared with pre-pandemic times. As the duration of NET extended, more providers favored ALND in low volume metastatic axillary disease. The Covid-19 pandemic affected practice of ER + BC; it remains to be seen how this may impact outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06153-3.

Biological effects of NODAL on endometrial cancer cells and its underlying mechanisms

Activin A receptor type 1C (ALK7) and its ligand nodal growth differentiation factor (NODAL) serve numerous roles in cancer cells, including regulating cancer invasion, migration and apoptosis. NODAL promotes breast cancer cell apoptosis by activating ALK7; however, ALK7 and NODAL expression in endometrial cancer (EC), as well as their effects and underlying mechanisms in EC cells, are not completely understood. The present study aimed to characterize the expression of NODAL and ALK7 in EC, as well as the underlying mechanisms. The expression levels of ALK7 and NODAL were detected via reverse transcription-quantitative PCR and western blotting. Cell transfection was performed to overexpress NODAL or interfere ALK7. Cell proliferation, invasion and migration were detected via Cell Counting Kit-8, Transwell and wound healing assays, respectively. Flow cytometry was performed to detect cell apoptosis and western blotting was conducted to detect the expression levels of apoptosis-related proteins. NODAL and ALK7 expression levels were significantly decreased in EC cell lines compared with normal endometrial cells. NODAL overexpression inhibited EC cell proliferation, invasion and migration, and promoted EC cell apoptosis compared with the overexpression-negative control (Ov-NC) group. Moreover, NODAL overexpression significantly increased ALK7 expression levels in EC cells compared with the Ov-NC group. ALK7 reversed NODAL overexpression-mediated inhibition of EC cell proliferation, invasion and migration, and promotion of EC cell apoptosis. The present study indicated that NODAL inhibited EC cell proliferation, invasion and migration, and promoted EC cell apoptosis by activating ALK7.

Neoadjuvant Endocrine Therapy in Breast Cancer Management: State of the Art

Endocrine therapy is the mainstay of treatment in HR+/HER2- breast cancers, which represent about 70% of all breast cancers. Neoadjuvant therapy has been developed since the 1990s to address several issues, including breast-conserving surgery (BCS) and improvement of survival rates. For a long time, neoadjuvant endocrine therapy (NET) was confined to frail patients in order to improve surgery outcome. Since the 2000s, NET now plays a central role as a research tool for predictive endocrine sensitivity biomarkers and targeted therapies. One of the major issues in early HR+/HER2- breast cancer is to identify patients in whom chemotherapy can be safely withheld. In vivo assessment of response to NET might be the best treatment strategy to address this issue.

Axillary Management After Neoadjuvant Endocrine Therapy for Hormone Receptor-Positive Breast Cancer

BACKGROUND

Data to guide axillary management after neoadjuvant endocrine therapy (NET) remain limited.

METHODS

We analyzed type of axillary surgery [sentinel lymph node biopsy (SLNB) vs. axillary lymph node dissection (ALND)] and residual nodal disease burden after NET in two cohorts of patients with cT1-4N0-1M0 hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer: Dana-Farber/Brigham and Women's Cancer Center (DFBWCC) cohort (2015-2018) and the National Cancer Data Base (NCDB) cohort (2012-2016). Cox proportional hazard regression was used to determine adjusted 5-year overall survival (OS) by type of axillary surgery.

RESULTS

Ninety-four (4.3%) of 2191 HR+/HER2- DFBWCC patients and 4363 (1.5%) of 283,344 NCDB patients were selected for NET. Of those who underwent axillary surgery, 30 (43.5%) in the DFBWCC cohort and 1583 (40.6%) in the NCDB cohort had ALND. Over 90% of cN0 patients in both cohorts had fewer than three positive nodes on final pathology [44 (95.7%) DFBWCC and 2945 (91.3%) NCDB]. In contrast, only 7 (30.4%) DFBWCC patients and 342 (50.7%) NCDB cN1 patients had fewer than three positive nodes. In the DFBWCC patients, there were no locoregional recurrences and four distant recurrences. In the NCDB, 5-year OS did not differ by type of axillary surgery regardless of residual nodal disease burden: 96.6% SLNB versus 97.9% ALND for 0 positive nodes; 84.4% versus 84.4% for one to two positive nodes, and 75.9% versus 77.3% for three or more positive nodes (all p > 0.10).

CONCLUSIONS

In cN0 patients selected for NET, > 90% have fewer than three positive nodes at surgery. The lack of a survival difference between SLNB and ALND suggests an opportunity to de-escalate treatment of the axilla in patients with limited residual nodal disease.