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

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.

Prediction of the number of positive axillary lymph nodes according to sentinel lymph node involvement and biological subtypes in patients receiving neoadjuvant chemotherapy

BACKGROUND

Sentinel lymph node biopsy (SLNB) has replaced axillary lymph node dissection (ALND) for assessing axillary lymph node status in clinically node-negative breast cancer patients. However, the approach to axillary surgery after neoadjuvant treatment is still controversial. In the present study, our objective was to predict the pathological nodal stage based on SLNB results and the clinicopathological characteristics of patients who initially presented with clinical N1 positivity but whose disease status was converted to clinical N0 after neoadjuvant chemotherapy (NAC).

MATERIALS AND METHODS

After NAC, 150 clinically node-negative patients were included. The relationships between clinicopathologic parameters and the number of positive lymph nodes in SLNBs and ALNDs were assessed through binary/multivariate logistic regression analysis.

RESULTS

Among 150 patients, 78 patients had negative SLNBs, and 72 patients had positive SLNBs. According to the ALND data of 21 patients with SLNB1+, there was no additional node involvement (80.8%), 1-2 lymph nodes were positive in 5 patients (19.2%), and no patient had ≥ 3 lymph nodes involved. Following the detection of SLNB1 + positivity, the rate of negative non-sentinel nodes were 75% in the luminal A/B subgroup, 100% in the HER-2-positive subgroup, and 100% in the triple-negative subgroup. Patients with a lower T stage (T1-3 vs. T4), fewer than 4 clinical nodes before NAC (< 4 vs. ≥4), and a decreased postoperative Ki-67 index (< 10% vs. stable/increase) were included. According to both univariate and multivariate analyses, being in the triple-negative or HER2-positive subgroup, compared to the luminal A/B subgroup (luminal A/B vs. HER2-positive/triple-negative), was found to be predictive of complete lymph node response.

CONCLUSION

The number of SLNB-positive nodes, tumor-related parameters, and response to treatment may predict no additional nodes to be positive at ALND.

Favorable outcome of neoadjuvant endocrine treatment than surgery-first in female HR-positive/HER2-negative breast cancer patients-A NCDB analysis (2010-2016)

PURPOSE

To assess the efficacy of neoadjuvant endocrine therapy in female HR-positive/HER2-negative breast cancer patients.

DATA AND METHODS

We identified female patients aged ≥18 years with cT1-4N0-XM0, HR(+), and HER2(-) breast cancer from the National Cancer Database. The patients who underwent surgery first were categorized as "surgery-first," while those who received NET before surgery were classified as "NET." Propensity score-matching, Cox proportional-hazard model, variance inflation factors, and interaction analysis were employed to estimate the correlation between NET and survival outcomes.

RESULTS

Among 432,387 cases, 2914 NET patients and 2914 surgery-first patients were matched. Compared with the surgery-first group, the NET group received less adjuvant chemotherapy (p < 0.001). Furthermore, the NET group exhibited higher survival probabilities compared with the surgery-first group (3 years: 91.4% vs. 82.1%; 5 years: 82.1% vs. 66.8%). Multivariate Cox analysis indicated that NET was associated with improved OS (surgery-first vs. NET: HR 2.17, 95% CI: 1.93-2.44). Age over 55 years old, having public insurance, higher CDCC score, higher NSBR grade, ER(+)PR(-), and advanced clinical stage were related to worse OS (all p < 0.05). There was an interaction between age, race, income, and home and treatment regimen (all p < 0.05).

CONCLUSION

NET may be a more effective treatment procedure than surgery-first in female HR-positive/HER2-negative, non-metastatic breast cancer patients. Future clinical studies with more detailed data will provide higher-level evidence-based data.

Endocrine-Sensitive Disease Rate in Postmenopausal Patients With Estrogen Receptor-Rich/ERBB2-Negative Breast Cancer Receiving Neoadjuvant Anastrozole, Fulvestrant, or Their Combination: A Phase 3 Randomized Clinical Trial

Importance

Adding fulvestrant to anastrozole (A+F) improved survival in postmenopausal women with advanced estrogen receptor (ER)-positive/ERBB2 (formerly HER2)-negative breast cancer. However, the combination has not been tested in early-stage disease.

Objective

To determine whether neoadjuvant fulvestrant or A+F increases the rate of pathologic complete response or ypT1-2N0/N1mic/Ki67 2.7% or less residual disease (referred to as endocrine-sensitive disease) over anastrozole alone.

Design, Setting, and Participants

A phase 3 randomized clinical trial assessing differences in clinical and correlative outcomes between each of the fulvestrant-containing arms and the anastrozole arm. Postmenopausal women with clinical stage II to III, ER-rich (Allred score 6-8 or >66%)/ERBB2-negative breast cancer were included. All analyses were based on data frozen on March 2, 2023.

Interventions

Patients received anastrozole, fulvestrant, or a combination for 6 months preoperatively. Tumor Ki67 was assessed at week 4 and optionally at week 12, and if greater than 10% at either time point, the patient switched to neoadjuvant chemotherapy or immediate surgery.

Main Outcomes and Measures

The primary outcome was the endocrine-sensitive disease rate (ESDR). A secondary outcome was the percentage change in Ki67 after 4 weeks of neoadjuvant endocrine therapy (NET) (week 4 Ki67 suppression).

Results

Between February 2014 and November 2018, 1362 female patients (mean [SD] age, 65.0 [8.2] years) were enrolled. Among the 1298 evaluable patients, ESDRs were 18.7% (95% CI, 15.1%-22.7%), 22.8% (95% CI, 18.9%-27.1%), and 20.5% (95% CI, 16.8%-24.6%) with anastrozole, fulvestrant, and A+F, respectively. Compared to anastrozole, neither fulvestrant-containing regimen significantly improved ESDR or week 4 Ki67 suppression. The rate of week 4 or week 12 Ki67 greater than 10% was 25.1%, 24.2%, and 15.7% with anastrozole, fulvestrant, and A+F, respectively. Pathologic complete response/residual cancer burden class I occurred in 8 of 167 patients and 17 of 167 patients, respectively (15.0%; 95% CI, 9.9%-21.3%), after switching to neoadjuvant chemotherapy due to week 4 or week 12 Ki67 greater than 10%. PAM50 subtyping derived from RNA sequencing of baseline biopsies available for 753 patients (58%) identified 394 luminal A, 304 luminal B, and 55 nonluminal tumors. A+F led to a greater week 4 Ki67 suppression than anastrozole alone in luminal B tumors (median [IQR], -90.4% [-95.2 to -81.9%] vs -76.7% [-89.0 to -55.6%]; P < .001), but not luminal A tumors. Thirty-six nonluminal tumors (65.5%) had a week 4 or week 12 Ki67 greater than 10%.

Conclusions and Relevance

In this randomized clinical trial, neither fulvestrant nor A+F significantly improved the 6-month ESDR over anastrozole in ER-rich/ERBB2-negative breast cancer. Aromatase inhibition remains the standard-of-care NET. Differential NET response by PAM50 subtype in exploratory analyses warrants further investigation.

Trial Registration

ClinicalTrials.gov Identifier: NCT01953588.

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.

Frequent upregulation of HER2 protein in hormone-receptor-positive HER2-negative breast cancer after short-term neoadjuvant endocrine therapy

BACKGROUND

Endocrine resistant metastatic disease develops in ~ 20-25% of hormone-receptor-positive (HR+) breast cancer (BC) patients despite endocrine therapy (ET) use. Upregulation of HER family receptor tyrosine kinases (RTKs) represent escape mechanisms in response to ET in some HR+ tumors. Short-term neoadjuvant ET (NET) offers the opportunity to identify early endocrine escape mechanisms initiated in individual tumors.

METHODS

This was a single arm, interventional phase II clinical trial evaluating 4 weeks (± 1 week) of NET in patients with early-stage HR+/HER2-negative (HER2-) BC. The primary objective was to assess NET-induced changes in HER1-4 proteins by immunohistochemistry (IHC) score. Protein upregulation was defined as an increase of ≥ 1 in IHC score following NET.

RESULTS

Thirty-seven patients with cT1-T3, cN0, HR+/HER2- BC were enrolled. In 35 patients with evaluable tumor HER protein after NET, HER2 was upregulated in 48.6% (17/35; p = 0.025), with HER2-positive status (IHC 3+ or FISH-amplified) detected in three patients at surgery, who were recommended adjuvant trastuzumab-based therapy. Downregulation of HER3 and/or HER4 protein was detected in 54.2% of tumors, whereas HER1 protein remained low and unchanged in all cases. While no significant volumetric reduction was detected radiographically after short-term NET, significant reduction in tumor proliferation rates were observed. No significant associations were identified between any clinicopathologic covariates and changes in HER1-4 protein expression on multivariable analysis.

CONCLUSION

Short-term NET frequently and preferentially upregulates HER2 over other HER family RTKs in early-stage HR+/HER2- BC and may be a promising strategy to identify tumors that utilize HER2 as an early endocrine escape pathway.

CLINICAL TRIAL REGISTRY

Trial registration number: NCT03219476.

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.

Frequent Upregulation Of HER2 Protein In Hormone Receptor-Positive HER2-Negative Breast Cancer After Short-Term Neoadjuvant Endocrine Therapy

Background. Endocrine resistant metastatic disease develops in ~20-25% of hormone-receptor positive (HR+) breast cancer (BC) patients despite endocrine therapy (ET) use. Upregulation of HER family receptor tyrosine kinases (RTKs) represent escape mechanisms in response to ET in some HR+ tumors. Short-term neoadjuvant ET (NET) offers the opportunity to identify early endocrine escape mechanisms initiated in individual tumors. Methods. This was a single arm, interventional phase II clinical trial evaluating 4 weeks (+/-1 week) of NET in patients with early-stage HR+/HER2-negative (HER2-) BC. The primary objective was to assess NET-induced changes in HER1-4 proteins by immunohistochemistry (IHC) score. Protein upregulation was defined as an increase of ≥1 in IHC score following NET. Results. Thirty-seven patients with cT1-T3, cN0, HR+/HER2- BC were enrolled. In 35 patients with evaluable tumor HER protein after NET, HER2 was upregulated in 48.6% (17/35; p=0.025), with HER2-positive status (IHC 3+ or FISH-amplified) detected in three patients at surgery, who were recommended adjuvant trastuzumab-based therapy. Downregulation of HER3 and/or HER4 protein was detected in 54.2% of tumors, whereas HER1 protein remained low and unchanged in all cases. While no significant volumetric reduction was detected radiographically after short-term NET, significant reduction in tumor proliferation rates were observed. No significant associations were identified between any clinicopathologic covariates and changes in HER1-4 protein expression on multivariable analysis. Conclusion . Short-term NET frequently and preferentially upregulates HER2 over other HER-family RTKs in early-stage HR+/HER2- BC and may be a promising strategy to identify tumors that utilize HER2 as an early endocrine escape pathway. Trial registration number: NCT03219476 Date of registration for prospectively registered trials: July 17, 2017.

Localizing Positive Axillary Lymph Nodes in Breast Cancer Patients Post Neoadjuvant Therapy

INTRODUCTION

Multiple trials demonstrated the feasibility of sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy. Those trials reported > 10% false-negative rate; however, a subset analysis of the Z1071 trial demonstrated that removing the clipped positive lymph node (LN) during SLNB reduces the false-negative rate to 6.8% post neoadjuvant chemotherapy. This study examines the factors that might contribute to the ability to identify the clipped nodes post neoadjuvant therapy (NAT).

MATERIALS AND METHODS

Breast cancer patients with biopsy-proven metastatic axillary LN who underwent NAT, converted to N0, had preoperative localization, and then SLNB between 2018 and 2020 at a single institution were identified. A retrospective chart review was performed. Demographic and preoperative variables were compared between localization and nonlocalization groups.

RESULTS

Eighty patients who met inclusion criteria were included. A total of 39 patients were localized after NAT completion (49%). Only half of the patients with ultrasound-detectable marker clips were able to be localized. Minimal LN abnormality was seen in imaging after NAT completion in 39 patients and is significantly associated with localization; 26 (67%) were localized (Odds Ratio 4.31, P = 0.002, 95% Confidence Interval 1.69-10.98).

CONCLUSIONS

Our study suggests that radiologically abnormal LNs on preoperative imaging after NAT completion are more likely to be localized. Nodes that ultimately normalize by imaging criteria remain a significant challenge to localize, and thus localization before starting NAT is suggested. A better technology is needed for LN localization after prolonged NAT for best accuracy and avoids repeated procedures.

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.

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.

Impact of COVID-19 Disease in Early Breast Cancer Management: A Summary of the Current Evidence

An expert panel on breast cancer and COVID-19 disease was convened to address the impact of the COVID-19 pandemic for early breast cancer (eBC) management.

Locoregional Management of Early-Stage Breast Cancer

The latest version of NCCN Guidelines for Breast Cancer on locoregional management of early-stage breast cancer contains numerous updated recommendations, particularly focusing on management of the axilla, locoregional management after neoadjuvant therapy, and radiation delivery. Recommendations for axillary staging have been separated for patients who have undergone breast-conserving surgery and those who have had a mastectomy, creating 2 individual pathways. The section on locoregional treatment after neoadjuvant therapy has been reformatted; optimal management of this patient group continues to evolve. Lastly, specifics regarding the delivery and sequencing of radiotherapy have been updated.

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 Response to Neoadjuvant Therapy in Node-Positive, Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer Patients: Predictors and Oncologic Outcomes

BACKGROUND

One potential benefit of neoadjuvant therapy (NAT) in node-positive, estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) patients is axillary downstaging to avoid axillary dissection.

OBJECTIVE

The aim of this study was to evaluate axillary response to NAT with chemotherapy (NCT) or endocrine therapy (NET) and identify potential predictors of response.

METHODS

A prospectively collected database was queried for node-positive, ER+, HER2- breast cancer patients treated with NAT and surgery from January 2011 to September 2020. Axillary response was categorized into pathologic complete response (pCR) versus no pCR, and was correlated to demographic and clinicopathologic parameters in a logistic regression model.

RESULTS

A cohort of 176 eligible patients was identified and 178 breast cancers were included in the study. The overall axillary pCR rate was 12.3% (22/178). NCT and NET achieved response rates of 13.9% (19/137) and 7.3% (3/41), respectively (p = 0.232). A significantly higher axillary pCR rate was identified in patients with clinical stage II at diagnosis (12/60, 20%) compared with stage III (10/118, 8.4%; p = 0.03). NET patients with ypN0 were younger and were treated for a longer period of time (>6 months). Completion axillary dissection was omitted in the majority (73.7%) of NCT patients achieving axillary pCR.

CONCLUSIONS

For patients with node-positive, ER+, HER2- breast cancer, a lower burden of disease at the time of diagnosis (stage II) is associated with a significantly higher axillary pCR, enabling those patients to be spared axillary dissection. Further studies are necessary to define the role of genomic profiling in predicting axillary response.

Neoadjuvant Endocrine Therapy in Clinical Practice: A Review

Importance

In clinical practice, neoadjuvant endocrine therapy (NET) is rarely used despite being an effective treatment modality able to downstage tumors and facilitate breast-conserving surgery.

Observations

Using data from studies conducted since 2000, we provide readers with a critical in-depth review on clinical aspects related to the application of NET in the treatment of hormone receptor (HR)-positive/ERBB2 (formerly HER2)-negative breast cancer. This includes an overview of patient-selection criteria, regimen choice, treatment duration, evaluation of response by imaging, interpretation of pathology after treatment, and surgical considerations. Areas of controversy include the use of gene-expression tests for patient selection, treatment of premenopausal women, surgical management of the axilla after NET, and adjuvant systemic therapy decision-making, including the use of chemotherapy.

Conclusions and Relevance

NET is an optimal treatment modality for a considerable proportion of postmenopausal women diagnosed with HR-positive tumors. The treatment landscape for HR-positive breast cancer is evolving, with novel agents and the growing use of gene expression profiling to define treatment selection. As such, it is likely that NET use will increase and the practical considerations outlined here will become more important.

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.

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.