Increase in response rate by prolonged treatment with neoadjuvant letrozole

Efficacy of Presurgical Short-Term Endocrine Therapy During the Waiting Period for Surgery in Postmenopausal Hormone Receptor-Positive Breast Cancer

Background: Although presurgical endocrine therapy has been used to enhance the rate of breast cancer conservation, its prognostic relevance is unknown. The search for a valid prognostic factor equivalent to pathological complete response in presurgical chemotherapy remains a challenge in presurgical endocrine therapy. This study investigated the efficacy of presurgical short-term endocrine therapy (preSTE) and assessed prognostic factors, including the preoperative endocrine prognostic index (PEPI) score. Methods: From October 2012 to November 2021, 269 postmenopausal women diagnosed with hormone receptor-positive (HR+), human epidermal growth factor receptor 2 negative breast cancer underwent endocrine therapy with a nonsteroidal aromatase inhibitor during the presurgical waiting period. The primary endpoint was to assess the changes in tumor size using ultrasonography, and Ki67 expression levels before and after preSTE. The secondary endpoint was the prognosis of patients categorized using the PEPI score. Results: The median age of patients was 68 years (range, 41-89 years). The median tumor size was 1.65 cm (range, 0.4-7.5 cm). The average pretreatment Ki67 expression level was 10% (range, 0%-90%). The median duration of endocrine therapy was 39 days (range, 2-88 days). Tumor diameter and Ki67 expression levels were significantly decreased to 1.43 cm (range, 0.45-5.83 cm) and 3.0% (range, 0%-85%) after preSTE, respectively. After the median observation period of 928 days, patients with PEPI scores ≥ 4 showed worse disease-free survival compared with those with lower PEPI scores. In terms of mortality, patients with PEPI score ≥ 4 had worse overall survival than did patients with lower PEPI scores. Conclusions: Endocrine therapy during the waiting period for surgery might be effective in reducing tumor size, and the Ki67 expression level and PEPI score might be useful in predicting the prognosis of patients with postmenopausal HR+ breast cancer.

Clinical efficacy of combined goserelin and anastrozole in neoadjuvant endocrine therapy for premenopausal women with hormone receptor-positive breast cancer

OBJECTIVE

The objective of this study is to assess the efficacy and safety of combining goserelin with anastrozole in neoadjuvant endocrine therapy (NET) for patients diagnosed with premenopausal breast cancer.

METHODS

A retrospective analysis was conducted on the clinicopathological data of 34 patients diagnosed with premenopausal breast cancer who underwent NET in the Department of Breast Surgery at Baotou Cancer Hospital between March 2016 and December 2019. Additionally, the feasibility of using goserelin combined with anastrozole for premenopausal endocrine therapy was assessed.

RESULTS

The duration of NET ranged from 6 to 72 months, with a mean of 22.5 months and a median of 18 months. In patients with progressive disease, endocrine therapy was assessed over a period of 6 to 18 months, with a mean of 13.1 months and a median of 13 months. Among the 28 patients assessed, 12 (42.86%) were found to have stable disease, subsequently receiving chemotherapy. Of these, seven patients demonstrated good compliance, and 5 achieved a pathological complete response. Including the 2 patients who responded favorably to NET alone, a total of 7 patients attained a pathological complete response. Additionally, 16 patients achieved complete cell cycle arrest following treatment. A significant correlation was observed between the clinical efficacy assessment and the pathological assessment of NET (P < 0.05).

CONCLUSION

Although NET was safe for patients diagnosed with premenopausal breast cancer, it should not be considered in isolation from chemotherapy. Transitioning to chemotherapy in a timely manner can significantly enhance treatment outcomes. The duration of NET should be guided by clinical assessment rather than being constrained by a predetermined time frame.

Surgical outcomes of neoadjuvant endocrine treatment in early breast cancer: meta-analysis

BACKGROUND

Neoadjuvant endocrine therapy presents an important downstaging option with lower toxicity than neoadjuvant chemotherapy in oestrogen receptor (ER)-positive early breast cancer. Meta-analysis of the effects of neoadjuvant endocrine therapy on surgical outcomes across randomized clinical trials (RCTs) and cohort studies has not previously been performed.

METHODS

A systematic review and meta-analysis was performed to evaluate the effect of neoadjuvant endocrine therapy on surgical outcomes (PROSPERO (international prospective register of systematic reviews, 2020)) compared with surgery followed by adjuvant endocrine therapy. PubMed and EMBASE were searched to identify RCT and cohort studies between 1946 and 27 March 2024. Two independent reviewers manually screened the identified records and extracted the data. Risk of bias was assessed using the Cochrane Collaboration tools and random-effects meta-analysis was done with ReviewManager.

RESULTS

The search identified 2390 articles eligible for screening. The review included 20 studies (12 cohort and 8 RCTs); 19 were included in the meta-analysis with a total of 6382 patients. Overall, neoadjuvant endocrine therapy was associated with a lower mastectomy rate compared with surgery first (risk ratio (RR) 0.53, 95% c.i. 0.44 to 0.64). Subgroup analysis showed similar improvement in the mastectomy rate in the neoadjuvant endocrine therapy group versus control group irrespective of study type (RCT: RR 0.58, 95% c.i. 0.50 to 0.66; cohorts: RR 0.48, 95% c.i. 0.33 to 0.70). There was no difference in the mastectomy rate by duration of neoadjuvant endocrine therapy (more than 4 months: RR 0.57, 95% c.i. 0.42 to 0.78; 4 months or less than 4 months: RR 0.52, 95% c.i. 0.43 to 0.64). Most of the studies were characterized by moderate-quality evidence with significant heterogeneity.

CONCLUSION

Neoadjuvant endocrine therapy is associated with a reduction in mastectomy rate. Given the moderate methodological quality of previous studies, further RCTs are required.

REGISTRATION ID

CRD42020209257.

Neoadjuvant Therapy: Current Landscape and Future Horizons for ER-Positive/HER2-Negative and Triple-Negative Early Breast Cancer

OPINION STATEMENT

Navigating the complex landscape of breast cancer treatment involves distinct strategies for luminal and triple-negative subtypes. While neoadjuvant chemotherapy historically dominates the approach for aggressive triple-negative tumors, recent evidence highlights the transformative impact of immunotherapy, alongside chemotherapy, in reshaping treatment paradigms. In luminal cancers, endocrine therapy, notably aromatase inhibitors, demonstrates promising outcomes in postmenopausal patients with low-grade luminal A tumors. However, integrating targeted therapies like CDK4/6 inhibitors in neoadjuvant setting remains inconclusive. Identifying predictive factors for treatment response, especially in luminal tumors, poses a challenge, emphasizing the necessity for ongoing research. A multidisciplinary approach, tailored to individual patient profiles, is crucial for maximizing efficacy while minimizing toxicity. As we strive to optimize breast cancer management, a comprehensive understanding of the distinct characteristics and treatment implications of luminal and triple-negative subtypes, including the transformative role of immunotherapy, is essential for informed decision-making and personalized care.

A Research Protocol for a Phase II Single-Arm Clinical Trial Assessing the Feasibility and Efficacy of Neoadjuvant Anastrozole in Patients With Luminal Breast Cancer and Low Proliferative Index: The ANNE Trial

INTRODUCTION

Neoadjuvant endocrine therapy (NET) is recommended for the treatment of invasive breast cancer (BC), particularly luminal subtypes, in locally advanced stages. Previous randomized studies have demonstrated the benefits of aromatase inhibitors in this context. However, NET is typically reserved for elderly or frail patients who may not tolerate neoadjuvant chemotherapy. Identifying non-responsive patients early and extending treatment for responsive ones would be ideal, yet optimal strategies are awaited.

AIMS

This non-randomized phase 2 clinical trial aims to assess NET feasibility and efficacy in postmenopausal stage II and III luminal BC patients, identifying predictive therapeutic response biomarkers. Efficacy will be gauged by patients with Ki67 ≤ 10% after 4 weeks and Preoperative Endocrine Prognostic Index (PEPI) scores 0 post-surgery. Study feasibility will be determined by participation acceptance rate (recruitment rate ≥50%) and inclusion rate (>2 patients/month).

METHODS

Postmenopausal women with luminal, HER2-tumors in stages II and III undergo neoadjuvant anastrozole treatment, evaluating continuing NET or receiving chemotherapy through early Ki67 analysis after 2 to 4 weeks. The study assesses NET extension for up to 10 months, using serial follow-ups with standardized breast ultrasound and clinical criteria-based NET suspension. Clinical and pathological responses will be measured overall and in the luminal tumor A subgroup. Toxicity, health-related quality of life, and circulating biomarkers predicting early NET response will also be evaluated.

Bridging pre-surgical endocrine therapy for breast cancer during the COVID-19 pandemic: outcomes from the B-MaP-C study

PURPOSE

The B-MaP-C study investigated changes to breast cancer care that were necessitated by the COVID-19 pandemic. Here we present a follow-up analysis of those patients commenced on bridging endocrine therapy (BrET), whilst they were awaiting surgery due to reprioritisation of resources.

METHODS

This multicentre, multinational cohort study recruited 6045 patients from the UK, Spain and Portugal during the peak pandemic period (Feb-July 2020). Patients on BrET were followed up to investigate the duration of, and response to, BrET. This included changes in tumour size to reflect downstaging potential, and changes in cellular proliferation (Ki67), as a marker of prognosis.

RESULTS

1094 patients were prescribed BrET, over a median period of 53 days (IQR 32-81 days). The majority of patients (95.6%) had strong ER expression (Allred score 7-8/8). Very few patients required expedited surgery, due to lack of response (1.2%) or due to lack of tolerance/compliance (0.8%). There were small reductions in median tumour size after 3 months' treatment duration; median of 4 mm [IQR - 20, 4]. In a small subset of patients (n = 47), a drop in cellular proliferation (Ki67) occurred in 26 patients (55%), from high (Ki67 ≥ 10%) to low (< 10%), with at least one month's duration of BrET.

DISCUSSION

This study describes real-world usage of pre-operative endocrine therapy as necessitated by the pandemic. BrET was found to be tolerable and safe. The data support short-term (≤ 3 months) usage of pre-operative endocrine therapy. Longer-term use should be investigated in future trials.

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.

Biomarker Alteration after Neoadjuvant Endocrine Therapy or Chemotherapy in Estrogen Receptor-Positive Breast Cancer

In estrogen receptor (ER)-positive breast cancer, changes in biomarker expression after neoadjuvant therapy indicate the therapeutic response and are prognostic. However, there is limited information about the biomarker alteration caused by neoadjuvant endocrine therapy in ER-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer. We recruited ER-positive/HER2-negative breast cancer patients who received neoadjuvant chemotherapy (NCT), neoadjuvant endocrine therapy (NET), or sequential neoadjuvant endocrine-chemotherapy (NECT) at Peking University Cancer Hospital from 2015 to 2021. A total of 579 patients had paired immunohistochemistry information in both diagnostic biopsy samples and post-neoadjuvant therapy surgical samples. Through a paired comparison of the immunohistochemical information in pre-treatment and post-treatment samples, we found that progesterone receptor (PR) expression reductions were more frequent than ER expression reductions (70.8% vs. 35.2%) after neoadjuvant therapy. The percentage of patients who had a decreased Ki-67 index in the post-operative samples was similar in the three groups (79.8% vs. 79.7% vs. 78.4%). Moreover, PR losses caused by NET were related to low baseline PR expression (p = 0.001), while we did not find a significant association between PR losses and Ki-67 reductions (p = 0.428) or ER losses (p = 0.274). All three types of neoadjuvant therapies caused a reduction in ER, PR, and Ki-67 expression. In conclusion, we found that PR loss after NET was only significantly related to low baseline PR expression, and there is no significant difference in the extent of prognostic factor change including Ki-67 and ER between the PR loss and non-loss groups.

Survival comparison between postoperative and preoperative radiotherapy for stage I-III non-inflammatory breast cancer

To compare the survival benefit between preoperative and postoperative radiotherapy for stage I-III non-inflammatory breast cancer patients, we conducted a retrospective cohort study using surveillance, epidemiology and end results databases. Our study recruited patients who had been diagnosed with stage I-III breast cancer and underwent surgery and radiotherapy. The overall survival was calculated by Kaplan-Meier method. Cox risk model was used to determine the impact of radiotherapy according to stage, molecular subtype and other risk factors. Propensity score matching was used to balance measurable confounding factors. Of all the 411,279 enrolled patients varying from 1975 to 2016, 1712 patients received preoperative radiotherapy, and 409,567 patients received postoperative radiotherapy. Compared with the postoperative radiotherapy group, the preoperative radiotherapy group showed significantly higher risks of overall mortality and breast cancer-specific mortality. Survival differences in treatment sequences were correlated with stage, molecular subtypes and other risk factors. According to the results of this study, preoperative radiotherapy did not show a survival advantage, and postoperative radiotherapy is still the primary treatment. However, preoperative radiotherapy also has some theoretical advantages, such as phase reduction and recurrence reduction. Therefore, it is still worthy of further exploration.

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.

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 in women with operable breast cancer: A retrospective analysis of real-world use

BACKGROUND

A retrospective study of the real-world use of neoadjuvant endocrine therapy (NET) is important for standardizing its role in breast cancer care.

MATERIALS AND METHODS

In a consecutive series of women with operable breast cancer who received NET for ≥28 days, NET objectives, NET outcomes, adjuvant chemotherapy use after NET, and survivals, were examined for the correlation with clinicopathological factors.

RESULTS

NET objectives were for surgery extent reduction in 49 patients, surgery avoidance in 31, and treatment until scheduled surgery in 8. The mean duration of NET was 349.5 (range, 34-1923), 869.8 (range, 36-4859), and 55.8 (range, 39-113) days in the above cohorts (success: 79.6%, 64.5%, and 100%), respectively, with significant difference. In patients of the former two cohorts, better progression-free survival was significantly correlated with stage 0 or I, ductal carcinoma in situ or invasive ductal carcinoma, ≥71% estrogen receptor (ER) positivity, and the surgery extent reduction cohort than the other counterparts. Postoperative chemotherapy use was significantly correlated with lymph node metastasis, a high Ki67 labeling index, lymphovascular invasion, and a high Preoperative Endocrine Prognostic Index, at surgery after NET. Better recurrence-free survival after surgery was significantly correlated with high ER expression after NET and high PgR expression before and after NET.

CONCLUSIONS

NET can help to reduce the surgery extent or to avoid surgery in women with breast cancer of early-stage, ductal carcinoma, or high ER expression. NET may also contribute to appropriate decision of postoperative systemic therapy to improve survivals.

Neoadjuvant Chemotherapy or Endocrine Therapy for Invasive Ductal Carcinoma of the Breast With High Hormone Receptor Positivity and Human Epidermal Growth Factor Receptor 2 Negativity

IMPORTANCE

Although neoadjuvant endocrine therapy (NET) is an alternative to chemotherapy for strongly hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (ERBB2)-negative breast cancer, evidence is currently lacking regarding the probable survival outcomes of NET in comparison with those of neoadjuvant chemotherapy (NACT) for this cancer.

OBJECTIVE

To evaluate all-cause mortality among patients with strongly HR-positive and ERBB2-negative breast cancer treated with NET vs NACT.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included patients with a diagnosis of invasive ductal carcinoma (IDC) with strong HR positivity and ERBB2 negativity, treated between January 1, 2009, and December 31, 2016, with follow-up from the index date (ie, date of IDC diagnosis) to December 31, 2018. The data came from the Taiwan Cancer Registry Database. Data were analyzed from January to November 2020.

EXPOSURES

NET vs NACT for IDC with strong HR positivity and ERBB2 negativity.

MAIN OUTCOMES AND MEASURES

The primary end point was all-cause mortality. Propensity score matching was performed, and Cox proportional hazard models were used to analyze all-cause mortality among patients undergoing different neoadjuvant treatments.

RESULTS

A total of 640 patients (297 [46.4%] aged 20-49 years) undergoing NET (145 patients [22.7%]) or NACT (495 patients [77.3%]) were eligible for further analysis. In the multivariate Cox regression analyses, the adjusted hazard ratio (aHR) for all-cause mortality among the NET cohort compared with the NACT cohort was 2.67 (95% CI, 1.95-3.51; P < .001). The aHRs for age were 1.13 (95% CI, 1.03-2.24), 1.25 (95% CI, 1.13-2.45), and 1.37 (95% CI, 1.17-3.49) for all-cause mortality among patients aged 50 to 59, 60 to 69, and 70 years or older, respectively, compared with those aged 20 to 49 years (P = .002); the aHR for all-cause mortality among premenopausal women was 1.35 (95% CI, 1.13-1.56) compared with postmenopausal women (P < .001); and that of patients with a Charlson Comorbidity Index score of 2 or greater was 1.77 (1.37-2.26) compared with those with a score of 0 (P < .001). The aHRs of all-cause mortality for clinical tumor stage 2, 3, and 4 compared with 1 were 1.84 (95% CI, 1.07-3.40), 1.97 (95% CI, 1.03-3.77), and 2.49 (95% CI, 1.29-4.81), respectively (P = .009). The aHRs for all-cause mortality by clinical nodal (cN) stages were 1.49 (95% CI, 1.13-1.99) and 1.84 (95% CI, 1.31-2.61) for cN stage 1 and cN stages 2 or 3, respectively, compared with cN stage 0 (P = .005); those for differentiation were 1.77 (95% CI, 1.24-2.54) and 2.31 (95% CI, 1.61-3.34) for differentiation grade 2 and differentiation grade 3, respectively, compared with differentiation grade 1 (P < .001).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that for patients with strongly HR-positive and ERBB2-negative IDC, NACT may be considered the first choice for neoadjuvant treatment.

Real-world data on neoadjuvant endocrine therapy in ER-positive/HER2-negative breast cancer

PURPOSE

Neoadjuvant endocrine therapy (NET) has been shown to be effective in ER-positive/HER2-negative breast cancer in clinical trials. However, adoption in clinical practice is still limited. Real-world data may provide useful insights into effectiveness, toxicities and quality of care, potentially rendering clinical trial results to the real-world setting. Our purpose was to report real-world data of a cohort of postmenopausal patients submitted to NET.

METHODS

This prospective cohort study evaluated 146 postmenopausal female patients with ER-positive/HER2-negative breast cancer treated with NET at three tertiary hospitals between 2016 and 2018. Clinicopathological information were collected prospectively. Preoperative Endocrine Prognostic Index (PEPI) score was calculated for tumors submitted to at least 16 weeks of NET.

RESULTS

Median age was 67 years old, and 87.8% had stage I-II disease. Most tumors had histological grade II (76.1%). Median pretreatment Ki67 expression was 10%. Aromatase inhibitor was used in 99.5% of patients, and median treatment duration was 21.0 weeks. No tumor progressed during NET. Breast-conserving surgery was performed in the majority of patients (63.0%), as well as sentinel lymph-node biopsy (76.7%). Pathological complete response rate was 1.0%. 43 patients (29.5%) had PEPI score 0, and 26% had PEPI scores 4-5. Posttreatment Ki67 median expression was 3.0%, and only five tumors (3.4%) showed marked increase in Ki67 expression during treatment. Seven patients (4.8%) had HER2-positive residual disease, and were treated with adjuvant chemotherapy plus trastuzumab.

CONCLUSIONS

Our real-world data shows that NET is effective and safe in postmenopausal patients with ER-positive/HER2-negative breast cancer. Postmenopausal status and low-risk luminal tumor features (luminal A-like) should be used as selection criteria to ensure the best results with NET.

Optimal Treatment Duration of Neoadjuvant Endocrine Therapy for Women Aged 60 Years or Older with Estrogen Receptor-Positive, HER2-Negative Invasive Breast Cancer

BACKGROUND

Neoadjuvant endocrine therapy is not the standard of care for breast cancer, primarily because the optimal treatment duration remains unclear. This phase 2 prospective multicenter study analyzed time to progression, time to maximal response, and time to treatment failure for neoadjuvant exemestane.

METHODS

Inclusion criteria were women aged ≥60 years with Stage II or III breast cancer classified as estrogen receptor-positive/human epidermal growth factor receptor 2-negative. Response was defined as a ≥10% and minimum of 3 mm decrease in tumor size, as compared with the most recent or smallest value, and no new lesion. Progression was defined as a >10% and minimum of over 3 mm increase in tumor size, as compared with the most recent or smallest value, or a new lesion. Maximal response was defined as the final recorded response.

RESULTS

This study included 24 women, most of whom had T2 N0 tumors with high estrogen receptor expression. We initially observed a response in 23 patients (96%); however, 6 patients (25%) later experienced progression. Time to progression, time to maximal response, and time to treatment failure ranged from 7 to 22 months (estimated median, 35), 1 to 22 months (estimated median, 10), and 2 to 22 months (estimated median, 22), respectively. Treatment duration varied widely, but the estimated optimal duration of neoadjuvant exemestane therapy was 22 to 35 months in patients seeking to avoid surgery and 10 months in patients wishing to receive breast-conserving surgery.

CONCLUSIONS

Neoadjuvant exemestane therapy is long effective for older women with hormone-sensitive breast cancer.

How Effective is Neoadjuvant Endocrine Therapy (NET) in Downstaging the Axilla and Achieving Breast-Conserving Surgery?

BACKGROUND

Neoadjuvant endocrine therapy (NET) is effective in downstaging large hormone receptor-positive (HR+) breast cancers and increasing rates of breast-conserving surgery (BCS), but data regarding nodal pathologic complete response (pCR) are sparse. We reported nodal and breast downstaging rates with NET, and compared axillary response rates following NET and neoadjuvant chemotherapy (NAC).

METHODS

Consecutive stage I-III breast cancer patients treated with NET and surgery from January 2009 to December 2019 were identified from a prospectively maintained database. Nodal pCR rates were compared between biopsy-proven node-positive patients treated with NET, and HR+/HER2- patients treated with NAC from November 2013 to July 2019.

RESULTS

127 cancers treated with NET and 338 with NAC were included. NET recipients were older, more likely to have lobular and lower-grade tumors, and higher HR expression. With NET, the nodal pCR rate was 11% (4/38) of biopsy-proven cases, and the breast pCR rate was 1.6% (2/126). Nodal-dowstaging rates with NET and NAC were not significantly different (11% vs 18%; P = 0.37). Patients achieving nodal pCR with NET versus NAC were older (median age 70 vs 50, P = 0.004) and had greater progesterone receptor (PR) expression (85% vs 13%, P = 0.031), respectively. Of patients not candidates for BCS due to a large tumor relative to breast size, 36/47 (77%) became BCS-eligible with NET (median PR expression 55% vs 5% in those remaining ineligible, P < 0.05).

CONCLUSION

Although nodal pCR is more frequent than breast pCR, NET is more likely to de-escalate breast surgery than axillary surgery. However, with a nodal pCR rate of 11%, NET remains an option for downstaging node-positive patients without clear indications for NAC.

Neoadjuvant endocrine therapy in locally advanced estrogen or progesterone receptor-positive breast cancer: determining the optimal endocrine agent and treatment duration in postmenopausal women-a literature review and proposed guidelines

Introduction

For patients with locally advanced estrogen receptor or progesterone receptor-positive breast cancer, neoadjuvant endocrine therapy (NET) facilitates down-staging of the tumor and increased rates of breast-conserving surgery. However, NET remains under-utilized, and there are very limited clinical guidelines governing which therapeutic agent to use, or the optimal duration of treatment in postmenopausal women. This literature review aims to discuss the evidence surrounding (1) biomarkers for patient selection for NET, (2) the optimal neoadjuvant endocrine agent for postmenopausal women with locally advanced breast cancer, and (3) the optimal duration of NET. In addition, we make initial recommendations towards developing a clinical guideline for the prescribing of NET.

Method

A wide-ranging search of online electronic databases was conducted using a truncated PIC search strategy to identify articles that were relevant to these aims and revealed a number of key findings.

Results

Randomized trials have consistently demonstrated that aromatase inhibitors are more effective than tamoxifen, in terms of objective response rate and rate of BCS, and should be used as first-line NET. The three available aromatase inhibitors have so far been demonstrated to be biologically equivalent, with the choice of aromatase inhibitor not having been shown to affect clinical outcomes. There is increasing evidence for extending the duration of NET beyond 3 to 4 months, to at least 6 months or until maximal clinical response is achieved. While on-treatment levels of the proliferation marker Ki67 are predictive of long-term outcome, the choice of adjuvant therapy in patients who have received NET and then surgery is best guided by the preoperative endocrine prognostic index, or PEPI, which incorporates Ki67 with other clinical parameters.

Conclusion

This study reveals that in appropriately selected patients, NET can provide equivalent clinical benefit to neoadjuvant chemotherapy in the same cohort, if suitable treatments and durations are chosen. Our findings highlight the need for better defined biomarkers both for guiding patient selection and for measuring outcomes. Development of standard guidelines for the prescribing of NET has the potential to improve both clinical outcomes and quality of life in this patient cohort.

Metronomic chemotherapy combined with endocrine therapy: are we challenging some dogmas?

INTRODUCTION

Metronomic chemotherapy exerts its effects via inhibition of angiogenesis, immune modulation of the tumoral stroma, induction of senescence and apoptosis of tumor cells. Due to its favorable toxicity profile and its oral administration, metronomic chemotherapy arises as a promising alternative to be combined with endocrine therapy for the treatment of patients with luminal breast cancer.

AREAS COVERED

The present manuscript reviews the rationale supporting the combination of metronomic chemotherapy and endocrine therapy, discussing the studies that evaluated this regimen in the treatment of early-stage and metastatic breast cancer patients. Finally, we conclude by providing an expert opinion on the current role and perspectives for the combination of metronomic chemotherapy and endocrine therapy in the management of patients with luminal breast cancer.

EXPERT OPINION

Retrospective series and early-phase clinical trials have shown promising signs of activity and a favorable toxicity profile with this regimen, which warrants further investigation as a treatment option for luminal breast cancer patients.

Breast Cancer Management Guidelines During COVID-19 Pandemic

The coronavirus disease (COVID-19) pandemic in 2020 has brought about complex challenges in healthcare delivery. With the new rules of lockdown and social distancing and with resources diverted to the management of COVID-19, there are difficulties in continuing usual cancer care. Patients are at risk of contracting COVID-19 with a high chance of patient to healthcare transmission and vice versa. Hospital visits, investigations and all modalities of treatment have potential complications that put patients at risk, some more than others. In this situation, there is a need to change our approach in the management of breast cancer to deliver it safely. We present modified guidelines based on the available consensus statements and evidence.

Preparing for the renaissance: treating breast cancer during the COVID-19 pandemic and planning for a safe re-emergence to routine surgical care within a universal health care system

The evolving covid-19 pandemic is placing tremendous pressure on health systems. [...]

Neoadjuvant Endocrine Therapy in Breast Cancer: Current Knowledge and Future Perspectives

In locally advanced (LA) breast cancer (BC), neoadjuvant treatments have led to major achievements, which hold particular relevance in HER2-positive and triple-negative BC. Conversely, their role in hormone receptor positive (HR+), hormone epidermal growth factor 2 negative (HER2-) BC is still under debate, mainly due to the generally low rates of pathological complete response (pCR) and lower accuracy of pCR as predictors of long-term outcomes in this patient subset. While administration of neoadjuvant chemotherapy (NCT) in LA, HR+, HER2- BC patients is widely used in clinical practice, neoadjuvant endocrine therapy (NET) still retains an unfulfilled potential in the management of these subgroups, particularly in elderly and unfit patients. In addition, NET has gained a central role as a platform to test new drugs and predictive biomarkers in previously untreated patients. We herein present historical data regarding Tamoxifen and/or Aromatase Inhibitors and a debate on recent evidence regarding agents such as CDK4/6 and PI3K/mTOR inhibitors in the neoadjuvant setting. We also discuss key issues concerning the optimal treatment length, appropriate comparisons with NCT efficacy and use of NET in premenopausal patients.

Neoadjuvant letrozole plus taselisib versus letrozole plus placebo in postmenopausal women with oestrogen receptor-positive, HER2-negative, early-stage breast cancer (LORELEI): a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial

BACKGROUND

Endocrine therapy-based neoadjuvant treatment for luminal breast cancer allows efficient testing of new combinations before surgery. The activation of the phosphatidylinositol-3-kinase (PI3K) pathway is a known mechanism of resistance to endocrine therapy. Taselisib is an oral, selective PI3K inhibitor with enhanced activity against PIK3CA-mutant cancer cells. The LORELEI trial tested whether taselisib in combination with letrozole would result in an increased proportion of objective responses and pathological complete responses.

METHODS

In this multicentre, randomised, double-blind, parallel-cohort, placebo-controlled phase 2, study, we enrolled postmenopausal women (aged ≥18 years) with histologically confirmed, oestrogen receptor (ER)-positive, HER2-negative, stage I-III, operable breast cancer, from 85 hospitals in 22 countries worldwide. To be eligible, patients had have an Eastern Cooperative Oncology Group (ECOG) performance status 0-1, adequate organ function, and had to have evaluable tumour tissue for PIK3CA genotyping. Patients were randomly assigned (1:1) by means of a permuted block algorithm (block size of four) via an interactive voice or web-based response system, to receive letrozole (2·5 mg/day orally, continuously) with either 4 mg of oral taselisib or placebo (on a 5 days-on, 2 days-off schedule) for 16 weeks, followed by surgery. Randomisation was stratified by tumour size and nodal status. Site staff, patients, and the sponsor were masked to treatment assignment. Coprimary endpoints were the proportion of patients who achieved an objective response by centrally assessed breast MRI and a locally assessed pathological complete response in the breast and axilla (ypT0/Tis, ypN0) at surgery in all randomly assigned patients and in patients with PIK3CA-mutant tumours. Analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02273973, and is closed to accrual.

FINDINGS

Between Nov 12, 2014, and Aug 12, 2016, 334 participants were enrolled and randomly assigned to receive letrozole and placebo (n=168) or letrozole and taselisib (n=166). Median follow-up was 4·9 months (IQR 4·7-5·1). The study met one of its primary endpoints: the addition of taselisib to letrozole was associated with a higher proportion of patients achieving an objective response in all randomly assigned patients (66 [39%] of 168 patients in the placebo group vs 83 [50%] of 166 in the taselisib group; odds ratio [OR] 1·55, 95% CI 1·00-2·38; p=0·049) and in the PIK3CA-mutant subset (30 [38%] of 79 vs 41 [56%] of 73; OR 2·03, 95% CI 1·06-3·88; p=0·033). No significant differences were observed in pathological complete response between the two groups, either in the overall population (three [2%] of 166 in the taselisib group vs one [1%] of 168 in the placebo group; OR 3·07 [95% CI 0·32-29·85], p=0·37) or in the PIK3CA-mutant cohort (one patient [1%) vs none [0%]; OR not estimable, p=0·48). The most common grade 3-4 adverse events in the taselisib group were gastrointestinal (13 [8%] of 167 patients), infections (eight [5%]), and skin-subcutaneous tissue disorders (eight [5%]). In the placebo group, four (2%) of 167 patients had grade 3 or worse vascular disorders, two (1%) had gastrointestinal disorders, and two (1%) patients had grade 3 or worse infections and infestations. There was no grade 4 hyperglycaemia and grade 3 cases were asymptomatic. Serious adverse events were more common in the taselisib group (eight [5%] patients with infections and seven [4%] with gastrointestinal effects) than in the placebo group (one [1%] patient each with grade 3 postoperative wound and haematoma infection, grade 4 hypertensive encephalopathy, grade 3 acute cardiac failure, and grade 3 breast pain). One death occurred in the taselisib group, which was not considered to be treatment-related.

INTERPRETATION

The increase in the proportion of patients who achieved an objective response from the addition of taselisib to endocrine therapy in a neoadjuvant setting is consistent with the clinical benefit observed in hormone receptor-positive, HER2-negative, metastatic breast cancer.

FUNDING

Genentech and F Hoffmann-La Roche.

Cyclin-Dependent Kinase 4/6 Inhibitors in Neoadjuvant Endocrine Therapy of Hormone Receptor-Positive Breast Cancer

The landscape of therapeutic options for the treatment of hormone receptor (HR)-positive (HR⁺) HER2^- breast cancer (BC) has been profoundly changed by the introduction of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors into the metastatic setting. Currently all CDK4/6 inhibitors are approved only in the metastatic setting by Food and Drug Administration (FDA) and European Medicine Agency (EMA), whereas their role in the neoadjuvant setting is still at an investigational stage. Exploitation of novel agents such as CDK4/6 inhibitors to improve the efficacy of neoadjuvant endocrine therapy (ET) or to overcome de novo resistance to ET is an area of research under active evaluation. We present a review of the currently available data and ongoing clinical trials that are evaluating the role of CDK4/6 inhibitors in neoadjuvant therapy of HR⁺ HER2^- early BC, and also illustrate translational aspects, such as the potential biomarkers of response to these new therapeutic agents.

A Phase II Randomized Study of Neoadjuvant Letrozole Plus Alpelisib for Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer (NEO-ORB)

PURPOSE

Addition of alpelisib to fulvestrant significantly extended progression-free survival in PIK3CA-mutant, hormone receptor-positive (HR+) advanced/metastatic breast cancer in the phase III SOLAR-1 study. The combination of alpelisib and letrozole also had promising activity in phase I studies of HR+ advanced/metastatic breast cancer. NEO-ORB aimed to determine whether addition of alpelisib to letrozole could increase response rates in the neoadjuvant setting.Patients and Methods: Postmenopausal women with HR+, human epidermal growth factor receptor 2-negative, T1c-T3 breast cancer were assigned to the PIK3CA-wild-type or PIK3CA-mutant cohort according to their tumor PIK3CA status, and randomized (1:1) to 2.5 mg/day letrozole with 300 mg/day alpelisib or placebo for 24 weeks. Primary endpoints were objective response rate (ORR) and pathologic complete response (pCR) rate for both PIK3CA cohorts.

RESULTS

In total, 257 patients were assigned to letrozole plus alpelisib (131 patients) or placebo (126 patients). Grade ≥3 adverse events (≥5% of patients) in the alpelisib arm were hyperglycemia (27%), rash (12%), and maculo-papular rash (8%). The primary objective was not met; ORR in the alpelisib versus placebo arm was 43% versus 45% and 63% versus 61% in the PIK3CA-mutant and wild-type cohorts, respectively. pCR rates were low in all groups. Decreases in Ki-67 were similar across treatment arms and cohorts. In PIK3CA-mutant tumors, alpelisib plus letrozole treatment induced a greater decrease in phosphorylated AKT versus placebo plus letrozole.

CONCLUSIONS

In contrast to initial results in advanced/metastatic disease, addition of alpelisib to 24-week neoadjuvant letrozole treatment did not improve response in patients with HR+ early breast cancer.

Primary medical therapy and breast conservation treatment: the medical oncology perspective

Primary systemic therapy (PST) is a widely adopted strategy for increasing operability and breast conservation rates. Although first generation PST trials failed to demonstrate improvements in disease free and overall survival compared to adjuvant systemic therapy (AST), they did demonstrate a strong association between attainment of pathologic complete response (pCR) and improved survival outcomes, leading to the widespread adoption of pCR as the primary endpoint in subsequent PST trials. First generation trials also showed that preoperative PST can improve breast conservation rates and downstage the axilla. Although individual trials did not demonstrate statistically significant increase in local recurrence with PST when compared to AST, a recent meta-analysis did note an increased in such risk, mainly driven by trials in which surgery was omitted in patients with good response to PST. Successive generations of PST clinical trials have since explored the activity of taxanes, optimization of anthracycline and taxane dose and schedules, incorporation of single and dual anti-HER2 therapy in HER2 overexpressing breast cancer, the use of platinums in triple negative breast cancer, and the role of endocrine therapy in hormone receptor positive breast cancer. While these PST trials have generally found increased pCR rates with the introduction of modern chemotherapy regimens and targeted therapies, they have not consistently demonstrated further improvements in breast conservation rates compared to first generation regimens. The reasons for this are complex and may lie beyond differences in anti-tumour activity between different systemic regimens but rather in other potential confounding factors such as tumour to breast volume ratio, tumour location, multicentricity as well as patient or surgeon preference.

Neoadjuvant Therapy for Breast Cancer: Established Concepts and Emerging Strategies

In the last decade, the systemic treatment approach for patients with early breast cancer has partly shifted from adjuvant treatment to neoadjuvant treatment. Systemic treatment administration started as a 'one size fits all' approach but is currently customized according to each breast cancer subtype. Systemic treatment in a neoadjuvant setting is at least as effective as in an adjuvant setting and has several additional advantages. First, it enables response monitoring and provides prognostic information; second, it downstages the tumor, allowing for less extensive surgery, improved cosmetic outcomes, and reduced postoperative complications such as lymphedema; and third, it enables early development of new treatment strategies by using pathological complete remission as a surrogate outcome of event-free and overall survival. In this review we give an overview of the current standard of neoadjuvant systemic treatment strategies for the three main subtypes of breast cancer: hormone receptor-positive, triple-negative, and human epidermal growth factor receptor 2-positive. Additionally, we summarize drugs that are under investigation for use in the neoadjuvant setting.

Current Status of Neoadjuvant Endocrine Therapy in Early Stage Breast Cancer

OPINION STATEMENT

Neoadjuvant endocrine therapy (NET) with Ki67-based response monitoring is a practical, cost-effective approach to the management of clinical stage II and III estrogen receptor-positive (ER+) breast cancer. In addition to marked improvements in rates of breast conservation, the identification of extreme responders on the basis of the preoperative endocrine prognostic index (PEPI) provides a rationale to avoid chemotherapy on the basis of highly favorable prognosis in some patients. Finally, samples accrued from patients treated with neoadjuvant therapy are providing valuable insights into the molecular basis for intrinsic resistance to endocrine therapy and promise a more rational basis and precise approach to the systemic treatment of ER+ breast cancer.

Pre-surgical chemotherapy for breast cancer may be associated with improved outcomes

BACKGROUND

Historical studies suggest no difference in disease outcome between neoadjuvant and adjuvant approaches in breast cancer. We hypothesize neoadjuvant chemotherapy (NCT) may offer several benefits, possibly improving quality of life outcomes.

METHODS

Retrospective review of Tumor Registry data of breast cancer patients from 2011 to 2015. Pathologists reviewed cases from 2012 to 2013 to provide additional RCB (residual cancer burden) scores.

RESULTS

From 2011 to 2015 there were 2707 breast cancer cases and 455 patients received NCT. RCB score was documented in 348 with excellent outcome in 41% (pCR in 115 patients, 28 RCB I). There were 137 RCB II and 68 RCB III. Clinically positive nodes were present in 202 of 455 and 77 (38%) had clearance of nodal disease. Of these 45 had axillary dissections.

DISCUSSION

Neoadjuvant therapy was associated with excellent response rates. Thirty eight percent of patients with positive nodes converted to node negative although over 50% underwent axillary dissection. Higher utilization of NCT could decrease need for axillary dissection thereby lowering incidence of lymphedema and improving quality of life for survivors.

Neoadjuvant letrozole for postmenopausal estrogen receptor-positive, HER2-negative breast cancer patients, a study from the Danish Breast Cancer Cooperative Group (DBCG)

INTRODUCTION

Neoadjuvant endocrine treatment (NET) is a low-toxicity approach to achieve operability in locally advanced breast cancer, and to facilitate breast conservation in early breast cancer, particular in patients with highly estrogen receptor (ER) positive and HER2-negative disease. Here, we report the results obtained by neoadjuvant letrozole in patients with early breast cancer in a phase-II design.

MATERIAL AND METHODS

A total of 119 postmenopausal women with ER-positive, HER2-negative operable breast cancer were assigned to four months of neoadjuvant letrozole before definitive surgery. Sentinel node or diagnostic fine needle aspiration cytology procedure was performed prior to treatment and the women were assessed prior, at two months, and before surgery with clinical examination, mammography and ultrasonography. Surgical specimens were examined for pathological response. Primary outcome was pathological and clinical response.

RESULTS

The per protocol population consisted of 112 patients. Clinical response was evaluated in 109 patients and pathological response in 108. Overall a mean decrease in tumor size was 15% (p ≤ .0001). One patient had complete pathological response and 55% of patients had partial pathological response. ER at 100%, ductal subtype, tumor size below 2 cm and lymph node-negative status was significantly associated with a better response to NET and malignancy grade 3 with a poorer response to NET. One patient progressed during treatment and received neoadjuvant chemotherapy. Eight patients received adjuvant chemotherapy due to lack of response.

CONCLUSION

Neoadjuvant aromatase inhibitor therapy is an acceptable strategy in selected postmenopausal patients with ER-rich and HER2-negative early breast cancer with ductal histology and should be considered when chemotherapy either isn't indicated or feasible.

Neoadjuvant Endocrine Therapy: Who Benefits Most?

Neoadjuvant endocrine therapy (NET) can be effective at downstaging patients with estrogen receptor-positive tumors and identifying those tumors that are endocrine sensitive and resistant. The optimal prognostic markers for stratification are under investigation. Use of NET will allow the identification of patients with estrogen receptor-positive tumors who might benefit from additional treatment and allow better understanding of endocrine resistance.

Preoperative Endocrine Therapy

Purpose of Review

Pre-operative endocrine therapy can be used to down-stage large or locally advanced breast cancers in ER+ disease. In the last four decades, it has evolved from a treatment perceived as an alternative to surgery for those too unfit to undergo surgery or chemotherapy, to the present day where it is a valuable and valid option in the treatment of postmenopausal women with ER-rich (Allred score 7–8, or > 50% staining for ER) breast cancer.

Recent Findings

Emerging data from the metastatic setting is translating into neoadjuvant trials, utilising dual endocrine targeting or combinations of endocrine agents and other targeted drugs, including those acting against components of the PI3K pathway and the cell cycle. The routine use of peri-operative endocrine therapy in all ER+ tumours may help to yield important long-term prognostic information, and guide adjuvant endocrine therapy.

Summary

Pre-operative endocrine therapy is an exciting and evolving area with emerging new approaches. In this review, established evidence and emerging data on its applications are discussed.

Neoadjuvant endocrine therapy in breast cancer patients

HIGHLIGHTS

The overall response rate to neoadjuvant endocrine therapy (NET) was 54.55%.The eight patients proposed to tumour's downstage, after 9.71 months of NET, preserved their breast.In the group which achieved response, 10.28 months was the mean time to accomplish it.Even patients who had the worst outcome only began to suffer latter in the course of therapy.NET can be done beyond the conventional 3-4 months to allow additional downstage of the tumour.

BACKGROUND

The aim of this study is to evaluate if the extension of neoadjuvant endocrine therapy (NET), beyond the conventional time, allows additional downstage of the tumour, in order to perform a breast conservative surgery (BCS), and to analyze if it is a good option for long-term control in patients who refuse or are unfit for surgery.

PATIENTS AND METHODS

We retrospectively reviewed a database containing all patients treated in our institution with NET. All included patients were post-menopausal with primary local disease. The type of response obtained was assessed using modified RECIST criteria.

RESULTS

Thirty-three patients were included. Two patients had tumours with 90% expression of oestrogen receptors and all the others had 100%. The tumour size in the largest diameter was 6.51 cm before treatment and 5.18 cm after. Eighteen patients achieved a partial response after 10.28 months of therapy. Patients that were proposed to downstage the tumour performed 9.71 months of therapy until surgery and all were submitted to BCS. Progression occurred after 27.5 months.

CONCLUSION

Endocrine therapy is a feasible option for a longer time to allow additional downstage of the tumour and is a good solution in patients who refuse or are unfit for surgery.

Age-related Disparity: Breast Cancer in the Elderly

Aging poses an unique opportunity to study cancer biology and treatment in older adults. Breast cancer is often studied in young women; however, much investigation remains to be done on breast cancer in our expanding elderly population. Diagnostic and management strategies applicable to younger patients cannot be empirically used to manage older breast cancer patients. Lack of evidence-based data continues to be the major impediment toward delivery of personalized cancer care to elderly breast cancer patients. This article reviews the relevant literature on management of curable breast cancer in the elderly, the role of geriatric assessment, complex treatment decision making within the context of patient's expected life expectancy, comorbidities, physical function, socioeconomic status, barriers to health care delivery, goals of treatment, and therapy-related side effects. Continuing efforts for enrolling elderly breast cancer patients in contemporary clinical trials, and thus improving age-appropriate care, are emphasized.

Neoadjuvant Trials in ER+ Breast Cancer: A Tool for Acceleration of Drug Development and Discovery

Neoadjuvant therapy trials offer an excellent strategy for drug development and discovery in breast cancer, particularly in triple-negative and HER2-overexpressing subtypes, where pathologic complete response is a good surrogate of long-term patient benefit. For estrogen receptor-positive (ER+) breast cancers, however, use of this strategy has been challenging because of the lack of validated surrogates of long-term efficacy and the overall good prognosis of the majority of patients with this cancer subtype. We review below the clinical benefits of neoadjuvant endocrine therapy for ER+/HER2-negative breast cancer, its use and limitations for drug development, prioritization of adjuvant and metastatic trials, and biomarker discovery.Significance: Neoadjuvant endocrine therapy is an excellent platform for the development of investigational drugs, triaging of novel combinations, biomarker validation, and discovery of mechanisms of drug resistance. This review summarizes the clinical and investigational benefits of this approach, with a focus on how to best integrate predictive biomarkers into novel clinical trial designs. Cancer Discov; 7(6); 561-74. ©2017 AACR.

Neoadjuvant Endocrine Therapy for Estrogen Receptor-Positive Breast Cancer: A Systematic Review and Meta-analysis

Importance

Estrogen receptor-positive (ER+) tumors of the breast are generally highly responsive to endocrine treatment. Although endocrine therapy is the mainstay of adjuvant treatment for ER+ breast cancer, the role of endocrine therapy in the neoadjuvant setting is unclear.

Objective

To evaluate the effect of neoadjuvant endocrine therapy (NET) on the response rate and the rate of breast conservation surgery (BCS) for ER+ breast cancer.

Data Sources

Based on PRISMA guidelines, a librarian-led search of PubMed and Ovid MEDLINE was performed to identify eligible trials published from inception to May 15, 2015. The search was performed in May 2015.

Study Selection

Inclusion criteria were prospective, randomized, neoadjuvant clinical trials that reported response rates with at least 1 arm incorporating NET (n = 20). Two authors independently analyzed the studies for inclusion.

Data Extraction and Synthesis

Pooled odds ratios (ORs), 95% CIs, and P values were estimated for end points using the fixed- and random-effects statistical model.

Results

The analysis included 20 studies with 3490 unique patients. Compared with combination chemotherapy, NET as monotherapy with aromatase inhibitors had a similar clinical response rate (OR, 1.08; 95% CI, 0.50-2.35; P = .85; n = 378), radiological response rate (OR, 1.38; 95% CI, 0.92-2.07; P = .12; n = 378), and BCS rate (OR, 0.65; 95% CI, 0.41-1.03; P = .07; n = 334) but with lower toxicity. Aromatase inhibitors were associated with a significantly higher clinical response rate (OR, 1.69; 95% CI, 1.36-2.10; P < .001; n = 1352), radiological response rate (OR, 1.49; 95% CI, 1.18-1.89; P < .001; n = 1418), and BCS rate (OR, 1.62; 95% CI, 1.24-2.12; P < .001; n = 918) compared with tamoxifen. Dual combination therapy with growth factor pathway inhibitors was associated with a higher radiological response rate (OR, 1.59; 95% CI, 1.04-2.43; P = .03; n = 355), but not clinical response rate (OR, 0.76; 95% CI, 0.54-1.07; P = .11; n = 537), compared with endocrine monotherapy. The incidence of pathologic complete response was low (<10%).

Conclusions and Relevance

Neoadjuvant endocrine therapy, even as monotherapy, is associated with similar response rates as neoadjuvant combination chemotherapy but with significantly lower toxicity, suggesting that NET needs to be reconsidered as a potential option in the appropriate setting. Additional research is needed to develop rational NET combinations and predictive biomarkers to personalize the optimal neoadjuvant strategy for ER+ breast cancer.

Breast Cancer in Women Older Than 80 Years

Breast cancer is the most common cancer in women, with an incidence that rises dramatically with age. The average age at diagnosis of breast cancer is 61 years, and the majority of woman who die of breast cancer are age 65 years and older. Major improvements in public health and medical care have resulted in dramatic increases in longevity. The oldest old (those age 80 years and older) are a rapidly expanding group and now comprise 9 million members of the US population. The treatment of individuals who are age 80 years and older is complex and involves clearly defining the goals and value of treatment while also weighing risks, such as the potential effects of treatment on functional loss and quality of life. Limited evidence-based treatment guidelines exist for the caring of this older cohort of patients with breast cancer. Data from clinical trials that enroll primarily younger patients lack the information needed to estimate the likelihood of toxicities that can be life changing in older adults. Clinicians who make treatment recommendations should place the available evidence in the context of the patient's life expectancy and geriatric assessment results that include an evaluation of a patient's functional status, comorbidities, cognition, social support, nutritional status, and psychological state. Furthermore, these decisions should be placed in the context of the patient's goals for treatment, preferences, and values. This review summarizes the current literature and focuses on the role of geriatric assessment in treatment recommendations for patients age 80 years and older with early and metastatic breast cancer.

[Systemic neoadjuvant therapy of luminal breast cancer in 2016]

Neoadjuvant systemic therapies have been extensively evaluated in luminal breast cancer. Conventional cytotoxic chemotherapy increases breast conservation rate, albeit with a low level of complete pathological response of uncertain clinical significance. Endocrine therapies allow similar clinical results with much less side effects. Biological criteria of response to endocrine therapies are still being defined. The neoadjuvant setting must be used for early development of new compounds and to further document biological mechanisms of sensitivity and resistance to treatments.

Adjuvant systemic therapy in older women with breast cancer

Breast cancer in the elderly is an increasing clinical problem. In addition, ~60% of deaths from breast cancer occur in women aged 65 years and older. Despite this, older women with breast cancer have been underrepresented in clinical trials, and this has led to less than optimal evidence to guide their therapy. The management of elderly women with early breast cancer is a complex process that requires careful evaluation of life expectancy, comorbidities, patient values, and risks and benefits of available treatment options. This review will focus on current adjuvant systemic therapy options for older women with breast cancer, discuss the principles in the decision-making process, and define the role of endocrine therapy, chemotherapy, and targeted agents.

Randomized phase 2 neoadjuvant trial evaluating anastrozole and fulvestrant efficacy for postmenopausal, estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer patients: Results of the UNICANCER CARMINA 02 French trial (UCBG 0609)

BACKGROUND

Treatment strategies for locally advanced breast cancer in elderly patients too frail to receive neoadjuvant chemotherapy and the introduction of new classes of drugs in the early 2000s have led to the consideration of endocrine therapy as a neoadjuvant treatment for younger hormone receptor (HR)-positive, postmenopausal patients not eligible for primary breast-conserving surgery (BCS).

METHODS

This was a multicenter, phase 2, randomized trial designed to evaluate as its primary objective the clinical response rate after up to 6 months of neoadjuvant endocrine therapy (NET) alone in HR-positive/human epidermal growth factor receptor 2 (HER2)-negative patients with 1 mg of anastrozole (arm A) or 500 mg of fulvestrant (arm B). Secondary objectives included the BCS rate, tumor response assessment (breast ultrasound and magnetic resonance imaging), pathological response (Sataloff classification), safety profile, relapse-free survival (RFS), and predictive markers of responses and outcomes.

RESULTS

From October 2007 to April 2011, 116 women (mean age, 71.6 years) with operable infiltrating breast adenocarcinoma (T2-T4, N0-N3, M0) were randomized to receive anastrozole or fulvestrant. The clinical response rates at 6 months were 52.6% (95% confidence interval [CI], 41%-64%) in arm A and 36.8% (95% CI, 25%-49%) in arm B. BCS was performed for 57.6% of arm A patients and 50% of arm B patients. The RFS rates at 3 years were 94.9% in arm A and 91.2% in arm B. The Preoperative Endocrine Prognostic Index status was significantly predictive of RFS. Both treatments were well tolerated.

CONCLUSIONS

Both drugs are effective and well tolerated as NET in postmenopausal women with HR-positive/HER2-negative breast cancer. NET could be considered a treatment option in this subpopulation. Cancer 2016;122:3032-3040. © 2016 American Cancer Society.

Neoadjuvant endocrine therapy in breast cancer: current role and future perspectives

Luminal breast cancer, as defined by oestrogen and/or progesterone expression by immunohistochemistry, accounts for up to 75% of all breast cancers. In this population, endocrine therapy is likely to account for most of the gains obtained with the administration of adjuvant systemic treatment. The role of adjuvant chemotherapy in these patients remains debatable since it is known that only a small fraction of patients will derive meaningful benefit from this treatment whilst the majority will be exposed to significant and unnecessary chemotherapy-related toxicities, in particular the elderly and frail. Therefore, neoadjuvant endocrine therapy (NET) becomes an attractive option for selected patients with hormonal-receptor positive locally advanced breast cancer. In this review, we discuss the current role of NET and future perspectives in the field.

Approach and Management of Breast Cancer in the Elderly

Breast cancer is the mostly commonly diagnosed cancer in women both in the United States and worldwide. Although advanced age at diagnosis is associated with more favorable tumor biology, mortality rates are comparatively higher in older adults, possibly attributed to advanced stage at presentation. There are minimal specific treatment-based guidelines in elderly patients with cancer, mostly attributable to their limited inclusion on clinical trials. In addition to the existing evidence from clinical trials and retrospective studies, practitioners need to take into consideration functional status, social support, patient preference, presence of comorbidities, and life expectancy when selecting optimal treatment.

Clinical and genomic analysis of a randomised phase II study evaluating anastrozole and fulvestrant in postmenopausal patients treated for large operable or locally advanced hormone-receptor-positive breast cancer

BACKGROUND

The aim of this study was to assess the efficacy of neoadjuvant anastrozole and fulvestrant treatment of large operable or locally advanced hormone-receptor-positive breast cancer not eligible for initial breast-conserving surgery, and to identify genomic changes occurring after treatment.

METHODS

One hundred and twenty post-menopausal patients were randomised to receive 1 mg anastrozole (61 patients) or 500 mg fulvestrant (59 patients) for 6 months. Genomic DNA copy number profiles were generated for a subgroup of 20 patients before and after treatment.

RESULTS

A total of 108 patients were evaluable for efficacy and 118 for toxicity. The objective response rate determined by clinical palpation was 58.9% (95% CI=45.0-71.9) in the anastrozole arm and 53.8% (95% CI=39.5-67.8) in the fulvestrant arm. The breast-conserving surgery rate was 58.9% (95% CI=45.0-71.9) in the anastrozole arm and 50.0% (95% CI=35.8-64.2) in the fulvestrant arm. Pathological responses >50% occurred in 24 patients (42.9%) in the anastrozole arm and 13 (25.0%) in the fulvestrant arm. The Ki-67 score fell after treatment but there was no significant difference between the reduction in the two arms (anastrozole 16.7% (95% CI=13.3-21.0) before, 3.2% (95% CI=1.9-5.5) after, n=43; fulvestrant 17.1% (95%CI=13.1-22.5) before, 3.2% (95% CI=1.8-5.7) after, n=38) or between the reduction in Ki-67 in clinical responders and non-responders. Genomic analysis appeared to show a reduction of clonal diversity following treatment with selection of some clones with simpler copy number profiles.

CONCLUSIONS

Both anastrozole and fulvestrant were effective and well-tolerated, enabling breast-conserving surgery in over 50% of patients. Clonal changes consistent with clonal selection by the treatment were seen in a subgroup of patients.

Neoadjuvant endocrine therapy: Patient selection, treatment duration and surrogate endpoints

Neoadjuvant endocrine treatment has become of increasing interest for downstaging primary ER+ breast cancers as it has become clear that the pathologic complete response rate of luminal tumours to chemotherapy is much lower than that of non-luminal and differs little from that to endocrine therapy. There is much more experience in postmenopausal than premenopausal women. Aromatase inhibitors are generally the agent of choice. Responses are lower in those with the low levels of ER. While duration of endocrine treatment in clinical trials has usually been standardized at around three to four months it is clear that volume reductions continue to occur beyond that time in a large proportion of cases and routine clinical practice is often to treat to maximum response. This relatively slow emergence of downstaging relates to the absence of any increase in apoptosis with endocrine therapy and dependence of responses on the antiproliferative effects of oestrogen withdrawal: apoptosis occurs but at a slightly lower rate such that cell loss is attritional. The dependence of responses on the reduced proliferation underpins the value of Ki67 as an intermediate end-point for treatment benefit with multiple studies having found that relative effects on proliferation by different drugs in neoadjuvant trials match their relative impact on recurrence. While change in Ki67 is now accepted as a validated endpoint for comparing endocrine agents in the neoadjuvant scenario, on-treatment levels of Ki67 are related to long-term prognosis more closely than pretreatment Ki67. The Preoperative Endocrine Prognostic Index (PEPI) that combines residual Ki67 score with measures of on-treatment ER and other clinicopathologic factors has also found application in clinical trials. The potential to make longitudinal assessments of both clinical and biomarker responses has encouraged the development of novel clinical trial designs for assessing the impact of agents that aim to enhance response beyond that of endocrine agents alone. Such strategies include the early measurement of residual Ki67 levels after challenge with an endocrine agent alone and evaluation of the impact of the added agent on Ki67 or other agent-specific end-points.