The Magee 3 Equation Predicts Favorable Pathologic Response to Neoadjuvant Endocrine Therapy in Breast Cancer Patients

BACKGROUND

Breast cancer (BC) remains a significant health care challenge, and treatment approaches continue to evolve. Among these, neoadjuvant endocrine therapy (NET) has gained prominence, particularly for postmenopausal, hormone-receptor positive, HER2-negative (HR+/HER2-) BC patients. Despite this, a significant gap exists in identifying patients who stand to benefit from NET. The objective of this study was to assess whether Magee equations (MEs) could serve as predictors of response to NET.

METHODS

This retrospective study included adult patients with invasive BC who underwent NET followed by curative surgery. Assessment of sociodemographic, clinical, and tumor-related variables was conducted. The ME1, ME2, ME3, and ME mean were analyzed to explore their predictive role for NET response. Receiver operating characteristic (ROC) curves were employed, along with the determination of optimal cutoff points. Logistic regression models were utilized to identify the most significant predictors of pathological response.

RESULTS

Among the 75 female participants, the mean age was 69.4 years, with the majority being postmenopausal (n = 72, 96%) and having an ECOG-PS of 0/1 (n = 63, 84%). Most patients were classified as luminal A (n = 41, 54.7%). ME3 emerged as a promising predictor, boasting an AUC of 0.734, with sensitivity of 90.62% and specificity of 57.50% when the threshold was ≤ 19.97. In univariate analysis, clinical staging (p = 0.002), molecular subtype (p = 0.001), and ME3 (continuous = 0.001, original 3-tier: p = 0.013, new 2-tier: <0.001) categories exhibited significant associations with pathological response. In the multivariate model, clinical staging and new 2-tier ME3 (<20 vs. ≥20) were included as significant variables.

CONCLUSIONS

Patients with ME3 < 20 have a higher likelihood of presenting a pathological response, offering a cost-effective alternative tool to Oncotype DX. Larger future studies with a prospective design are awaited to confirm our findings.

Neoadjuvant chemotherapy combined with endocrine therapy for hormone receptor-positive breast cancer: A systematic review and meta-analysis

BACKGROUND

This study aimed to conduct a comparative analysis of the efficacy and safety of neoadjuvant chemotherapy combined with endocrine therapy against the backdrop of single neoadjuvant chemotherapy or endocrine therapy, specifically in the context of hormone receptor-positive (HR+) breast cancer treatment.

METHODS

We conducted a thorough literature search across several databases, including China National Knowledge Infrastructure, Wanfang, Weipu, Chinese Journal Full-text Database, PubMed, Web of Science, Cochrane Library, and EMBASE, adhering to the guidelines outlined in the PRISMA statement. Our specific focus was on identifying randomized controlled trials that directly compared the combined approach of neoadjuvant chemotherapy and endocrine therapy with single chemotherapy or endocrine therapy in the context of treating HR+ breast cancer. Subsequently, we utilized statistical packages implemented in R software to perform comparative analyses of key clinical indicators, encompassing the complete response, objective response rate (ORR), disease control rate, pathological complete response (pCR), and adverse reactions.

RESULTS

A total of 11 randomized controlled trials, involving 1359 patients, all of whom met our inclusion criteria and were thus included in our comprehensive analysis. Within this cohort, 688 patients (50.63%) administered neoadjuvant chemotherapy combined with endocrine therapy (NCET), 642 patients (47.24%) received neoadjuvant chemotherapy (NCT) alone, while 29 patients (2.13%) underwent neoadjuvant endocrine therapy (NET) alone. The results of our meta-analysis revealed that NCET exhibited a statistically significant enhancement in both ORR and pCR (P < .05). Nonetheless, when compared to NCT or NET, NCET did not yield a significant impact on complete response, disease control rate, and safety (P > .05). In addition, NCET demonstrated a significant improvement in ORR among patients with HR+, HER2-negative breast cancer (P < .05). However, it was also linked to a heightened incidence of serious adverse reactions within this particular patient subgroup (P < .05).

CONCLUSION

The combination of Neoadjuvant chemotherapy and endocrine therapy stands out as a significant contributor to enhancing the ORR and pCR for HR+ breast cancer patients. For breast cancer patients with HER2- status, NCET demonstrates a remarkable improvement in ORR but is also associated with the emergence of adverse reactions.

Use of Ultrasound and Ki-67 Proliferation Index to Predict Breast Cancer Tumor Response to Neoadjuvant Endocrine Therapy

BACKGROUND

Prediction of tumor shrinkage and pattern of treatment response following neoadjuvant endocrine therapy (NET) for estrogen receptor positive (ER+), Her2 negative (Her2-) breast cancers have had limited assessment. We examined if ultrasound (US) and Ki-67 could predict the pathologic response to treatment with NET and how the pattern of response may impact surgical planning.

METHODS

A total of 103 postmenopausal women with ER+, HER2- breast cancer enrolled on the FELINE trial had Ki-67 obtained at baseline, day 14, and surgical pathology. A total of 70 patients had an US at baseline and at the end of treatment (EOT). A total of 48 patients had residual tumor bed cellularity (RTBC) assessed. The US response was defined as complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). CR or PR on imaging and ≤70% residual tumor bed cellularity (RTBC) defined a contracted response pattern.

RESULTS

A decrease in Ki-67 at day 14 was not predictive of EOT US response or RTBC. A contracted response pattern was identified in one patient with CR and in sixteen patients (33%) with PR on US. Although 26 patients (54%) had SD on imaging, 22 (85%) had RTBC ≤70%, suggesting a non-contracted response pattern of the tumor bed. The remaining four (15%) with SD and five with PD had no response.

CONCLUSION

Ki-67 does not predict a change in tumor size or RTBC. NET does not uniformly result in a contracted response pattern of the tumor bed. Caution should be taken when using NET for the purpose of downstaging tumor size or converting borderline mastectomy/lumpectomy patients.

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.

EZH2 Protein Expression in Estrogen Receptor Positive Invasive Breast Cancer Treated With Neoadjuvant Endocrine Therapy: An Exploratory Study of Association With Tumor Response

INTRODUCTION

Neoadjuvant endocrine therapy (NET) can be used to treat estrogen receptor positive (ER+) invasive breast cancer (IBC). Tumors with Ki67>10% after 2 to 4 weeks of NET are considered resistant to endocrine therapy. Enhancer of Zeste Homolog 2 (EZH2) is a targetable oncoprotein and overexpression in ER+ IBC has been linked to resistance to endocrine therapy. We examined whether EZH2 expression levels in ER+ IBC could be used to predict response to NET.

MATERIALS AND METHODS

We retrospectively identified 46 patients with localized ER+ HER2/neu negative IBC treated with a minimum of 4 weeks of NET. We quantified EZH2 nuclear expression in pretherapy core biopsies using a score that included intensity and percent of cells staining. Ki67 was evaluated in both pretherapy core biopsies and posttherapy tumor resections and scored according to the guidelines of the International Ki67 Working Groups, with a global weighted score. Ki67≤10% after NET was considered endocrine responsive. Logistic regression analysis was performed to determine the association between EZH2 expression and response to NET.

RESULTS

We found significant associations of tumor grade ( P =0.011), pretherapy Ki67 ( P =0.003), and EZH2 ( P <0.001), with response to NET. On logistic regression adjusted for tumor grade and pretherapy Ki67, increased EZH2 scores were associated with decreased odds of endocrine responsiveness, defined as posttreatment Ki67≤10% (odds ratio=0.976, 95% CI, 0.956 to 0.997; P =0.026). In addition, with EZH2 score in the model, associations of tumor grade and pretreatment Ki67 with posttreatment Ki67≤10% response to NET became not significant.

CONCLUSIONS

Our results suggest that EZH2 might be a useful biomarker to predict response to NET.

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

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

Bridging Endocrine Therapy for HR+/HER2- Resectable Breast Cancer: Is it Safe?

BACKGROUND

The COVID-19 pandemic has required new treatment paradigms to limit exposures and optimize hospital resources, including the use of neoadjuvant endocrine therapy (NAET) as bridging therapy for HR+/HER2-invasive tumors and DCIS. While this approach has been used in locally advanced disease, it is unclear how it may affect outcomes in resectable HR+/HER2- tumors.

METHODS

Women ≥18 years diagnosed with in situ (Tis) or non-metastatic HR+/HER2- breast cancer from March-May 2019 and 2020 were included. Fisher's exact test and two-sample t test were used to compare baseline characteristics and surgical outcomes between strata. Sub-analysis was performed between patients who received primary surgery vs a bridging NAET approach.

RESULTS

Despite similar clinical characteristics, patients in 2019 were more likely to have a surgery-first approach (75% vs 42%, P-value = .0007), receive surgery sooner (22 vs 29 days, P-value < .001), and within 60 days from diagnosis date (100% vs 85%, P-value = .0301). Neoadjuvant endocrine therapy was a more prevalent approach in 2020 (48% vs 7%, P-value < .0001). Rates of clinical to pathologic up-staging remained consistent across primary surgery vs bridging NAET subgroups (P-value = .9253).

DISCUSSION

Pandemic-driven treatment protocols provide a unique opportunity to assess the utility of bridging endocrine therapy for resectable HR+/HER2- tumors. Differences in clinical and pathologic staging were similar across groups and did not appear to be affected by receipt of NAET. Our limited cohort demonstrates this strategic therapeutic avenue can optimize health care utilization and may be a reasonable approach when delaying surgery is preferred.

Patient-Reported Outcomes From Phase III Neoadjuvant Systemic Trial Comparing Neoadjuvant Chemotherapy With Neoadjuvant Endocrine Therapy in Pre-Menopausal Patients With Estrogen Receptor-Positive and HER2-Negative, Lymph Node-Positive Breast Cancer

We aimed to evaluate the patient-reported outcomes (PROs) in a prospective phase III clinical trial, comparing neoadjuvant endocrine therapy (NET) with conventional neoadjuvant chemotherapy (NCT) in patients with hormone status positive, lymph node-positive premenopausal breast cancer (NCT01622361). The patients were randomized prospectively to either 24 weeks of NCT with adriamycin plus cyclophosphamide followed by taxane or NET with gonadotropin-releasing hormone agonist and tamoxifen. The patients were examined at the surgery unit of a large tertiary care hospital with a comprehensive cancer center. PROs were assessed on the first day of the trial (day 1, baseline) and at the end of treatment, using the breast cancer module of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 23 (EORTC QLQ BR23). One hundred and eighty-seven patients were randomly assigned to chemotherapy (n=95) or endocrine therapy (n=92), and 174 patients completed 24 weeks of the neoadjuvant treatment period (n=87, in each group). Baseline scores were similar between the groups. After treatment, there were no statistically significant differences in the function scales, including body image, sexual functioning, and sexual enjoyment between the groups, although the endocrine treatment group showed a significant improvement in the future perspective (hazard ratio, 8.3; 95% confidence interval, 1.72-18.38; P = 0.021). Similarly, there were no statistically significant differences in the symptom scales between the groups, including adverse effects of systemic therapy, breast symptoms, arm symptoms, and upset about hair loss. In conclusion, overall PROs were similar in both treatment groups, except for "future perspective," which was significantly better in the NET group than in the NCT group.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.Gov, identifier NCT01622361.

Approaching Neoadjuvant Therapy in the Management of Early-Stage Breast Cancer

Neoadjuvant therapy is integral to the treatment of early-stage breast cancer. Goals of treatment include surgical downstaging of the tumor, rendering inoperable tumors resectable, and de-escalating axillary surgery in those with clinically positive nodes. Additionally, response to treatment provides important prognostic information regarding risk of recurrence and guides future adjuvant treatment. Although chemotherapy serves as the backbone of neoadjuvant treatment, an increased understanding of the tumor's clinical course as well as its molecular and genetic make-up aids in individualizing treatment and developing novel agents. This review summarizes current clinical approaches and the future direction to the management of breast cancer patients in the neoadjuvant setting.

The Role of Ki67 in Evaluating Neoadjuvant Endocrine Therapy of Hormone Receptor-Positive Breast Cancer

Ki67 is a proliferation marker. It has been proposed as a useful clinical marker for breast cancer subtype classification, prognosis, and prediction of therapeutic response. But the questionable analytical validity of Ki67 prevents its widespread adoption of these measures for treatment decisions in breast cancer. Currently, Ki67 has been tested as a predictive marker for chemotherapy using clinical and pathological response as endpoints in neoadjuvant endocrine therapy. Ki67 can be used as a predictor to evaluate the recurrence-free survival rate of patients, or its change can be used to predict the preoperative "window of opportunity" in neoadjuvant endocrine therapy. In this review, we will elaborate on the role of Ki67 in neoadjuvant endocrine therapy in breast cancer.

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.

Efficacy of neoadjuvant endocrine therapy in patients with poorly differentiated neuroendocrine carcinoma of the breast: A case report

RATIONALE

Poorly differentiated neuroendocrine carcinoma of the breast is a rare cancer with poor prognosis. There is no standard treatment for the disease. Neoadjuvant therapies and surgery are considered to be the main treatment when the tumor diameter is greater than 5.0 cm. Neoadjuvant therapies include chemotherapy and endocrine therapy. However, the effect of neoadjuvant endocrine therapy is not clear in the disease.

PATIENT CONCERNS

In August 2014, a 28-year-old premenopausal woman noted a mass that was approximately 3.0 cm*2.0 cm in size on her right breast with pain. Subsequently, the mass has been always increasing significantly. In August 2015, the mass was approximately 7.0 cm*5.0 cm in size, accompanied by pain, no nipple retraction and discharge, no orange peel-like skin changes, and no dimples. In addition, she had no salient past history.

DIAGNOSES

Histopathological examinations by a biopsy with a thick needle (hollow needle) and surgical resection confirmed poorly differentiated neuroendocrine carcinoma of the right breast.

INTERVENTIONS

First and remarkably, she underwent 3 months of neoadjuvant endocrine therapy (goserelin once every 28 days, and letrozole 10 mg every day). Then, she underwent surgery - stage I breast reconstruction by using prosthesis. Adjuvant endocrine therapy has been used since the operation.

OUTCOMES

According to response evaluation criteria in solid tumors 1.1, the tumor was shrunk by 78.87% after neoadjuvant endocrine therapy. No salient complications were observed. We have followed her for 48 months, and there are no signs of recurrence and metastasis.

LESSONS

Poorly differentiated neuroendocrine carcinoma of the breast is rare and has a poor prognosis. Currently, there is no standard treatment for this disease. Studies show estrogen receptor and progesterone receptor of neuroendocrine carcinoma of the breast are often highly expressed. In the case, it can be observed that estrogen receptor and progesterone receptor are highly expressed. Therefore, neoadjuvant endocrine therapy may be considered in neuroendocrine carcinoma of the breast when the mass is large and the patient refuses neoadjuvant chemotherapy. We hope to provide an attractive evidence for neoadjuvant endocrine therapy of neuroendocrine carcinoma of the breast. However, more cases are still being needed for research.

Strategies for Increasing the Effectiveness of Aromatase Inhibitors in Locally Advanced Breast Cancer: An Evidence-Based Review on Current Options

Neoadjuvant hormonal therapy (NEO-HT) is a possible treatment option for breast cancer (BC) patient with estrogen receptor positive (ER+) and HER2 negative (HER2-) disease. The absence of solid data on the type of drugs to be used and duration of treatment as well as lack of clear evidence of effectiveness of NEO-HT compared to chemotherapy (CT) reserve its use for patients with old age or frail conditions. However, the low pathologic complete response rate (pCR) obtained with tamoxifen or aromatase inhibitors (AIs) alone does not make NEO-HT as a suitable option for the neoadjuvant treatment of HR+ HER2-. The use of the cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitors palbociclib, ribociclib and abemaciclib of the mammalian target of rapamycin (mTOR) inhibitor everolimus and of the phosphoinositide 3 kinase (PI3K) inhibitor taselisib together with endocrine therapy (ET) has become a standard in advanced breast cancer, showing clinical effectiveness and significantly prolonging median progression-free survival compared to ET only. In the early phase disease, the use of ET together with CDK 4/6, mTOR and PI3K inhibitors is still investigational. Data from recent studies are promising even though less impressive than in metastatic setting. In this context, the use of genomic-transcriptomic tools (such as ONCOTYPE, PAM50) and the identification of novel biomarkers (ESR1, PI3Kca, PDGF-R) on tissue or with liquid biopsy could help to select patient prone to respond to endocrine-combined therapy and able to achieve pCR. With our review, we aimed at evaluating the current state of the art in the treatment of locally advanced breast cancer with NEO-HT.

Efficacy and acceptability of neoadjuvant endocrine therapy in patients with hormone receptor-positive breast cancer: A network meta-analysis

BACKGROUND

The optimal sequence of endocrine therapy in a neoadjuvant setting for hormone receptor-positive (HR+) breast cancer is unclear. Our study evaluated the efficacy and acceptability of neoadjuvant endocrine therapy for HR+ breast cancer.

METHODS

We identified studies based on titles and abstracts that were published before 22 June 2018 in the following databases: PubMed, EMBASE, and the Cochrane Library. Eligible studies were randomised controlled trials with at least one arm that evaluated the effectiveness of one or a combination of anastrozole, letrozole, palbociclib, tamoxifen, fulvestrant, abemaciclib, everolimus, gefitinib, ribociclib, taselisib, and exemestane. We pooled effect sizes using the odds ratio (OR) and corresponding 95% credibility interval (95% CrI). The primary outcomes were response rate and treatment completion.

RESULTS

Our network meta-analysis included 3,306 participants and 16 eligible studies, which assessed 15 treatments. In terms of response rates, compared with letrozole combined therapy, tamoxifen was associated with a significant reduction in response rate (OR, 0.34; 95% CrI, 0.13-0.85; OR, 0.32; 95% CrI, 0.13-0.80; OR, 0.26; 95% CrI, 0.09-0.83; and OR, 0.30; 95% CrI, 0.09-0.96; for letrozole plus everolimus, letrozole plus taselisib, letrozole plus zoledronic acid, and letrozole plus lapatinib, respectively). Based on the surface under the cumulative ranking curves ranking, letrozole plus zoledronic acid was associated with the highest rate of response (87.6%), followed by letrozole plus lapatinib (85.2%), and letrozole plus taselisib (79.3%).

CONCLUSIONS

Ultimately, our study established that letrozole plus zoledronic acid may be an optimal treatment based on its current rank in a neoadjuvant setting for HR+ breast cancer.

Impact of clinical response to neoadjuvant endocrine therapy on patient outcomes: a follow-up study of JFMC34-0601 multicentre prospective neoadjuvant endocrine trial

Background

Neoadjuvant endocrine therapy (NET) has been demonstrated to improve breast-conserving rate and is a widely accepted treatment option for postmenopausal patients with hormone receptor-positive breast cancer. There are few reports on the association of NET response and long-term outcomes.

Objectives

To investigate the prognostic value of clinical response to NET.

Methods

Long-term outcomes of NET were examined in 107 patients who participated in the multicentre prospective neoadjuvant exemestane study, JFMC34-0601. Patients were treated with 25 mg/day exemestane for 16 weeks followed by an 8-week extension depending on the treatment response.

Results

Clinical response included partial response (PR) in 58 patients, stable disease in 41 patients and progressive disease (PD) in 8 patients. Clinical response was significantly associated with disease-free survival (DFS), distant disease-free survival (DDFS) and overall survival (OS) (P<0.0001 for all). Especially, patients with PD showed markedly poor outcomes with median DFS=17.8 months (HR (vs PR): 7.7 (95% CI 1.6 to 33)) and median OS=37.7 months (HR (vs PR): 26.3 (95% CI 2.4 to 655)). Preoperative endocrine prognostic index (PEPI) were associated with DFS and marginally with OS (P=0.022 and 0.066, respectively). PEPI=0 indicated an excellent prognosis with 95% 5-year DFS (95% CI 73 to 99). In the multivariate analysis including T stage, nodal status and Ki67, clinical response was an independent prognostic factor for DFS, DDFS and OS (P=0.032, 0.0007 and 0.020, respectively), whereas PEPI was marginally associated with DFS and OS (P=0.079 and 0.068, respectively).

Conclusions

Clinical response to NET showed an independent prognostic value. Patients with PD had markedly poor prognosis, indicating a need of additional therapy. PEPI=0 indicated an excellent prognosis. The integration of clinical response and PEPI would improve decision-making with regard to treatment options for endocrine-responsive breast cancer when these results are validated in a larger clinical trial.

Trial registration number

UMIN C000000345.

Activation of PI3K/Akt/mTOR signaling in the tumor stroma drives endocrine therapy-dependent breast tumor regression

Improved efficacy of neoadjuvant endocrine-targeting therapies in luminal breast carcinomas could be achieved with optimal use of pathway targeting agents. In a mouse model of ductal breast carcinoma we identify a tumor regressive stromal reaction that is induced by neoadjuvant endocrine therapy. This reparative reaction is characterized by tumor neovascularization accompanied by infiltration of immune cells and carcinoma-associated fibroblasts that stain for phosphorylated ribosomal protein S6 (pS6), downstream the PI3K/Akt/mTOR pathway. While tumor variants with higher PI3K/Akt/mTOR activity respond well to a combination of endocrine and PI3K/Akt/mTOR inhibitors, tumor variants with lower PI3K/Akt/mTOR activity respond more poorly to the combination therapy than to the endocrine therapy alone, associated with inhibition of stromal pS6 and the reparative reaction. In human breast cancer xenografts we confirm that such differential sensitivity to therapy is primarily determined by the level of PI3K/Akt/mTOR in tumor cells. We further show that the clinical response of breast cancer patients undergoing neoadjuvant endocrine therapy is associated with the reparative stromal reaction. We conclude that tumor level and localization of pS6 are associated with therapeutic response in breast cancer and represent biomarkers to distinguish which tumors will benefit from the incorporation of PI3K/Akt/mTOR inhibitors with neoadjuvant endocrine therapy.

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.

Effect of targeted agents on the endocrine response of breast cancer in the neoadjuvant setting: a systematic review

Inhibition of aberrantly activated pathways cross-talking with hormone receptor (HR) improves response to endocrine therapy in patients with HR-positive advanced breast cancer. We performed a Pubmed database systematic review to ascertain the existence of a better clinical response when combining endocrine therapy with targeted agents in the neoadjuvant setting. Preclinical studies or trials evaluating toxicity were excluded.

We found nine phase II trials that fulfilled the research criteria. The endocrine agents used were third generation aromatase inhibitors (AIs), anastrozole, letrozole or exemestane. The investigated targeted agents were inhibitors of tyrosine kinase receptors such as gefitinib, imatinib or trastuzumab/lapatinib, inhibitors of mTOR, such as everolimus, inhibitors of COX-2, such as celecoxib, and inhibitors of angiogenesis, such as bevacizumab. The response rate (RR) observed combining endocrine and targeted agents ranged between 36% and 90%.

Overall the studies failed to show a remarkable advantage in RR in the combination group compared to historical control subjects receiving AIs alone.

A Canadian national expert consensus on neoadjuvant therapy for breast cancer: linking practice to evidence and beyond

BACKGROUND

Use of the neoadjuvant approach to treat breast cancer patients has increased since the early 2000s, but the overall pathway of care for such patients can be highly variable. The aim of our project was to establish a multidisciplinary consensus among clinicians with expertise in neoadjuvant therapy (nat) for breast cancer and to determine if that consensus reflects published methods used in randomized controlled trials (rcts) in this area.

METHODS

A modified Delphi protocol, which used iterative surveys administered to 85 experts across Canada, was established to obtain expert consensus concerning all aspects of the care pathway for patients undergoing nat for breast cancer. All rcts published between January 1, 1967, and December 1, 2012, were systematically reviewed. Data extracted from the rcts were analyzed to determine if the methods used matched the expert consensus for specific areas of nat management. A scoring system determined the strength of the agreement between the literature and the expert consensus.

RESULTS

Consensus was achieved for all areas of the pathway of care for patients undergoing nat for breast cancer, with the exception of the role of magnetic resonance imaging in the pre-treatment or preoperative setting. The levels of agreement between the consensus statements and the published rcts varied, primarily because specific aspects of the pathway of care were not well described in the reviewed literature.

CONCLUSIONS

A true consensus of expert opinion concerning the pathway of care appropriate for patients receiving nat for breast cancer has been achieved. A review of the literature illuminated gaps in the evidence about some elements of nat management. Where evidence is available, agreement with expert opinion is strong overall. Our study is unique in its approach to establishing consensus among medical experts in this field and has established a pathway of care that can be applied in practice for patients receiving nat.

Neoadjuvant therapy for breast cancer

Neoadjuvant treatment of breast cancer refers to the use of different treatment modalities prior to surgical excision of the tumor. It has been accepted as a treatment option for patients with nonmetastatic disease, because it renders inoperable tumors operable and increases the rates of breast-conserving surgery, while achieving similar long-term clinical outcomes as adjuvant treatment. The neoadjuvant setting is being increasingly perceived as a research platform, where the biologic effects of traditional anticancer agents can be delineated, prognostic and predictive biomarkers can be identified, and the development of targeted agents can be expedited. Surrogate endpoints that can predict long-term clinical outcome and are evaluable early on, such as the pathologic complete response, offer valuable opportunities for rapid assessment of anticancer agents. Additionally, efforts for molecular profiling of the post-neoadjuvant residual disease hold the potential to lead to personalized therapy for breast cancer patients with early-stage high-risk disease.

Neoadjuvant endocrine therapy in primary breast cancer: indications and use as a research tool

Neoadjuvant endocrine therapy has been increasingly employed in clinical practice to improve surgical options for postmenopausal women with bulky hormone receptor-positive breast cancer. Recent studies indicate that tumour response in this setting may predict long-term outcome of patients on adjuvant endocrine therapy, which argues for its broader application in treating hormone receptor-positive disease. From the research perspective, neoadjuvant endocrine therapy provides a unique opportunity for studies of endocrine responsiveness and the development of novel therapeutic agents.