Aerobic exercise and CogniTIVe functioning in women with breAsT cancEr (ACTIVATE): A randomized controlled trial.

BACKGROUND: As the prevalence of chemotherapy-related cognitive impairment rises, investigation into treatment options is critical. The objectives of this study were to test the effects of an aerobic exercise intervention initiated during chemotherapy compared to usual care (wait list control condition) on (1) objectively measured cognitive function and self-reported cognitive function, as well as on (2) the impact of cognitive impairment on quality of life (QOL) postintervention (commensurate with chemotherapy completion). METHODS: The Aerobic exercise and CogniTIVe functioning in women with breAsT cancEr (ACTIVATE) trial was a two-arm, two-center randomized controlled trial conducted in Ottawa and Vancouver (Canada). Fifty-seven women (Mage, 48.8 ± 10 years) diagnosed with stage I-III breast cancer and awaiting chemotherapy were randomized to aerobic exercise initiated with chemotherapy (nEX = 28) or usual care during chemotherapy with aerobic exercise after chemotherapy completion (nUC = 29). The intervention lasted 12-24 weeks and consisted of supervised aerobic training and at-home exercise. The primary outcome was objective cognitive function measured via 13 neuropsychological tests (standardized to M ± SD, 0 ± 1); secondary outcomes of self-reported cognitive function and its impact on QOL were assessed via questionnaires. Data collected pre- and postintervention (the primary end point) were analyzed. RESULTS: Although no significant differences between groups were found for objective cognitive function outcomes postintervention after accounting for multiple testing, four of six self-reported cognitive function outcomes showed significant differences favoring the aerobic exercise group. CONCLUSIONS: Among women initiating chemotherapy for breast cancer, aerobic exercise did not result in significant differences in objective cognitive function postintervention after chemotherapy completion; however, the results do support the use of this intervention for improving self-reported cognitive function and its impact on QOL.

Breast Arterial Calcifications on Mammography: Awareness and Reporting Preferences Amongst Referring Physicians in Canada.

Purpose: Breast arterial calcifications (BAC) on mammography have been correlated with increased cardiovascular risk. The Canadian Society of Breast Imaging released a position statement on BAC reporting in January 2023. This study evaluates the awareness of the clinical significance of BAC and reporting preferences of referring physicians in Canada. Methods: A 15-question survey was distributed to Canadian physicians who may review mammography results via regional and subspecialty associations and on social media following local institutional ethical approval. Responses were collected over 10 weeks from February to April 2023. Results: Seventy-two complete responses were obtained. We are unable to determine the response rate, given the means of distribution. Only 17% (12/72) of responding physicians were previously aware of the association between BAC and increased cardiovascular risk, and 51% (37/72) preferred the inclusion of BAC in the mammography report. Fifty-six percent (40/72) indicated that BAC reporting would prompt further investigation, and 63% (45/72) would inform patients that their mammogram showed evidence of BAC. Sixty-nine percent (50/72) would find grading of BAC beneficial and 71% (51/72) agreed that there is a need for national guidelines. Conclusion: Less than a quarter of responding Canadian referring physicians were previously aware of the association between BAC and cardiovascular risk, although half of respondents indicated a preference for BAC reporting on mammography. Most participating physicians would inform their patients of the presence of BAC and consider further cardiovascular risk management. There was consensus that a national BAC grading system and clinical management guidelines would be beneficial.

Type and timing of systemic therapy use predict overall survival for patients with brain metastases treated with radiation therapy.

INTRODUCTION: This study aimed to investigate whether systemic therapy (ST) use surrounding radiation therapy (RT) predicts overall survival (OS) after RT for patients with brain metastases (BMs). METHODS: Provincial RT and pharmacy databases were used to review all adult patients in British Columbia, Canada, who received a first course of RT for BMs between 2012 and 2016 (n = 3095). Multivariate analysis on a randomly selected subset was used to develop an OS nomogram. RESULTS: In comparison to the 2096 non-recipients of ST after RT, the median OS of the 999 recipients of ST after RT was 5.0 (95% Confidence interval (CI) 4.1-6.0) months longer (p < 0.0001). Some types of ST after RT were independently predictive of OS: targeted therapy (hazard ratio (HR) 0.42, CI 0.37-0.48), hormone therapy (HR 0.45, CI 0.36-0.55), cytotoxic chemotherapy (HR 0.71, CI 0.64-0.79), and immunotherapy (HR 0.64, CI 0.37-1.06). Patients who discontinued ST after RT had 0.9 (CI 0.3-1.4) months shorter median OS than patients who received no ST before or after RT (p < 0.0001). In the multivariate analysis of the 220-patient subset, established prognostic variables (extracranial disease, performance status, age, cancer diagnosis, and number of BMs), and the novel variables "ST before RT" and "Type of ST after RT" independently predicted OS. The nomogram predicted 6- and 12-month OS probability and median OS (bootstrap-corrected Harrell's Concordance Index = 0.70). CONCLUSIONS: The type and timing of ST use surrounding RT predict OS for patients with BMs.

Effects of High Anxiety Scores on Surgical and Overall Treatment Plan in Patients with Breast Cancer Treated with Neoadjuvant Therapy.

BACKGROUND: Patients with newly diagnosed breast cancer and high levels of anxiety often pursue more aggressive surgical interventions. The neoadjuvant treatment (NAT) setting could provide a window of opportunity to address patients' anxiety. However, the impact of anxiety on surgical decisions in the setting of NAT for breast cancer has not been previously studied. MATERIALS AND METHODS: A prospective database of patients with breast cancer treated with NAT at BC Cancer was used to identify patients treated with NAT and subsequent surgical resection. Patients with bilateral breast cancer or BRCA mutations or those referred to the hereditary cancer program were excluded. An anxiety score of 0-3 was assigned based on responses to the Edmonton Symptom Assessment System and Psychosocial Screen for Cancer. Clinicopathological information and treatment data were retrieved and cross-referenced between the low-anxiety (scores 0-1) and high-anxiety (scores 2-3) cohorts. RESULTS: From 2012 to 2016, 203 patients met eligibility criteria. Of these, 93 patients (45.8%) had low anxiety and 110 patients (54.2%) had high anxiety. Overall, 161 patients (79.3%) had locally advanced cancers; no differences in stage, grade, or biomarkers were found between the low- and high-anxiety cohorts. Patients with high self-reported anxiety at initial consultation were younger (mean 56 years vs. 60 years; p = .011) and more likely to undergo mastectomy for breast-conserving surgery-eligible disease and bilateral mastectomy for unilateral disease compared with those with low anxiety (37.3% vs. 18.3%; likelihood ratio 9.15; p = .002). No significant differences in treatment timelines were identified between the two cohorts. CONCLUSION: Patients with high anxiety at initial consultation were nine times more likely to undergo aggressive surgery compared with patients with low anxiety. These findings underscore the need for early identification of patients who may benefit from tailored supportive and educational services to address sources of anxiety and knowledge gaps. IMPLICATIONS FOR PRACTICE: The prevalence of anxiety among women with newly diagnosed breast cancer is being increasingly acknowledged. However, health care providers have not fully appreciated the impact of anxiety on the surgical management of patients with early-stage breast cancer. This study highlights the importance of self-reported anxiety on surgical management. The preoperative period provides a unique window of opportunity to address sources of anxiety and provide targeted educational materials over a period of 4-6 months, which may ultimately lead to less aggressive surgery when it is not needed.

Study protocol of the Aerobic exercise and CogniTIVe functioning in women with breAsT cancEr (ACTIVATE) trial: a two-arm, two-centre randomized controlled trial.

BACKGROUND: Up to 75% of women diagnosed with breast cancer report chemotherapy-related cognitive changes (CRCC) during treatment, including decreased memory, attention, and processing speed. Though CRCC negatively impacts everyday functioning and reduces overall quality of life in women diagnosed with breast cancer, effective interventions to prevent and/or manage CRCC are elusive. Consequently, women seldom receive advice on how to prevent or manage CRCC. Aerobic exercise is associated with improved cognitive functioning in healthy older adults and adults with cognitive impairments. Accordingly, it holds promise as an intervention to prevent and/or manage CRCC. However, evidence from randomized controlled trials (RCTs) supporting a beneficial effect of aerobic exercise on CRCC is limited. The primary aim of the ACTIVATE trial is to evaluate the impact of supervised aerobic exercise on CRCC in women receiving chemotherapy for breast cancer. METHODS: The ACTIVATE trial is a two-arm, two-centre RCT. Women diagnosed with stage I-III breast cancer and awaiting neo-adjuvant or adjuvant chemotherapy are recruited from hospitals in Ottawa (Ontario) and Vancouver (British Columbia), Canada. Recruits are randomized to the intervention group (aerobic exercise during chemotherapy) or the wait-list control group (usual care during chemotherapy and aerobic exercise post-chemotherapy). The primary outcome is cognitive functioning as measured by a composite cognitive summary score (COGSUM) of several neuropsychological tests. Secondary outcomes are self-reported cognitive functioning, quality of life, and brain structure and functioning (measured by magnetic resonance imaging (MRI)/functional MRI and electroencephalography). Assessments take place pre-chemotherapy (pre-intervention), mid-way through chemotherapy (mid-intervention/mid-wait period), end of chemotherapy (post-intervention/post-wait period; primary endpoint), 16-weeks post-chemotherapy, and at 1-year post-baseline. DISCUSSION: Aerobic exercise is a promising intervention for preventing and/or managing CRCC and enhancing quality of life among women diagnosed with breast cancer. The ACTIVATE trial tests several novel hypotheses, including that aerobic exercise can prevent and/or mitigate CRCC and that this effect is mediated by the timing of intervention delivery (i.e., during versus post-chemotherapy). Findings may support prescribing exercise during (or post-) chemotherapy for breast cancer and elucidate the potential role of aerobic exercise as a management strategy for CRCC in women with early-stage breast cancer. TRIAL REGISTRATION: The trial was registered with the ClinicalTrials.gov database ( NCT03277898 ) on September 11, 2017.

Cancer screening and prevention in BRCA mutation carriers: a missed opportunity?

While the elevated lifetime risk of breast and ovarian cancer is well recognised for patients with a BRCA mutation, the implementation of effective risk reduction strategies has been fraught with challenges. This report from an international database and published in the British Journal of Cancer reveals suboptimal rates of utilisation of surveillance/preventative measures globally.

Optimal vascular access strategies for patients receiving chemotherapy for early-stage breast cancer: a systematic review.

IMPORTANCE: Systemic chemotherapy can be administered either through a peripheral vein (IV), or centrally through peripherally inserted central catheter (PICC), totally implanted vascular access devices (PORTs) or tunnelled cuffed catheters. Despite the widespread use of systemic chemotherapy in patients with breast cancer, the optimal choice of vascular access is unknown. OBJECTIVE: This systematic review evaluated complication rates and patient satisfaction with different access strategies for administering neo/adjuvant chemotherapy for breast cancer. EVIDENCE REVIEWED: Ovid Medline, EMBASE and the Cochrane Central Register of Controlled Trials were searched from 1946 to September 2017. Two reviewers independently assessed each citation. The Newcastle-Ottawa scale was used to assess the quality of cohort and case-control studies. FINDINGS: Of 1584 citations identified, 15 unique studies met the pre-specified eligibility criteria. There were no randomised studies comparing types of vascular access. Reports included six single-institution retrospective cohort studies, one retrospective multi-institution cohort, one retrospective cohort database study, five prospective single-institution studies, one prospective multi-institution study and one nested case-control study. Median complication rates were infection: 6.0% PICC (2 studies) versus 2.1% PORT (8 studies); thrombosis: 8.9% PICC (2 studies) versus 2.6% PORT (9 studies); extravasation: 0 PICC (1 study) versus 0.4% PORT (4 studies) and mechanical issues: PICC 3.8% (1 study) versus 1.8% PORT (9 studies). Satisfaction/quality of life appeared high with each device. CONCLUSION: In the absence of high-quality data comparing vascular access strategies, randomised, adequately powered, prospective studies would be required to help inform clinical practice and reduce variation.

An Overview of Long-Acting GnRH Agonists in Premenopausal Breast Cancer Patients: Survivorship Challenges and Management.

Managing breast cancer in premenopausal women poses unique challenges due to its considerable effect on both morbidity and mortality. Goserelin, a gonadotropin-releasing hormone agonist, has emerged among the various modalities as a preferred option for ovarian function suppression, owing to its efficacy in reducing ovarian estrogen production in premenopausal women with hormone receptor-positive breast cancer. Recent studies have affirmed the efficacy and safety of long-acting (LA) goserelin 10.8 mg every 12 weeks, offering comparable outcomes to monthly injections. This flexibility enables personalized treatment approaches, potentially enhancing patient satisfaction. Off-label utilization of goserelin LA surged during the coronavirus disease pandemic, prompting initiatives to broaden its use for breast cancer treatment. Switching to goserelin LA can streamline treatment, boost adherence, and optimize resource utilization. With the recent approval of goserelin 10.8 mg LA by Health Canada on 6 May 2024, for use in breast cancer, Canada is the latest to join over 60 countries worldwide to expand the accepted indications for goserelin LA and ensure its availability to potentially enhance healthcare delivery, patient care, and breast cancer outcomes. Goserelin LA offers premenopausal patients a means to more effectively manage the constraints imposed by breast cancer treatment and its impact on survivorship.

Circulating tumour mutation detection in triple-negative breast cancer as an adjunct to tissue response assessment.

Circulating tumour DNA (ctDNA) detection via liquid biopsy is an emerging alternative to tissue biopsy, but its potential in treatment response monitoring and prognosis in triple negative breast cancer (TNBC) is not yet well understood. Here we determined the prevalence of actionable mutations detectable in ctDNA using a clinically validated cancer gene panel assay in patients with TNBC, without recurrence at the time of study entry. Sequencing of plasma DNA and validation of variants from 130 TNBC patients collected within 7 months of primary treatment completion revealed that 7.7% had detectable residual disease with a hotspot panel. Among neoadjuvant treated patients, we observed a trend where patients with incomplete pathologic response and positive ctDNA within 7 months of treatment completion were at much higher risk of reduced progression free survival. We propose that a high risk subset of early TNBC patients treated in neoadjuvant therapy protocols may be identifiable by combining tissue response and sensitive ctDNA detection.

Current and New Novel Combination Treatments for Metastatic Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) has a worse prognosis and remains the most challenging breast cancer subtype to treat. This is largely related to the heterogeneity of this disease and the lack of reliable oncological targets. In this review, we discuss the current standard-of-care treatment options for metastatic TNBC, including recent advances with the use of immunotherapy, PARP inhibitors and antibody-drug conjugates. This review also explores new agents and novel combinations arising in the field for the treatment of advanced TNBC.

Locoregional Recurrence and Survival Outcomes in Breast Cancer Treated With Modern Neoadjuvant Chemotherapy: A Contemporary Population-based Analysis.

BACKGROUND: Data guiding radiotherapy (RT) decisions after neoadjuvant chemotherapy (NAC) is largely retrospective, based on older treatment approaches without molecular subtype information. This study evaluated outcomes in breast cancer patients treated with modern NAC by molecular subtype and locoregional treatment. MATERIALS AND METHODS: There were 949 patients diagnosed between 2005 and 2016 treated with NAC followed by surgery ± locoregional radiotherapy (LRRT). Outcomes were 7-year locoregional relapse-free survival (LRRFS), breast cancer-specific survival (BCSS), and overall survival (OS). RESULTS: Median follow-up was 6.5 years, 92% had cT2-4 and 72% cN1-3 disease. Subtypes were: 21% Luminal A, 18% Luminal B, 35% Her2+, and 21% triple-negative breast cancer (TNBC). Combined taxane and anthracycline-based NAC was used in 91.7% of cases. All patients with Her2+ disease received anti-Her2 therapy. After NAC, the majority (84.9%) underwent mastectomy, and received LRRT (86.1%). Only 11% had mastectomy without RT. Pathologic complete response (pCR) rates were 2.5% for Luminal A, 14.4% Luminal B, 27% TNBC, and 35.1% Her2+. Overall, adjuvant LRRT was associated with improved outcomes but was most significant for improved LRRFS in TNBC (92.5% vs. 68.5%, P < .001; Her2+ 95.4% vs. 93.6%, P = .81; Luminal A 97.4% vs. 100%, P = .49; Luminal B 89.7% vs. 100%, P = .17). On multivariable analysis, factors associated with reduced LRRFS were grade 3 histology (HR 4.96, P = .009) and no pCR (HR 7.0, P = .0008). Predictors of lower BCSS and OS were age >50, grade 3, cT3-4, lack of pCR, LRRT omission, and TNBC and Her2+ subtypes. CONCLUSION: In this analysis of patients treated with modern NAC, pCR rates varied by molecular subtype. Patients who did not receive LRRT, particularly those with TNBC, had lower survival compared to those treated with LRRT. These findings support the need for prospective studies to evaluate the safety of de-escalating RT after NAC.

Impact of the 21-Gene Recurrence Score Assay on the Treatment of Estrogen Receptor-Positive, HER2-Negative, Breast Cancer Patients With 1-3 Positive Nodes: A Prospective Clinical Utility Study.

PURPOSE: The use of the 21-gene Recurrence Score (RS) assay is emerging in node-positive estrogen receptor (ER)+ HER2-negative breast cancer (BC), particularly as initial data from the RxPONDER trial are now available. We investigated the impact of the RS result on adjuvant treatment decisions in such patients. PATIENTS AND METHODS: This prospective, multi-center study enrolled patients with ER+, HER2-negative BC and 1 to 3 positive nodes (microscopic [N1mi] or macroscopic [N1]). Treating oncologists documented treatment recommendations/plan before and after knowing the RS result. Sample size was determined assuming an overall treatment change rate (from chemohormonal therapy [CHT] to hormone therapy [HT] and vice-versa) of ≥30%. RESULTS: The study included 84 patients across 5 regional cancer centers, of whom 82 underwent 21-gene testing (77%, N1 disease; 63% grade 2 tumors). Of the RS-tested patients, 60%, 33%, and 7% had RS 0 to 17, 18 to 30, and 31 to 100, respectively. In 43 patients (52%), treatment changed post-RS: 40 patients (49%) from CHT to HT and 3 patients (4%) from HT to CHT. The net change was a 45% reduction in chemotherapy use. Treatment recommendation changes were consistent with the RS result. In RS 0 to 17 patients, the only documented change was from CHT to HT (27 patients). In RS 18-30 patients, change was noted in both directions (CHT-to-HT, 13 patients; HT-to-CHT, 3 patients). No treatment change was reported for the RS 31 to 100 patients, all of whom were recommended CHT pre-testing. CONCLUSION: Our results support the clinical utility of the RS assay in ER+ HER2-negative BC with 1 to 3 positive nodes.

Breast Cancer Molecular Subtype as a Predictor of Radiation Therapy Fractionation Sensitivity.

PURPOSE: The predictive benefit of breast cancer molecular subtypes for systemic therapy approaches has been well established; yet, there is a paucity of data regarding their use as a predictor of radiation therapy fractionation sensitivity. The purpose of this study was to determine whether rates of local recurrence (LR) for patients treated with hypofractionated (HF) radiation therapy, in comparison to conventional fractionation, differ across breast cancer molecular subtypes in a large, prospectively collected cohort treated with modern systemic therapy. METHODS AND MATERIALS: Patients who received a diagnosis of stage I-III breast cancer between 2005 and 2009 were identified. Molecular subtype was determined using the American Joint Committee on Cancer classification system (luminal-A, luminal-B, HER2+, triple negative [TN]). Multivariable Cox regression modeling was used to identify predictors of LR. LR-free-survival (LRFS) was determined using the Kaplan-Meier method and compared using the log-rank test. RESULTS: A total of 5868 cases were identified with a median follow-up of 10.8 years. Patients with luminal-A subtype composed 45% of the cohort (n = 2628), compared with 30% luminal-B (n = 1734), 15% HER2+ (n = 903), and 10% TN (n = 603). A total of 76% (n = 4429) of patients were treated with HF. The 10-year LRFS was 97.1% (95% confidence interval [CI], 96.6-97.6) for the whole cohort. The 10-year LRFS based on molecular subtypes was 98.3% (95% CI, 97.6-98.7) luminal-A, 96.6% (95% CI, 95.5-97.4) luminal-B, 97.0% (95% CI, 95.5-98.0) HER2+, and 93.5% (95% CI, 91.1-95.3) TN (P < .001). There was no difference in the 10-year LRFS between patients treated with HF versus conventional fractionation among those with luminal-A (98.2% vs 98.4%; P = .42), luminal-B (96.6% vs 96.8%; P = .90), HER2+ (97.5% vs 95.8%; P = .12), or TN (93.9% vs 92.2%; P = .47). There was no significant interaction between subtype and fractionation regimen. CONCLUSIONS: These data support the routine use of hypofractionated radiation therapy regimens across all breast cancer subtypes.

Optimising weight-loss interventions in cancer patients-A systematic review and network meta-analysis.

BACKGROUND: Excess weight has been associated with increased morbidity and a worse prognosis in adult patients with early-stage cancer. The optimal lifestyle interventions to optimize anthropometric measures amongst cancer patients and survivors remain inconsistent. OBJECTIVE: To conduct a systematic review and network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing the effects of exercise and dietary interventions alone or in combination on anthropometric measures of adult cancer patients and survivors. METHODS: A systematic search of Medline, Embase and the Cochrane Trials Registry was performed. Outcomes of interest included changes in weight, body mass index (BMI), and waist circumference. Screening and data collection were performed by two reviewers. Bayesian NMAs were performed. RESULTS: Overall, 98 RCTs were included; 75 were incorporated in NMAs (n = 12,199). Groups of intervention strategies included: 3 exercise interventions, 8 dietary interventions, 7 combination interventions of diet and exercise and standard care. Median intervention duration was 26 weeks. NMA suggested that diet alone (mean difference [MD] -2.25kg, 95% CrI -3.43 to -0.91kg) and combination strategies (MD -2.52kg, 95% CrI -3.54 to -1.62kg) were associated with more weight loss compared to standard care. All dietary interventions achieved a similar magnitude of weight loss (MD range from -2.03kg to -2.52kg). Both diet alone and combination strategies demonstrated greater BMI reductions versus standard care, and each of diet alone, exercise alone and combination strategies demonstrated greater reductions in waist circumference than standard care. CONCLUSION: Diet and exercise alone or in combination are effective lifestyle interventions to improve anthropometric measures in cancer patients and survivors. All reputable diets appear to be similarly effective to achieve weight loss.

Impact of pathologic complete response on survival after neoadjuvant chemotherapy in early-stage breast cancer: a population-based analysis.

BACKGROUND: Achieving a pathologic complete response (pCR) has been associated with improved long-term outcomes in clinical trials. However, the benefit of achieving pCR across subtypes and its prognostic effect on real-world outcomes has not been well described. METHODS: A retrospective analysis of the Breast Cancer Outcomes Unit database was undertaken to identify patients with stage I-III breast cancer treated with neoadjuvant chemotherapy from 2005 to 2010 in British Columbia. Patients were separated into two groups: those with pCR and those with residual invasive disease in the breast/axillary lymph nodes (RD). The primary endpoint was relapse-free survival (RFS). Key secondary endpoints included breast cancer-specific survival (BCSS) and overall survival (OS). RESULTS: Of 267 patients identified, 74 patients (28%) achieved pCR and 193 patients (72%) had RD. Median follow-up was 7.5 years. The 5-year RFS was higher in the pCR group compared to the RD group (84% vs 70%; HR 0.45, p = 0.011). The 5-year BCSS was also higher in the pCR group than in the RD group (90% vs 77%; HR 0.39, p = 0.014). In multivariable analyses, pCR was associated with improved RFS (HR 0.39, p = 0.0077) and BCSS (HR 0.35, p = 0.015), whereas traditional pathological prognostic factors were not. Patients with TNBC who achieved pCR had improved RFS and BCSS compared to those with RD (HR 0.26, p = 0.020 and HR 0.35, p = 0.090, respectively). A similar but non-statistically significant trend was seen in the HER-2-positive and ER + subtypes. CONCLUSIONS: Achieving pCR after neoadjuvant chemotherapy was associated with clinically meaningful improvements in survival parameters in a real-world setting. The cumulative data support pCR as a valid surrogate endpoint in both clinical trials and population-based settings.

Efficacy of Neoadjuvant Endocrine Therapy Versus Neoadjuvant Chemotherapy in ER-positive Breast Cancer: Results From a Prospective Institutional Database.

BACKGROUND: Although neoadjuvant chemotherapy (NACT) has been established as a standard for medically fit patients with locally advanced breast cancer, there has been renewed interest in utilizing neoadjuvant endocrine therapy (NET) for women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer. Rates of pathologic complete response (pCR) are known to be low, but data regarding down-staging and long-term outcomes are inconsistent. PATIENTS AND METHODS: A prospective institutional database of patients with breast cancer treated with neoadjuvant therapy from 2012 to 2017 was analyzed to identify patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer. Patients who received NET were compared with those who received NACT. A matched analysis (age, stage, grade) was performed to compare rates of down-staging, pCR, breast conserving surgery, and CPS+EG scores. RESULTS: A total of 176 patients met eligibility criteria. Of these, 111 (63%) patients received NACT, 51 (29%) received NET, and 14 (8%) received both sequentially. Women prescribed NET were older (65.5 vs. 51.2 years; P < .0001) and presented with lower clinical stage (P < .0001). The median duration of NET was 90 days. When matched, clinical down-staging was more frequent with NACT (20/51; 39%) compared with NET (11/51; 22%) (P = .032). Of these, 2% achieved pCR in each cohort. Conversion rates to breast conserving surgery eligibility were low (8% and 13% with NET and NACT; P = .70). No significant differences in CPS+EG scores were identified. CONCLUSIONS: Significantly higher rates of down-staging were achieved with NACT compared with NET when patients were matched. This study highlights the importance of establishing tumor biology and the need for biomarkers that can be used as predictive tools to inform treatment.