Rate Of Breast-conserving Surgery Research Articles

Predictors of mastectomy in breast cancer patients with complete remission of primary tumor after neoadjuvant therapy: A retrospective study

IntroductionNeoadjuvant therapy (NAT) should increase the rate of breast-conserving surgery (BCS) in non-metastatic breast cancer (BC) patients, especially in those achieving tumor shrinkage. Still, the conversion from a pre-planned mastectomy to BCS in patients responding to NAT is not a widespread standard. We aimed to identify factors influencing surgical choices in this setting. Materials and methodsWe retrospectively collected data of BC patients with complete remission of primitive tumor (ypT0) after NAT, treated with BCS or mastectomy in two Italian breast units. Predictors of mastectomy were explored using logistic regression. Distant recurrence and event-free survival were assessed in the BCS and mastectomy cohort. Results243 patients were included, 147 (60.5 %) treated with BCS and 96 (39.5 %) treated with mastectomy. In the mastectomy group, there were more centrally-located, multiple and larger tumors. At univariate regression analysis, central location, baseline tumor extension on ultrasound (US) and magnetic resonance imaging (MRI), multiple foci and clinical stage were significantly associated with the chance of receiving mastectomy. At multivariate analysis, only baseline focality on US and extension on MRI retained significance as predictors of mastectomy. Distant recurrence and event-free survival were significantly longer in patients undergoing BCS. ConclusionBaseline tumor extension and focality were the main predictors of mastectomy in patients with ypT0 after NAT. However, BCS did not negatively affect survival outcomes in our cohort. An effort should be made to avoid potentially unnecessary mastectomy in this population, aiming at minimizing surgery-associated toxicities and improving patients’ quality of life.

The impact of advanced oncoplastic surgery on breast-conserving surgery rates: A retrospective cohort study of 3,875 breast cancer procedures at a tertiary referral centre

IntroductionAs the treatment of breast cancer advances, the focus has shifted from solely improving oncological endpoints to a greater weight being placed on cosmetic and psychological outcomes. The advent of advanced oncoplastic techniques allows for successful breast-conserving surgery (BCS) to patients who otherwise would have required a mastectomy. The aim of this study is to ascertain if the adoption of these procedures has assisted in the reduction of mastectomies performed. MethodsA dataset of all breast cancer procedures based upon coding between April 2016 and July 2023 was evaluated, categorising procedures into: BCS, mastectomy, oncoplastic BCS and total reconstructions. R-Studio Software 4.3.1 (®) was used to explore statistical analysis and data visualisation. Registered as a clinical services evaluation study (Project ID: 14649). ResultsDuring the period stated, 3875 index breast cancer procedures were recorded (sample size = 3638 patients). The BCS rate increased from 66.2 % in 2016 to 80.7 % in 2023. Using a linear regression model, the BCS rate demonstrates an increase of 2.1 % each year (coefficient = 2.12, p-value = 0.0069). Concurrently, the rate of oncoplastic BCS increased from 10.5 % to 22.9 % (coefficient = 2.14, p-value = 0.00017). Using Pearson's product-moment, a positive correlation between these two variables is seen (coefficient = 0.86, p-value = 0.0056). ConclusionHaving reviewed 3875 index breast cancer procedures over the past eight years, the BCS rate has shown a statistically significant increase and a positive correlation with the oncoplastic BCS rate. This suggests oncoplastic surgery has helped to reduce the rates of mastectomy at the centre.

Quantitative Biomarkers, Genomic Assays, and Demographics Associated with Breast-Conserving Surgery Following Neoadjuvant Therapy in Early-Stage, Hormone Receptor-Positive, HER-Negative Breast Cancer

BackgroundGiven increased neoadjuvant therapy use in early-stage, hormone receptor (HR)-positive/HER2-negative breast cancer, we sought to quantify likelihood of breast-conserving surgery (BCS) after neoadjuvant chemotherapy (NACT) or endocrine therapy (NET) as a function of ER%/PR%/Ki-67%, 21-gene recurrence scores (RS), or 70-gene risk groups.MethodsWe analyzed the 2010–2020 National Cancer Database. Surgery was categorized as “mastectomy/BCS.” Logistic regression was performed. Adjusted odds ratios (AOR) were per 10-unit increase in ER%/PR%/Ki-67%.ResultsOverall, 42.3% underwent BCS after NACT, whereas 64.0% did after NET. Increasing ER% (AOR = 0.96, 95% confidence interval [CI] 0.94–0.97) or PR% (AOR=0.98, 95% CI 0.96–0.99) was associated with lower odds of BCS after NACT. Increasing Ki-67% was associated with greater odds of BCS (AOR = 1.07, 95% CI 1.04–1.10). Breast-conserving surgery rates increased by ~20 percentage points, with Ki-67% ≥15 or RS >20. Patients with a low (43.0%, AOR = 0.50, 95% CI 0.29–0.88) or intermediate (46.4%, AOR = 0.58, 95% CI 0.41–0.81) RS were less likely than patients with a high RS (65.0%) to undergo BCS after NACT. Increasing ER% was associated with higher odds of BCS after NET (AOR = 1.09, 95% CI 1.01–1.17). Breast-conserving surgery rates increased by ~20 percentage points between ER <50% and >80%. In both cohorts, the odds of BCS were similar between 70-gene low-risk and high-risk groups. Asian or uninsured patients had lower odds of BCS.ConclusionsNeoadjuvant chemotherapy is unlikely to downstage tumors with a low-intermediate RS, higher ER%/PR%, or lower Ki-67%. Breast-conserving surgery after NET was most dependent on ER%. Findings could facilitate treatment decision-making based on tumor biology and racial/socioeconomic disparities and improve patient counseling on the likelihood of successful BCS.

Increasing opportunities for breast-conserving therapy in multiple ipsilateral breast cancer: Dutch nationwide study.

An increasing number of breast cancer patients undergo breast-conserving surgery (BCS), but multiple ipsilateral breast cancer (MIBC) is still considered a relative contraindication for breast conservation. This study provides an update on trends in the surgical management for MIBC over a 10-year period. Nationwide data from the Netherlands Cancer Registration of all patients diagnosed with breast cancer between 2011 and 2021 were analysed. The primary outcomes of this study were the incidence of MIBC and the trend in breast surgery type among patients between 2011 and 2021. Secondary outcomes were the positive resection margin rates in patients treated with BCS, the proportion of patients requiring re-excision and overall survival. In total, 114 433 patients (83%) with unifocal breast cancer and 23 932 patients (17%) with MIBC were identified. The incidence of MIBC was stable (17%) over the years. Overall BCS rates, both primary and after neoadjuvant chemotherapy, increased in MIBC from 29% in 2011 to 41% in 2021. Re-excision was performed in 1348 patients (n = 8455, 16%). The 5-year OS estimate for patients with MIBC treated with BCS was 93%. The pathological complete response (pCR) in MIBC patients treated with neoadjuvant chemotherapy followed by mastectomy was 23%. The breast conservation rate in MIBC has increased over the last decade. In addition, 23% of MIBC patients treated with neoadjuvant chemotherapy followed by mastectomy achieved a pCR. This suggests increasing opportunities for even more BCS in MIBC.

A randomized controlled study of neoadjuvant metformin with chemotherapy in nondiabetic breast cancer women: The METNEO study.

Clinical data demonstrate that metformin exhibits antiproliferative, proapoptotic and antimetastatic actions. Here, correlative molecular studies were undertaken to determine the roles of transmembrane tumour necrosis factor-related apoptosis-inducing ligand death receptors (DRs) and CD133, a glycoprotein biomarker of breast cancer (BC) stem cells, in the advantageous action of metformin on pathological and clinical outcomes in BC patients on neoadjuvant chemotherapy. We randomly assigned 70 nondiabetic BC patients in a 1:1 ratio to either neoadjuvant AC-T chemotherapy (4cycles of adriamycin 60 mg/m2 and cyclophosphamide 600 mg/m2, followed by 12 cycles of weekly paclitaxel 80 mg/m2) or AC-T with adjunct metformin (850 mg twice/day). The expressions of DR4, DR5 and CD133 were quantified in excised tissue samples with residual tumour cells. The overall clinical response (odds ratio: 22.67 [2.77-185.18], P= .004), breast-conserving surgery (odds ratio: 3.67 [1.303-10.321], P= .014) and pathological complete response (β =2.49 ±1.13 [0.274-4.712], P= .028) rates were significantly improved in the metformin arm. Tissues obtained from the metformin arm had upregulated mRNA expression of DR4 (Mean delta cycle thresholds ± standard error of the mean: 2.68 ±0.25 vs. 4.87 ±0.53, P= .0003) and DR5 (0.21 ±0.25 vs. 4.29 ±0.95, P= .0004) compared to control arm. The enhanced DR expression negatively correlated with that of CD133 + BC stem cells, which was significantly reduced by metformin at both cytoplasmic/membranous (43.48 vs. 100.00%, P< .0001) and nuclear sites (4.35 vs. 95.00%, P< .0001). Metformin improves clinical and pathological responses to neoadjuvant AC-T chemotherapy in BC via prompting directionally opposite changes in DRs (increments) and CD133 + (decrements) expressions. This study was registered in ClinicalTrials.gov (registration number: NCT04170465, https://clinicaltrials.gov/ct2/show/NCT04170465).

The current diagnosis and treatment strategy of breast cancer based on multicentre retrospective data in Shaanxi province

BackgroundBreast cancer is a common malignancy, and early detection coupled with standardized treatment is crucial for patient survival and recovery. This study aims to scrutinize the current state of breast cancer diagnosis and treatment in Shaanxi province, providing valuable insights into the local practices and outcomes.MethodsWe selected 25 hospitals that typically represent the current diagnosis and treatment strategy of breast cancer in Shaanxi (a province in northwest China). The questionnaire comprised sections on fundamental information, outpatient consultations, breast-conserving surgery, neoadjuvant and adjuvant therapy, sentinel lymph node biopsy, breast reconstruction surgery.ResultsA total of 6665 breast cancer operations were performed in these 25 hospitals in 2021. The overall proportion of breast-conserving surgery (BCS) is 23.6%. There was a statistically significant positive correlation between the annual volume of breast cancer surgery and the implementation rate of BCS (P = 0.004). A total of 2882 cases of neoadjuvant treatment accounted for 43.24% of breast cancer patients treated with surgery in 2017. Hospitals in Xi’an performed more neoadjuvant therapy for patients with breast cancer compared to other districts (P = 0.008). There was a significantly positive correlation between outpatient visits and the implementation rate of sentinel lymph node biopsy (SLNB) (P = 0.005). 14 hospitals in Shaanxi performed reconstructive surgery.ConclusionsBreast conserving surgery, adjuvant and neoadjuvant therapy and sentinel lymph node biopsy in Shaanxi province have reached the China’s average level. Moreover, hospitals in Xi ’an have surpassed this average. However, a disparity is observed in the development of breast reconstruction surgery when compared to top-tier hospitals.

PROMRIINE (PRe-operatory Magnetic Resonance Imaging is INEffective) Study: A Systematic Review and Meta-analysis of the Impact of Magnetic Resonance Imaging on Surgical Decisions and Clinical Outcomes in Women with Breast Cancer

BackgroundThe purpose of this study was to review and summarize the association between preoperative magnetic resonance imaging (MRI) and surgical outcomes in women with newly diagnosed invasive breast cancer from published randomized controlled trials (RCT).Materials and MethodsTwo independent researchers conducted a systematic review through a comprehensive search of electronic databases, including PubMed, Medline, Embase, Ovid, Cochrane Library, and Web of Science. If there was disagreement between the two reviewers, a third reviewer assessed the manuscript to determine whether it should be included for data extraction. The quality of the papers was assessed using the risk of bias tool, and the evidence was analyzed using GRADE. Meta-analyses using a fixed-effects model were used to estimate the pooled risk ratio (RR) and 95% confidence interval (CI).ResultsInitially, 21 studies were identified, 15 of which were observational comparative studies. A total of five RCTs were included, and they suggested that preoperative MRI significantly reduced the rate of immediate breast-conserving surgery and increased the risk for mastectomy.ConclusionsFrom the RCT perspective, preoperative MRI for newly diagnosed invasive breast cancer did not improve surgical outcomes and may increase the risk of mastectomy.

Personalized neoadjuvant strategy in ER positive and HER2 negative breast cancer to increase BCS rate (PLATO): A prospective, multicenter, phase II clinical trial.

595 Background: Neoadjuvant therapy significantly enhances the likelihood of breast-conserving surgery (BCS) in breast cancer patients. However, in ER-positive and HER-2 negative breast cancer, the response to neoadjuvant chemotherapy (NCT) is not as good as HER-2 positive or triple-negative breast cancer. In addition, with the evolution of multi-gene assays, many patients of this subtype may not require adjuvant chemotherapy. This study explores the potential of tailored neoadjuvant treatments (NCT or endocrine therapy (NET)) guided by 70-gene assay (Mammaprint, Agendia) to improve BCS rates in ER-positive/HER-2 negative breast cancer. Methods: A prospective, multicenter cohort study was conducted across four Korean centers from 2019 to 2023. Participants were clinical stage II-IIIA, ER-positive/HER2-negative breast cancer patients deemed unsuitable for BCS. Suitability was further verified by an independent three-surgeon panel using mammography or MRI. Out of 130 screened patients, 100 were enrolled. We analyzed 90 patients, excluding 10 cases; 2 with a basal type or HER2 type result in the blueprint, 7 who refused neoadjuvant therapy, and 1 who underwent surgery at another hospital. Before initiation of therapy, each surgeon recorded a target tumor size at which the surgeon would be able to do BCS considering location of the tumor and patient’s breast size. Based on the 70-gene assay results from core needle biopsies, high-genomic-risk patients received NCT (anthracycline + cyclophosphamide for 4 cycles, followed by 4 cycles of docetaxel), while low-risk patients underwent 16 weeks of NET with letrozole (±leuprolide for premenopausal women). Results: Out of the patients, 66 (73%) were high-genomic-risk and underwent NCT, while 24 (27%) received NET. Median tumor size was 3.7cm (85.6% clinical T2 and 14.4% T3/4). The primary endpoint, achieving the pre-established target tumor size for BCS, was reached by 70.0% (95% CI: 59.4-79.2%) of patients, significantly surpassing the set goal of 50.8% (a 15% increase from historical control). The rates were 74.2% for NCT and 58.3% for NET. The actual BCS rate was 58.9% overall (63.6% for NCT and 45.8% for NET). Clinically, 5.6% exhibited complete response (CR), 74.4% partial response (PR), 18.8% stable disease (SD), and 1.1% progressive disease (PD). Pathologic complete response (pCR) was achieved in 2.2% (all in the NCT group). No severe adverse events beyond expectations were observed. No pre-treatment clinical or pathological factor was significantly predictive for the BCS conversion. Conclusions: For ER positive, HER2 negative breast cancer patients initially ineligible for BCS, the use of pre-treatment multi-gene assays to guide selective NCT or NET could substantially increase BCS rates and reduce unnecessary chemotherapy. Clinical trial information: NCT03900637 .

Clinicopathological features and prognosis for pregnancy-associated breast cancer: A matched case-control study.

e12573 Background: Pregnancy-Associated Breast Cancer (PABC) is defined as breast cancer diagnosed during pregnancy or within 1 year postpartum. Studies indicate that PABC tends to have poorer prognostic characteristics and often worse outcomes compared to non-PABC. The primary goal of this study is to examine disease characteristics associated with PABC versus non-PABC in the United Arab Emirates (UAE), where breast cancer is characterized by a younger age and more advanced stage compared to North America and Europe. Additionally, the UAE has a younger mean age for first-time mothers and a similar age for all mothers compared to North America and Europe. Methods: Patients with PABC were selected from BC cases of women ≤40 years treated at Tawam Hospital, the largest tertiary cancer center in the UAE between January 2003 – December 2020. Each PABC patient was matched to two non-PABC patients (controls) according to cancer stage, age, and year of diagnosis. The Fisher's exact and Kruskal-Wallis tests were used to compare both study groups. Results: 66 women with PABC were identified, with a median age at diagnosis of 33.0 (interquartile range [IQR]: 30.0-37.0) years. Most presented with stage II (45.5%) or stage III (39.4%) disease and underwent mastectomy and axillary lymph node dissection. Invasive ductal carcinoma was the most frequent histological type in both groups (86.4% for PABC and 85.6% for non-PABC). PABC was associated with higher grade 3 disease compared with non- PABC (53% vs 51.5% p= 0.009). More women with PABC received neoadjuvant chemotherapy (NACT) and radiation therapy (RT) compared with non-PABC (48.5% vs 3%, p &lt;0.001 and 80.3% vs 65.9%, p= 0.046, respectively). There were no statistically significant differences with regards to tumor size, nodal involvement, underlying histologic subtype, ER/PR expression or HER-2 status, rates of breast-conserving surgery and adjuvant chemotherapy receipt between the two groups. The median progression-free survival (PFS) was 3.2 years (IQR: 1.9-7.1) in PABC and 3.4 years (IQR: 1.2-6.2) in non-PABC group (P=0.306). The median overall survival (OS) was 4.5 years in the PABC (IQR: 2.4-7.9) versus 4.5 years (IQR: 1.9-7.9) in the non-PABC group (P = 0.786). Conclusions: PABC in women ≤40 years appears to be associated with grade III tumors and NACT and RT receipt compared to non-PABC. However, there were no significant difference in PSF and OS between PABC and non-PABC. Further analysis is underway to evaluate the prognostic factors and their effect on survival.

A propensity-matched cohort study of neoadjuvant immunotherapy combined with chemotherapy versus neoadjuvant chemotherapy for early-stage triple-negative breast cancer.

e13134 Background: Preferred neoadjuvant treatment (NAT) regimens for early-stage triple-negative breast cancer (TNBC) include anthracycline-cyclophosphamide and taxane-based chemotherapy. This study compared the efficacy, safety and biomarker exploration of camrelizumab combined with chemotherapy and chemotherapy as neoadjuvant treatment for early-stage TNBC. Methods: This study included 2 cohorts with different NAT regimens, matched (2:1) according to age, clinical T and N stage, and Ki-67 status. Patients in the immune combination chemotherapy (NIC) cohort were recruited from a phase II clinical trial (NCT04676997). NIC patients received intravenous camrelizumab at a dose of 200mg and simultaneous chemotherapy consisted of platinum-free drugs, or platinum containing drugs. Patients in the neoadjuvant chemotherapy (NAC) cohort regimen comprised 4 cycles of paclitaxel 175 mg/m2, and 4 cycles of epirubicin (90 mg/m2, d1, q2w) + cyclophosphamide (600 mg/m2, d1, q2w). The indicators of this study include pCR, breast pCR (bpCR), axillary lymph node dissection (ALND) rate, breast conserving surgery (BCS) rate and tumor immune microenvironment (TIME) analysis of gene expression profiling. Results: Of 252 eligible patients, 162 patients were identified in the analysis after propensity score matching (PSM). Compared with NAC alone, the addition of camrelizumab brought higher pCR rates (64.81% versus 37.04%, p&lt;0.05), ALND rates (38.89% versus 12.96%, p&lt;0.05) and comparable BCS rates (20.37% versus 15.74%, p&lt;0.05). Gene expression analysis was performed on tumor tissue samples from 12 patients receiving NAC and 16 patients receiving NIC before and after NAT. The results showed that the TIME status of the NIC and NAC groups before treatment was basically the same. Moreover, we respectively compared the TIME status of patients with pCR and non_pCR in NIC and NAC before NAT. The results found that there were 9 significantly different signatures (p&lt;0.05) between pCR and non_pCR patients in the NIC group, and 1 signature (p&lt;0.05) in the NAC group, respectively. Notably, we found 8 signatures (B Cells, CD8 T Cells, TIS, IFN Gamma, Lymphoid, T Cell, APM, Immunoproteasome), that were scored significantly higher only in pCR patients in the NIC group compared with non-pCR patients, and 8 signatures could promote response to immunotherapy. The common difference signature between the two groups is Treg cells. Conclusions: In patients with early-stage TNBC, neoadjuvant treatment with camrelizumab plus chemotherapy significantly improved pCR with an acceptable safety profile. Differences in TIME may affect response to treatment regimens. Future validation in prospective randomized controlled trials with larger sample sizes is needed. Clinical trial information: NCT04676997 .

Oncologic Safety of Immediate Oncoplastic Surgery Compared with Standard Breast-Conserving Surgery for Patients with Invasive Lobular Carcinoma

BackgroundInvasive lobular carcinoma (ILC) of the breast grows in a diffuse pattern, resulting in a high risk of positive margins at surgical resection. Oncoplastic approaches have been shown to reduce this risk, but concerns persist around the safety of immediate oncoplastic surgery for those with ILC. This study evaluated the short- and long-term oncologic outcomes of immediate oncoplastic surgery for patients with ILC.MethodsThis study retrospectively analyzed an institutional database of stages I to III ILC patients who underwent breast-conserving surgery (BCS) with or without immediate oncoplastic surgery (oncoplastic closure or oncoplastic reduction mammoplasty [ORM]). The study compared positive margin rates, rates of successful BCS, and recurrence-free survival (RFS) by type of surgery.ResultsFor 494 patients the findings showed that the use of immediate ORM was associated with significantly lower odds of positive margins (odds ratio [OR], 0.34; 95 % confidence interval [CI], 0.17–0.66; p = 0.002). Both lumpectomy with oncoplastic closure and ORM were significantly associated with higher rates of successful BCS than standard lumpectomy (94.2 %, 87.8 %, and 73.9 %, respectively; p < 0.001). No difference in RFS was observed between those undergoing immediate oncoplastic surgery and those undergoing standard lumpectomy alone.ConclusionsThe patients with stages I to III ILC who underwent immediate oncoplastic surgery had significant benefits including lower odds of positive margins and higher rates of successful BCS, with both types of immediate oncoplastic surgery showing similar RFS compared with lumpectomy alone. This supports the oncologic safety of immediate oncoplastic surgery for diffusely growing tumors such as ILC, providing it an ideal option for patients desiring BCS.

Abstract PO1-28-04: PILHLE-001: neoadjuvant pyrotinib combined with chemotherapy in HR-positive, HER2-low (IHC 2+/FISH-negative) early breast cancer

Abstract Background: Hormone receptor (HR)-positive/HER2-low (IHC 2+/FISH negative or IHC 1+) breast cancers (BCs) represent the largest proportion of breast carcinomas. However, its response to neoadjuvant chemotherapy or endocrine therapy is the lowest, with a residual cancer burden (RCB) 0/I rate around 15%. Previous studies have demonstrated that pyrotinib (P), a pan-HER tyrosine kinase inhibitor, exhibits excellent response in HER2-positive early or advanced BC (E/ABC). In-vitro experiments have shown that pyrotinib can effectively inhibit colony formation in HER2-low (IHC 2+/FISH negative) BC cells. This PILHLE-001 study (NCT05165225) aimed to evaluate the efficacy and safety of neoadjuvant pyrotinib plus chemotherapy in HR-positive/HER2-low (IHC 2+/FISH negative) EBC patients with potential biomarkers. Methods: PILHLE-001, as a single-arm, single-center phase Ⅱ trial, enrolled patients with previously untreated HR-positive (ER or PR &amp;gt; 1%) and HER2-low (IHC 2+/FISH negative) invasive EBC (TNM stage II-III) to receive pyrotinib 320mg QD and four Q3W of epirubicin-cyclophosphamide followed by four Q3W of docetaxel. MammaPrint/BluePrint at baseline (t0) was assessed. Breast magnetic resonance imaging (MRI) was conducted at t0, the end of cycle 2 neoadjuvant therapy (t1), and the end of all neoadjuvant therapy. Immune cell subpopulations assay and gene sequencing of tumor tissues with whole blood control samples were performed at t0 and surgery (t2). Additional core biopsy was administered to reassess Ki67 and tumor infiltrating lymphocytes (TILs) at t1. The primary outcome was RCB 0/I rate. The short-term secondary outcomes included pathological complete response (pCR, ypT0/is ypN0) rate, objective response rate (ORR), breast conservation surgery (BCS) rate, safety, and exploratory biomarkers analysis. Results: From July 2021 to March 2023, 48 patients were enrolled and treated. The median age of the patients was 48 years (range 28-66), 43 (90%) had cT1-2 tumors, 30 (63%) showed no node involvement, 37 (77%) had tumours with TNM stage II, and 47 (98%) had ER expression ≥ 50%. Twenty-eight (61%) of 46 patients had MammaPrint high risk. Out of the 48 patients, 26 (54.2%) achieved RCB 0/I, with a 95% confidence interval of 39.2% to 68.6%. The RCB 0/I rate was particularly higher in tumors with no lymph node involvement (73.3%), TNM stage II (64.9%), or abundant tumor-infiltrating lymphocytes (66.7%). Three (6.3%) patients obtained a pCR. The rate of BCS was 60.4% (29/48). The ORR was 45.8% (22/48) at t1 and 81.3% (39/48) at the end of all neoadjuvant therapy, respectively. No patients had progressive disease. All treatment-related adverse events (AEs) were mostly of grade 1 or 2 severity. Grade ≥ 3 AEs occurred in 21 (44%) patients, with the most prevalent being diarrhea [10 (21%)]. All AEs were reversible with symptomatic treatment and no treatment-related deaths occurred. Patients with MammaPrint risk-low BC had a lower RCB 0/I rate than those with risk-high BC (60.7% vs. 44.4%), although the difference was not statistically significant. Baseline specific immune cell subpopulations (lower PD-1, higher CD3, etc.) or the presence of non-altered PIK3CA were significantly associated with a higher likelihood of achieving RCB 0/I. Similarly, objective response, greater declines in specific MRI quantitative parameters (Ktrans and Kep), greater declines in Ki67, or more increased TILs at t1 were also significantly associated with a higher rate of RCB 0/I. Conclusions: The PILHLE-001 trial first revealed that neoadjuvant pyrotinib plus chemotherapy has encouraging efficacy and acceptable toxicity in patients with HR-positive/HER2-low (IHC 2+/FISH negative) EBC, and this regimen warrants further investigation in phase III randomized controlled trials. Citation Format: Chang Gong, Yuan Xia, Yingying Zhu, Yaping Yang, Wenqian Yang, Louis W.C. Chow, Li Ling, Yunjie Zeng, Jiajie Zhong, Ziliang Cheng, Jun Shen, Qun Lin, Yinduo Zeng, Qiang Liu, Erwei Song. PILHLE-001: neoadjuvant pyrotinib combined with chemotherapy in HR-positive, HER2-low (IHC 2+/FISH-negative) early breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-28-04.

Abstract PO5-19-08: Neoadjuvant HER2-targeted Therapy +/- Immunotherapy with Pembrolizumab (neoHIP): An Open Label Randomized Phase II Trial

Abstract Background: Immune checkpoint inhibition (ICI) is synergistic with HER2-directed therapy in pre-clinical models. Clinically, pembrolizumab (K)-mediated ICI plus HER2-directed therapy with trastuzumab (H) was safe and demonstrated modest activity in H-resistant HER2-positive (HER2+) metastatic breast cancer. Because ICI may confer more robust activity when administered earlier in the course of disease, H and K administered in the curative-intent, treatment-naive setting may allow for de-escalation of cytotoxics; confer life-long, tumor-specific immunity; and ultimately, improve cure rates. Moreover, the synergy of H and K with paclitaxel (T) may overcome the need for dual HER2-blockade with H plus pertuzumab (P). In this randomized, multicenter, phase II, open-label trial the efficacy and safety of neoadjuvant THP vs THP-K vs TH-K are explored. Methods: Patients (pts) ≥18y with previously untreated, stage II-III, HER2+ breast cancer are being randomized and stratified by clinical nodal status (positive vs. negative) and hormone receptor status (positive vs. negative). In arm A, pts receive T at 80mg/m2 weekly for 12 weeks, H at 8mg/Kg (loading dose) and then 6mg/Kg every 3 weeks x 3 doses, P at 840 mg (loading dose) and then 420mg/Kg every 3 weeks x 3 doses (THP). In arm B, pts receive THP plus K at 200mg every 3 weeks x 4 doses (THP-K). In arm C, pts receive TH-K. After enrollment of 22 pts to arm C, a prespecified interim efficacy analysis was conducted, and enrollment to this arm was subsequently terminated. Enrollment to the other arms continues with 32/58 pts enrolled to arm A and 33/58 pts enrolled to arm B as of 2/14/2023. Definitive surgery is 3-6 weeks after the last dose. After surgery, pts are treated per the treating physician’s discretion per local clinical standard. The primary end point is pathologic complete response (pCR) rate in the breast and axilla (ypT0/Tis ypN0). Secondary end points include pCR rate by ypT0ypN0 and ypT0/Tis, residual cancer burden index, event free survival, breast conserving surgery rate, safety and overall survival. Exploratory correlative studies will characterize potential immune biomarkers predictive of efficacy and/or toxicity. Funding sources: BCRF, Merck NCT03747120 Citation Format: Heather McArthur, Jorge Henrique Santos Leal, Isaac Chan, Nisha Unni, Stephen Shiao, Joshua Gruber, Samira Syed, Namrata Peswani, Navid Sadeghi, Glenda Delgado, Dawn Klemow, Reva Basho, Meredith Carter, Mai Badran, Nasir Qureshi, Jessica Curtin, Joshua Weese, Stephanie Rice, Michelle Phillips, David Chan, Hugo Hool, Dorothy Park, Mary El-Masry, Philomena McAndrew, Swati Sikaria, Laura Spring, Aditya Bardia, Mourad Tighiouart, Farnaz Dadmanesh, Armando Giuliano, Katherine Sanchez, David Page. Neoadjuvant HER2-targeted Therapy +/- Immunotherapy with Pembrolizumab (neoHIP): An Open Label Randomized Phase II Trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-19-08.

Abstract PO1-27-01: Comparing the Efficacy and Safety of TQB2440 versus the Reference Pertuzumab for the Treatment of HER2-Positive Early or Locally Advanced Breast Cancer: A Multicenter, Randomized, Double-Blind, Parallel-Controlled Phase 3 Trial

Abstract Background: Pertuzumab is a recombinant humanized monoclonal antibody targeting the extracellular dimerization domain II of HER2. On September 30, 2013, the FDA have granted accelerated approval of a pertuzumab regimen for neoadjuvant treatment of patients (pts) with high-risk, HER2-positive early stage breast cancer. TQB2440 is a pertuzumab (Perjeta®, Roche) biosimilar. This study aimed to compare the efficacy and safety of TQB2440 and the reference pertuzumab combined with trastuzumab and docetaxel in pts with HER2-positive early or locally advanced breast cancer. Methods: In this multicenter, randomized, double-blind phase 3 study, eligible pts were aged 18-75 with operable HER2-positive (IHC 3+ or ISH+) clinical stage II-IIIC breast cancer negative for ER/PR and had an ECOG PS of 0-1. The pts were randomly assigned to receive either TQB2440 or the reference pertuzumab (Perjeta®) (840 mg on day 1, cycle 1, followed by 420 mg on cycle 2-4, q3w) added to trastuzumab (8 mg/kg on day 1, cycle 1, followed by 6 mg/kg for cycles 2-4, q3w) + docetaxel (75 mg/m2, cycle 1-4, q3w). The pts then underwent surgery followed by adjuvant treatment with FEC regimens (fluorouracil 600 mg/m², epirubicin 90 mg/m², cyclophosphamide 600 mg/m², cycle 5-7, q3w), then TQB2440 (840 mg on day 1, cycle 8, followed by 420 mg on cycle 9-20, q3w) + trastuzumab (8 mg/kg on day 1, cycle 8, followed by 6 mg/kg for cycles 9-20, q3w) or until disease progression or intolerable toxicity. The primary endpoint was total pathologic complete response (tpCR) by independent review committee (IRC). Equivalence was established if the 90% confdence intervals (CIs) of the relative ratio [RR] within the interval of 0.76 to 1.32. Secondary endpoints included breast pathologic complete response (bpCR) by IRC, tpCR &amp; bpCR by investigator, breast conserving surgery (BCS) rates, objective response rate (ORR), event-free survival (EFS), disease-free survival (DFS), OS and safety. Results: Between October 21, 2020, and November 21, 2022, 412 pts were enrolled (TQB2440 group, n=207; the reference pertuzumab group, n=205). Data cutoff was November 30, 2022. In the intention-to-treat (ITT) population, the tpCR by IRC of the TQB2440 group and the reference drug group were 58.94% and 58.05%, respectively. The RR was 1.02 (90% CI, 0.89, 1.16), which was within the predefined equivalence interval of 0.76 to 1.32. There was no statistically significant difference in the bpCR by IRC between the TQB2440 group and the reference pertuzumab group (67.63% [95% CI, 60.80%, 73.95%] vs. 63.90% [95% CI, 56.92%, 70.48%], P=0.4249). The BCS rate also comparable between the two groups with 13.04% (95% CI, 8.77%, 18.41%) vs. 13.17% (95% CI, 8.86%, 18.58%) (P=0.9695). Additionally, the results of the PP (per-protocol) population were similar to those of the ITT population. The incidence of treatment-related adverse events (TRAEs) and grade ≥3 TRAEs were similar between the TQB2440 group and the reference pertuzumab group with 79.71% vs. 75.98% and 49.28% vs. 41.67%, respectively. Conclusion: In patients with HER2-positive early or locally advanced breast cancer, TQB2440 demonstrated equivalent efficacy and similar safety to the reference pertuzumab. Clinical trial information: NCT05985187. Research Sponsor: Chia Tai Tianqing Pharmaceutical Group Co., Ltd Citation Format: Qingyuan Zhang, Shusen Wang, Nanlin Li, Qiao Cheng, Yu ren, Xuchen Cao, Jianjun Huang, Caigang Liu, Hongwei Yang, Limin Wei, Zhangjun Song, Huadong Zhao, Fangling Ning, Xiaojia Wang, Dehong Zou, Xiaohua Zeng, Jie Hao, Yunjiang Liu, Huijuan Wang, Nie Jianyun, Liang Li, Lina Liu, Tao Sun, Xiaobo Hu, Zhenhua Zhai, Huihua Xiong, Yuanqi Zhang, Enxiang Zhou, Jing Sun, Zhenhai Cai, Antai Zhang, Shui Wang, Junyang Mo, Qun Su, Xiuheng Qi, Guoren Zhou, Shuqun Zhang, Guozhong Cui, Wei Wang, Mingjiang Fan, Xinyu Qian, Xinhong Wu, Zhihong Wang, Jiuda Zhao, Yonghui Luo, Yanming Zhang, Fuguo Tian, Jiye Zhang, Dongning Chai, Qingshan Li. Comparing the Efficacy and Safety of TQB2440 versus the Reference Pertuzumab for the Treatment of HER2-Positive Early or Locally Advanced Breast Cancer: A Multicenter, Randomized, Double-Blind, Parallel-Controlled Phase 3 Trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-27-01.

Abstract PO1-14-12: Quantitative Biomarkers and 21-Gene Assay Results Predict Breast-Conserving Surgery Following Neoadjuvant Therapy in Early-Stage, Hormone Receptor-Positive, HER2-Negative Breast Cancer

Abstract Background: Neoadjuvant chemotherapy (NACT) and neoadjuvant endocrine therapy (NET) are often used to downstage tumors and/or enable breast-conserving surgery (BCS) in patients (pts) with early-stage, hormone receptor-positive/HER2-negative (HR+/HER2-) breast cancer. Given the increasing use of neoadjuvant therapy for HR+ breast cancer, studies are needed to better quantify the success of NACT/NET in downstaging tumors as a function of estrogen (ER), progesterone (PR), and Ki-67 expression, and 21-gene recurrence score (RS) in this patient population. Methods: Data were from pts with stage I-III, HR+/HER2- breast cancer diagnosed from 2010-2020 in the National Cancer Database (NCDB). Quantitative ER, PR, and Ki-67 data became available in 2018. We included pts who received either NACT or NET, with surgical plan categorized as mastectomy or BCS. Pts who received NACT for 12–30 weeks or NET for 4–36 months prior to surgery were eligible. Predicted rates of BCS by quantitative biomarkers (ER, PR, Ki-67 percentage, and RS) were estimated using restricted cubic spline logistic regression. Multivariable logistic regression models were fit to examine the associations between surgical plan and quantitative biomarkers for the two neoadjuvant cohorts. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were calculated per 10% increase in percentages of ER, PR, and Ki-67 expression. Results: Of 44,589 pts treated with NACT, the mean age was 53 years, the median amount of time they were on NACT before surgery was 21 weeks, and 65% had cT1-2 disease. Of 10,466 pts treated with NET, the mean age was 68 years, the median amount of time they were on NET before surgery was 6 months, and 76% had cT1-2 disease. Overall, 42% of pts underwent BCS after NACT; while 64% did after NET. In the NACT cohort, 13,752 of the pts with available quantitative biomarker data were included in regression analyses; in the NET cohort, 4,003 were included. After adjusting for demographic and clinicopathologic factors, increasing ER% (aOR=0.96, 95% CI: 0.94–0.97) and PR% (aOR=0.98, 95% CI: 0.96–0.99) were associated with lower odds of BCS after NACT. Increasing Ki-67% was associated with greater odds of BCS after NACT (aOR=1.07, 95% CI: 1.04–1.10). Pts with a low (aOR=0.50, 95% CI: 0.29–0.88) or intermediate (aOR=0.58, 95% CI: 0.41–0.81) RS were significantly less likely than pts with a high RS to undergo BCS after NACT. Asian pts were less likely than White pts to have BCS (aOR=0.75, 95% CI: 0.56–0.99), while rates of BCS after NACT were similar to pts from other racial and ethnic groups. In the NET cohort, increasing ER% was associated with greater odds of BCS (aOR=1.09, 95% CI: 1.01–1.17). There was no significant association between baseline PR% or Ki-67% and BCS after NET. Pts with a low (aOR=0.92, 95% CI: 0.60–1.43) or intermediate (aOR=0.96, 95% CI: 0.65–1.41) RS were numerically less likely than pts with a high RS to have BCS after NET, though not statistically significant. Compared with White pts, Asian pts were less likely to have BCS after NET (aOR=0.60, 95% CI: 0.40–0.91). Conclusions: In this analysis of pts from the NCDB who received neoadjuvant therapy for early-stage, HR+/HER2- breast cancer, we found that BCS after NACT was higher for patients with a high RS or high Ki-67, suggesting that NACT is unlikely to downstage tumors with a low/intermediate RS or low Ki-67. Most pts receiving NET underwent BCS (likely due to a smaller clinical tumor size); BCT after NET was most dependent on ER expression. Asian pts were less likely to undergo BCS after either NACT or NET, which is consistent with previous reports. These data could facilitate appropriate neoadjuvant treatment selection based on tumor biology and improve patient counseling on the likelihood of successful BCS. Citation Format: Jincong Freeman, Sarah Shubeck, Nan Chen, Rita Nanda, Dezheng Huo, Frederick Howard. Quantitative Biomarkers and 21-Gene Assay Results Predict Breast-Conserving Surgery Following Neoadjuvant Therapy in Early-Stage, Hormone Receptor-Positive, HER2-Negative Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-14-12.

Abstract PO2-23-05: Practice patterns and outcomes in the ongoing neoadjuvant ATNEC trial: node marking, response to NACT and breast conservation rates

Abstract Background In ATNEC trial, cT1-3N1M0 patients receive NACT followed by SNB/TAD. If the sentinel nodes(SNs) have converted to benign(ypN0), patients are randomly assigned to Axillary Treatment vs no Axillary Treatment. The study promotes standardized node marking procedures and includes a radiotherapy quality assurance program. Objectives – This study prospectively evaluates practice patterns, NACT response, adoption of node marking, rates of marked node identification, and breast conservation rates in the ongoing ATNEC trial across 70 centers in the UK. The trial aims to recruit 1900 patients. Materials and Methods Data from 196 randomized patients (median age: 54 [range: 28-79] years; median BMI: 26.5 [range: 17.6-51.1]) from December 2021 to June 28, 2023, across 70 UK centers were analyzed. These patients presented with cT1-3N1M0 breast cancer, received NACT, and exhibited no residual nodal disease (ypN0) on SNB/TAD. Results Among the randomised patients 54%(106) were post-menopausal, 71%(140) underwent breast conserving surgery(BCS) and 29%(56) mastectomy. At presentation, 12% (23) had T3, 63% (124) had T2, and 23% (46) had T1 tumors. Grade 3 tumors accounted for 70% (138) of cases. Among the patients, 60% (117) were HER2 positive, 31% (61) were triple negative, and 9% (18) were HER2 negative (ER or PgR positive). Anthracycline and taxane-based NACT were administered to 57% (106), while 38% (71) received a platinum-containing regimen. During SNB/TAD, a median of 4 nodes (interquartile range, 3-5) were removed. Among 184 patients with node marking data, 74% (136) had the involved node marked. The marked node was successfully removed in 94% (128) of these patients. Clip/coil only, Magseed and black dye were the commonest techniques used for node marking. The marked node was the sentinel node in 83% (106) of cases. Among 185 randomized patients with post-NACT response data, 68% (125) achieved a complete pathological response (pCR) in the breast, while 8% (15) had DCIS only and 22% (41) had invasive cancer. Among 105 patients with complete breast tumor response on imaging, 15% (16) had residual DCIS or invasive cancer. In the subset of patients with partial response or stable breast tumors on imaging (69 patients), 46% (32) had no residual tumor on histology (ypT0). Furthermore, 14% (26) exhibited partial or stable disease in the axilla on imaging but achieved complete pathological response on histology. Conclusions HER2-positive and triple-negative breast cancer cases predominate among patients undergoing NACT in the UK. Although 68% achieved a complete pCR (ypT0) in the breast, rates of BCS remain low. Notably, around 75% of randomized patients underwent node marking, with an intra-operative identification rate of 94%, demonstrating the successful implementation of node marking in the UK through the ATNEC trial. Citation Format: Amit Goyal, Andrea Marshall, Sophie Nicholls, Natalie Hammonds, Beatrix Elsberger, Duncan Wheatley, Janice Rose, Helen-Teresa Edwards, Abeer Shaaban, Roeum Butt, Gareth Jackson, Tara Homer, Luke Vale, Samreen Ahmed, Shama Puri, Sophie Gasson, Julie Bruce, Helen Higgins, Janet Dunn. Practice patterns and outcomes in the ongoing neoadjuvant ATNEC trial: node marking, response to NACT and breast conservation rates [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-23-05.

The impact of advanced oncoplastic surgery on breast-conserving surgery rates: A retrospective cohort study of 4,000 breast cancer procedures at a tertiary referral centre

The impact of advanced oncoplastic surgery on breast-conserving surgery rates: A retrospective cohort study of 4,000 breast cancer procedures at a tertiary referral centre

Immigration Status and Breast Cancer Surgery Quality of Care Metrics: A Population-Level Analysis.

As immigrant women face challenges accessing health care, we hypothesized that immigration status would be associated with fewer women with breast cancer receiving surgery for curable disease, fewer undergoing breast conserving surgery (BCS), and longer wait time to surgery. A population-level retrospective cohort study, including women aged 18-70 years with Stage I-III breast cancer diagnosed between 2010 and 2016 in Ontario was conducted. Multivariable analysis was performed to assess odds of undergoing surgery, receiving BCS and wait time to surgery. A total of 31,755 patients were included [26,253 (82.7%) Canadian-born and 5502 (17.3%) immigrant women]. Immigrant women were younger (mean age 51.6 vs. 56.1 years) and less often presented with Stage I/II disease (87.4% vs. 89.8%) (both p < .001). On multivariable analysis, there was no difference between immigrant women and Canadian-born women in odds of undergoing surgery [Stage I OR 0.93 (95% CI 0.79-1.11), Stage II 1.04 (0.89-1.22), Stage III 1.22 (0.94-1.57)], receiving BCS [Stage I 0.93 (0.82-1.05), Stage II 0.96 (0.86-1.07), Stage III 1.00 (0.83-1.22)], or wait time [Stage I 0.45 (-0.61-1.50), Stage II 0.33 (-0.86-1.52), Stage III 3.03 (-0.05-6.12)]. In exploratory analysis, new immigrants did not have surgery more than established immigrants (12.9% vs. 10.1%), and refugee women had longer wait time compared with economic-class immigrants (39.5 vs. 35.3 days). We observed differences in measures of socioeconomic disadvantage and disease characteristics between immigrant and Canadian-born women with breast cancer. Upon adjusting for these factors, no differences emerged in rate of surgery, rate of BCS, and time to surgery. The lack of disparity suggests barriers to accessing basic components of breast cancer care may be mitigated by the universal healthcare system in Canada.

Cytomorphological Disparities in Invasive Breast Cancer Cells following Neoadjuvant Endocrine Therapy and Chemotherapy

Introduction: Neoadjuvant endocrine therapy (NAE) offers a breast-conserving surgery rate and clinical response rate similar to those of neoadjuvant chemotherapy (NAC), while presenting fewer adverse events and lower pathological complete response rates. The assessment of pathological response determines degenerative changes and predicts the prognosis of breast cancer treated with NAC. This study clarified the degenerative changes occurring in breast cancer following NAE. Methods: Our study encompassed two groups: NAE, consisting of 15 patients, and NAC, comprising 18 patients. Tissue samples were obtained from core needle biopsies and surgeries. Nuclear and cell areas were calculated using Autocell analysis. Furthermore, we assessed markers associated with microtubule depolymerization (KIF2A) and initiators of apoptosis (caspase-9). Results: In the NAC group, we observed significant increases in both cytoplasmic and cell areas. These changes in cytoplasm and cells were notably more pronounced in the NAC group compared to the NAE group. After treatment, KIF2A exhibited a decrease, with the magnitude of change being greater in the NET group than in the NAC group. However, no discernible differences were found in caspase-9 expression between the two groups. Conclusion: Our findings indicate that NAE induces condensation in cancer cells via cell cycle arrest or apoptosis. Conversely, NAC leads to cell enlargement due to the absence of microtubule depolymerization. These discrepancies underscore the importance of accounting for these distinctions when establishing criteria for evaluating pathological responses.

207 (PB-114) Poster - The impact of advanced oncoplastic surgery on breast-conserving surgery rates: a retrospective study of 4,500 breast cancer procedures at a tertiary referral centre

207 (PB-114) Poster - The impact of advanced oncoplastic surgery on breast-conserving surgery rates: a retrospective study of 4,500 breast cancer procedures at a tertiary referral centre