Locally Advanced Breast Cancer Research Articles

Effect of neoadjuvant chemotherapy on the expression of hormone receptors and Ki-67 in patients with locally advanced breast cancer

Background: Neoadjuvant chemotherapy (NACT) affects the tumor protein marker’s expression and status. Changes in the expression of biomarkers during NACT may influence the clinical decision of adjuvant molecular and hormonal therapy. Hence, re-evaluation of receptor status has to be done after NACT to give a specific adjuvant therapy for patient benefit. Aims and Objectives: The aim of this study was to study the status of hormone receptors (HRs) – estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (Her-2/Neu), and Ki-67 in patients with locally advanced breast cancer (LABC) in both core needle biopsies and post-mastectomy specimens after administering neoadjuvant chemotherapy. Materials and Methods: The present study was conducted in the Department of Pathology in collaboration with the Department of Surgery, Pt B D Sharma PGIMS, Rohtak, for a period of 1 year. The study comprised 52 patients with LABC who received neoadjuvant chemotherapy and 20 control cases who did not receive neoadjuvant chemotherapy. Each case comprised two specimens: Trucut biopsy and a mastectomy specimen. Results: ER changed from positive to negative in 15.4% of the cases and from negative to positive in 1.9% of the cases. The overall change in ER was statistically significant (P=0.020). For PR, 9.6% of the cases changed from positive to negative while none of the cases showed change from negative to positive. The overall change in PR was statistically significant (P=0.025). For HER2/Neu, 19.2% of the cases changed from positive to negative, and 11.5% of the cases changed from negative to positive. The overall change in HER2/Neu was not statistically significant (P=0.317). For Ki-67, 30% of patients changed from positive to negative while 11.5% of patients changed from negative to positive. The overall change in Ki-67 was statistically significant (P=0.024). Conclusion: There was discordance in the HR status and proliferation marker after NACT in patients with breast cancer. The administration of NACT might be the main reason for the change in receptor status thus understanding the chemotherapy-induced biological conversion in the tumor cell behavior is strategically important in planning adjuvant endocrine therapy and for disease follow-up.

Effect of Interval Between Neoadjuvant Chemotherapy and Surgery on Oncological Outcomes in Poor Responders With Locally Advanced Breast Cancer.

The interval between neoadjuvant chemotherapy (NAC) and surgery for locally advanced breast cancer (LABC) remains controversial. At the same time, the prognostic effect of delayed surgery in patients with poor responses is currently unclear. Data was collected from patients who had poor responses to NAC and underwent modified radical surgery from January 2013 to December 2018. The interval from completion of NAC to surgery was divided into two groups: a longer (greater than four weeks) or shorter (four weeks or less) interval. The associations of these interval groups with overall survival (OS) and recurrence-free survival (RFS) were evaluated by multivariable Cox models adjusting for the existing prognostic factors. Propensity score matching (PSM) was used to minimize election bias. A total of 1,229 patients (mean age, 47.2 ± 8.9 years; median follow-up duration, 32.67 [6.57-52.63] months) were included. The 5-year OS rates were 73.2% and 60.8% in the shorter (n = 171) and longer interval group (n = 1,058), respectively, while the 3-year RFS rates were 80.8% and 71.7%, respectively. In multivariate Cox analysis, the longer interval was associated with an increased risk of mortality (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.01-2.02; p = 0.046) and recurrence (HR, 1.50; 95% CI, 1.12-1.99; p = 0.006). There was an interaction between the molecular subtype and the surgery interval for OS (pinteraction = 0.014) and RFS (pinteraction = 0.027). After PSM, no significant difference in OS (p = 0.180) and RFS (p = 0.069) was observed between the two groups. Among LABC patients with a poor response, those with a longer interval between NAC and surgery had worse OS and RFS. The results indicate that these patients should receive modified radical surgery timely, which may in turn improve their prognosis.

Neoadjuvant inetetamab and pertuzumab with taxanes and carboplatin (TCbIP) In locally advanced HER2-positive breast cancer: a prospective cohort study with propensity-matched analysis

BackgroundInetetamab is the first domestically developed innovative anti-HER2 monoclonal antibody in China, proven effective and safe in HER2-positive advanced breast cancer. However, its efficacy and safety in neoadjuvant treatment of HER2-positive locally advanced breast cancer (LABC) remain to be validated.MethodsThis prospective cohort study aimed to evaluate the efficacy and safety of inetetamab combined with pertuzumab, taxanes, and carboplatin (TCbIP) in neoadjuvant therapy for HER2-positive LABC, comparing it to data from patients treated with the TCbHP regimen (trastuzumab combined with pertuzumab, taxanes, and carboplatin) using propensity score matching (PSM). The primary endpoint was total pathological complete response (tpCR). Adverse events (AEs), objective response rate (ORR), and near-pCR were key secondary endpoints.ResultsForty-four patients with clinical stage IIA-IIIC HER2-positive LABC were prospectively enrolled and treated with the TCbIP regimen. The tpCR rate among 28 patients who completed surgery was 60.7%, comparable to and slightly higher than the TCbHP group in PSM (60.7% vs. 53.6%, P = 0.510). The ORR was 96.4%, and the DCR reached 100.0%. The most common ≥ grade 3 AE was neutropenia (21.4% vs. 11.9%, P = 0.350). No significant reduction in left ventricular ejection fraction was observed, and no patient withdrew from treatment due to AEs.ConclusionNeoadjuvant therapy with TCbIP showed good efficacy and safety in patients with HER2-positive LABC and might be another promising option for neoadjuvant treatment.Trial registrationNCT05749016 (registration date: Nov 01, 2021).

A Single-Arm Phase II Clinical Trial of Fulvestrant Combined with Neoadjuvant Chemotherapy of ER+/HER2- Locally Advanced Breast Cancer: Integrated Analysis of 18F-FES PET-CT and Metabolites with Treatment Response.

This Phase II trial was objected to evaluate the efficacy and safety of adding fulvestrant to NCT in patients with ER+/HER2- locally advanced breast cancer (LABC). Additionally, the study aimed to investigate the association of 18F-FES PET-CT and metabolites with efficacy. Fulvestrant and EC-T regimen were given to ER+/HER2- LABC patients before surgery. At baseline, patients received 18F-FES PET-CT scan, and plasma samples were taken for LC-MS analysis. The primary endpoint was ORR. Secondary endpoints included tpCR and safety. Among the 36 patients enrolled, the ORR was 86.1%, the tpCR rate was 8.3%. The incidence of grade ≥3 TEAEs was 22%. The decrease in ER value in sensitive patients was larger than that in non-sensitive patients, as was Ki-67 (p<0.05). The SUVmax, SUVmean, TL-ER of 18F-FES PET-CT in sensitive patients were significantly higher than those in non-sensitive patients (p<0.05). Moreover, these parameters were significantly correlated with MP grade and the change in ER expression before and after treatment (p<0.05). Thirteen differential expressed metabolites were identified, which were markedly enriched in 19 metabolic pathways. This regimen demonstrated acceptable toxicity and encouraging antitumor efficacy. 18F-FES PET-CT might serve as a tool to predict the effectiveness of this therapy. Altered metabolites or metabolic pathways might be associated with treatment response.

ER-Targeted PET for Initial Staging and Suspected Recurrence in ER-Positive Breast Cancer

There are insufficient data comparing 16α-18F-fluoro-17β-estradiol (FES) positron emission tomography (PET) computed tomography (CT) with standard-of-care imaging (SOC) for staging locally advanced breast cancer (LABC) or evaluating suspected recurrence. To determine the detection rate of FES PET/CT and SOC for distant metastases in patients with estrogen receptor (ER)-positive LABC and recurrences in patients with ER-positive BC and suspected recurrence. This diagnostic study was conducted as a single-center phase 2 trial, from January 2021 to September 2023. The study design provided 80% power to find a 20% detection rate difference. Participants included patients with ER-positive LABC (cohort 1) or suspected recurrence (cohort 2). Data were analyzed from September 2023 to February 2024. Participants underwent both SOC imaging and experimental FES PET/CT. When there were suspicious lesions on imaging, 1 was biopsied for histopathological reference standard to confirm presence (true positive) or absence (false positive) of malignant neoplasm. The outcome of interest was the detection rate of FES PET CT vs SOC for distant metastases and recurrences. A total of 124 patients were accrued, with 62 in cohort 1 (median [IQR] age, 52 [32-84] years) and 62 in cohort 2 (median [IQR] age, 66 [30-93] years). In cohort 1, of 14 true-positive findings, SOC imaging detected 12 and FES detected 11 (P > .99). In cohort 2, of 23 true-positive findings, SOC detected 16 and FES detected 18 (P = .77). In 30 patients with lobular histology, of 11 true-positive findings, SOC detected 5 and FES detected 9 (P = .29). There were 6 false-positive findings on SOC and 1 false-positive finding on FES PET/CT (P = .13). In this diagnostic study with pathological findings as the reference standard, no difference was found between FES PET/CT and current SOC imaging for detecting distant metastases in patients with ER-positive LABC or recurrences in patients with ER-positive tumors and suspected recurrence. FES PET/CT could be considered for both clinical indications, which are not part of current Appropriate Use Criteria for FES PET. The findings regarding FES PET/CT in patients with lobular tumors, and for lower false positives than current SOC imaging, warrant further investigation.

Clinicopathological Profiles of and Patterns of Recurrence in Triple-Negative Breast Cancer Patients at a Cancer Care Center in Southern India.

Triple-negative breast cancer (TNBC) is characterized by the absence of expression of the estrogen receptor and the progesterone receptor by immunohistochemistry and human epidermal growth factor receptor overexpression absence either by immunohistochemistry or absence of amplification by fluorescence in-situ hybridization. TNBCs tend to have rapid growth when compared to other subtypes of breast cancer. TNBC is associated with higher histologic grade and more advanced disease at presentation. TNBC shows aggressive behavior and a high chance of recurrence. The aim was to analyze the clinicopathological profiles of and recurrence patterns in TNBC patients at our institute where most patients are from rural areas. This retrospective study was done at a tertiary cancer care center in Southern India where most patients come from rural backgrounds. Institutional Ethics Committee approval was obtained before the study. Case files of all breast cancer patients registered and treated at our center from 2014 to 2019 were retrieved from the medical record department and reviewed. Data from patients diagnosed with triple-negative breast cancer were identified and analyzed. Among the 841 breast cancer patients registered in our study, 150 (17.8%) were diagnosed with TNBC. The median age of diagnosis was 47 years. The majority of the patients, 89 (59.3%) presented with T2 tumors, and lymph node involvement was observed in 88 (58.6%) cases. Patient distribution based on cancer stage revealed that 77 (51.3%) had early-stage breast cancer (EBC), 70 (46.6%) had locally advanced breast cancer (LABC), and only three patients were categorized as having metastatic breast cancer (MBC). Modified radical mastectomy (MRM) was the preferred surgical approach in 144 (96%) cases, while only four patients underwent breast-conserving surgery (BCS). Adjuvant chemotherapy was administered to 119 (79.3%) patients, with 30 (20%) receiving both neoadjuvant and adjuvant chemotherapy (NACT/ACT). Among those who underwent NACT/ACT, a pathological complete response was observed in five (16.6%) patients out of 30 patients. The median duration of follow-up was 32.8 months. Among all patients, 36 (24%) experienced recurrence, with seven (19.4%) having local recurrence, 24 (66.6%) developing distant metastases, two patients experiencing both local and distant recurrence, and three patients developing contralateral breast cancer. Additionally, three patients experienced a second primary cancer. The most common sites of metastases were the lungs (14), followed by the bone (seven), the liver (four), and the brain (four). Recurrence rates were notably high within the first one to three years post-diagnosis. The median disease-free survival (DFS) of TNBC patients was estimated to be 65.6 months with no statistically significant difference (p=0.174) between EBC and LABC patients. TNBC is known for its heterogeneity. While it is often regarded as being more responsive to chemotherapy compared to other subtypes of breast cancer, TNBCs tend to behave aggressively, basically due to the underlying aggressive tumor biology. Though there are many treatment options for different subtypes of breast cancer, therapeutic modalities are limited for TNBCs. Aggressive tumor biology with limited treatment options denotes a gap in the development of novel strategies to improve outcomes in this subset of breast cancer patients.

Establishment of a logistic regression model nomogram for clinicopathological characteristics and risk factors with axillary lymph node metastasis in T1 locally advanced breast cancer: a retrospective study.

Although the research reports on locally advanced breast cancer (LABC) are increasing year by year, there are few reports on T1 LABC axillary lymph node metastasis (ALNM). By establishing a prediction model for T1 LABC ALNM, this study provides a reference value for the probability of ALNM of related patients, which helps clinicians to develop a more effective and individualized treatment plan for LABC. Cases with pathologically confirmed T1 breast cancer (BC) between 2010 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were identified. Logistic regression was used to analyze the correlation between LABC lymph node metastasis and every factor, and the odds ratio (OR) and 95% confidence interval (CI) were used to identify any influencing factors. A nomogram was drawn after incorporating meaningful factors identified in multivariate logistic regression into the model. The receiver operating characteristic (ROC) curve of the model was drawn, and the area under the curve (AUC) and its 95% CI were calculated. Hosmer-Lemeshow goodness-of-fit test and clinical decision curve analysis (DCA) were performed. The results were validated in the validation group. A total of 200,933 female T1 BC patients were included in this study. Univariate and multivariate logistic regression analysis of T1 BC showed that progesterone receptor (PR)-negative, race, age, lobular carcinoma, micropapillary ductal carcinoma, axillary tail tumor, poor differentiation, and larger tumor diameter increased the probability of ALNM in T1 LABC. A predictive nomogram was established using the above predictors, the AUC of the modeling group was 0.739 (95% CI: 0.732-0.747), and when the AUC cut-off value was 0.026, the specificity and sensitivity of the model were 65.78% and 69.99%, respectively. Validation of the model showed that the AUC of the validation group (n=60,280) was 0.741. When all the risk factors were met, the predicted probability of N2-N3 was 50.40%. In this study, it was found that PR-negative, Black race, age, lobular carcinoma, micropapillary ductal carcinoma, axillary tail tumor, poor differentiation, and tumor diameter increased the probability of large lymph node metastasis in T1 LABC small tumors.

Optimal neoadjuvant treatment and prognostic factors in patients with HR-positive/HER2-positive early or locally advanced breast cancer: A national real-world study in China.

e12514 Background: Few data have been reported regarding breast cancer (BC) population characterized by HR+/HER2+ especially in a real-world setting in China. This analysis aimed at identifying differences in short-term treatment outcomes of different neoadjuvant therapy (NAT) regimens, effects of the demographics and clinical features on short-term outcomes of NAT, and further understanding the prognostic factors related to those outcomes in HR+/HER2+ early (EBC) or locally advanced BC (LABC) pts by using dataset from National Cancer Information Database (NCID) in China. Methods: This retrospective, multicenter, real-world study used electronic medical record data from NCID. We analyzed HR+/HER2+ EBC or LABC Chinese pts who were initially diagnosed between Jan 1, 2019 and May 31, 2022 and received NAT followed by surgery during study period. Primary endpoints included total pathological complete response (tpCR) and breast pCR (bpCR). Secondary endpoints included disease-free survival (DFS) and event-free survival (EFS). Results: 3792 pts from NCID covering 51 hospitals, 26 provinces met inclusion criteria and were included. After controlling for age and post-surgery N staging, 1-, 2- and 3-yr DFS was similar between trastuzumab (T) and T+pertuzumab (P) NAT subgroup (92.79%, 87.20% and 83.32% vs 94.83%, 88.82% and 87.88%; p=0.1120). 1-, 2- and 3-yr EFS was higher in T+P subgroup (T vs T+P: 85.24%, 82.35%, 77.01% vs 90.86%, 89.65%, 82.78%; p = 0.0003). Logistic regression multivariate analysis showed improved tpCR and bpCR was independently positively associated with receiving T+P NAT (vs T: both p &lt; 0.0001), platinum NAT (vs anthracycline: p = 0.0071 and 0.0122, resp.), while negatively associated with receiving no targeted therapy (vs T: p = 0.0002 and &lt; 0.0001, resp.), ≥ 65 yrs (vs &gt; 40 yrs, &lt; 64 yrs: p = 0.0116 and 0.0290, resp.), or post-surgery ER positive (vs negative: both p &lt; 0.0001). Conclusions: HR+/HER2+ EBC or LABC gained short- and long-term benefit from HER2 dual-blockade therapy in clinical practice. Prognostic factors for improved tpCR and bpCR included T+P and platinum NAT, whereas ≥ 65 yrs and post-surgery ER+ were predictive of decreased tpCR and bpCR. [Table: see text]

A propensity-matched analysis of the efficacy and safety of neoadjuvant inetetamab and pertuzumab with paclitaxel and carboplatin (TCbIP) on locally advanced HER2-positive breast cancer.

e12609 Background: Inetetamab is an Fc segment-modified innovative anti-HER2 monoclonal antibody. It has been proven to be effective and safe in HER2-positive advanced breast cancer. However, its efficacy and safety in the neoadjuvant treatment of HER2-positive locally advanced breast cancer (LABC) remains to be validated. This study aimed to evaluate the efficacy and safety of Inetetamab-based neoadjuvant therapy (TCbIP). Methods: In this prospective cohort study, we investigated the efficacy and safety of TCbIP in neoadjuvant therapy for HER2-positive LABC, and compared with TCbHP regimen (trastuzumab combined with pertuzumab, paclitaxel, and carboplatin) with propensity score matching (PSM). Thirty-four patients (clinical stage IIA-IIIC, HER2-positive LABC) were prospectively enrolled in this study and treated with the TCbIP regimen. The primary endpoint was total pathological complete response (tpCR). Adverse events (AEs), objective response rate (ORR), and near-pCR were key secondary endpoints. Results: The pCR rate of 28 patients who finished surgery was 60.7%, and was comparable and slightly higher (60.7% vs. 53.6%, P = 0.510) than the TCbHP group in PSM. The ORR was 96.4% and DCR reached 100.0%. The most common ≥grade 3 AE was neutropenia (21.4% vs. 11.9%, P = 0.350). No significant reduction in left ventricular ejection fraction was observed, and no patient withdrew from treatment due to AEs. Conclusions: Neoadjuvant therapy with TCbIP resulted in good efficacy and safety in patients with HER2-positive LABC, and might be another promising option for neoadjuvant treatment. Clinical trial information: NCT05749016 .

Clinical and Pathologic Tumor Response Following Response-guided Neoadjuvant Chemotherapy for Locally-advanced Breast Cancer in a Tertiary Hospital Breast Center in the Philippines

Clinical and Pathologic Tumor Response Following Response-guided Neoadjuvant Chemotherapy for Locally-advanced Breast Cancer in a Tertiary Hospital Breast Center in the Philippines

Trastuzumab-emtansine versus other anti-HER2 regimens in early or unresectable or metastatic HER-2 positive breast cancer: systematic review and network meta-analysis.

Motivation for the study. Treatment options for HER2-positive breast cancer were evaluated, focusing on the efficacy and safety of trastuzumab-emtansine (T-DM1) compared to other anti-HER2 therapies. Main findings. Trastuzumab-deruxtecan (T-DXd) and PyroCap emerged as promising alternatives, showing substantial improvements in progression-free survival for locally advanced or metastatic breast cancer. T-DM1 showed superior efficacy to the other treatments. Implications. Our findings could inform healthcare decision-making processes to optimize strategies for HER2-positive breast cancer, and potentially improve health outcomes and quality of life. We aimed to study the efficacy and safety of trastuzumab-emtansine (T-DM1) versus other anti-HER2 therapies in HER2+ breast cancer (BC). We performed a network meta-analysis (NMA) of randomized controlled trials (RCTs). Our study focused on patients undergoing treatment for unresectable locally advanced breast cancer (LABC) or metastatic breast cancer (mBC), which included regimens involving trastuzumab and taxanes. Additionally, we considered cases within the first 6 months of treatment for HER2+ early breast cancer (EBC). A total of 23 RCTs and 41 reports were included in our analysis. LABC and mBC showed no statistically significant difference in any of the comparisons of T-DM1 versus the other anti-HER2+ therapies. When assessing progression-free survival (PFS), trastuzumab-deruxtecan (T-DXd) and PyroCap demonstrated greater efficacy compared to other treatments (Hazard Ratio [HR]: 3.57; 95% confidence interval [CI]: 2.75-4.63 and HR: 1.82; 95% CI: 1.35-2.44; respectively), while T-DM1 alone exhibited superior effectiveness compared to LapCap (HR: 0.65; 95% CI: 0.55-0.77), TrasCap (HR: 0.65; 95% CI: 0.46-0.91), LapCapCitu (HR: 0.60; 95% CI: 0.33-1.10), Nera (HR: 0.55; 95% CI: 0.39-0.77), and Cap (HR: 0.37; 95% CI: 0.28-0.49). NMA allows a ranking based on the comparative efficacy and safety among the interventions available. Although superior to other schemes, T-DM1 showed a lower efficacy performance in PFS and overall response rate and a trend towards worse overall survival than T-DXd.

Survival and inferential analysis in patients with locally advanced breast cancer treated with neoadjuvant chemotherapy and subsequent sentinel lymph node biopsy: prospective single-center study

BackgroundThe lymph node staging is the major prognostic factor in breast cancer patients. Sentinel lymph node biopsy (SLNB) allows an exactly axillar staging in patients with early disease, but not in locally advance breast cancer (LABC). Our aim was to study, the feasibility and accuracy of the SLNB technique with and without axillar lymphadenectomy (LDN) and with lymph node clipping after neoadjuvant chemotherapy (NAC), in patients with LABC.Patients and methodsPatients diagnosed with LABC, scheduled for NAC and subsequent surgery and SLNB. Subsequently the patients were scheduled for adjuvant chemotherapy/hormonotherapy and radiotherapy according with the postsurgical results. Main end points were overall survival (OS) disease-free survival (DFS), mortality, SLNB identification rate (IR), sensitivity, false negative rate (FNR) of SLNB versus LDN, negative predictive value (NPV) and overall accuracy.ResultsOur IR with different techniques was between 89.9 and 100%. OS was between 89 and 97%. DFS was between 89.8 and 96.8%. Sensitivity was between 75 and 100%. NPV was between 89.6 and 100%. FNR was between 0 and 25%; and accuracy was between 66 and 72%. We found that survival was lower (p < 0.05) in patients with triple negative and Luminal B/HER2 intrinsic subtype; with progression or major partial response in Magnetic Resonance Imaging (MRI) results at the end of NAC and in patients with BRCA1/2 mutation.ConclusionsOur study presents excellent results of SLNB alone in patients with LABC with complete nodal response with an OS and DFS > 95%. The FNR is very high in partial responders, so we cannot recommend the SLNB alone in LABC. We recommend, in cN+ patients, axillar clipping, SLNB and LDN because in more than 50% of the patients with axillar clipping, this was not found, and because in 36% of the patients with negative LDN, the SLN (Sentinel Lymph Node) obtained was the only positive node, so these techniques together decrease the FNR and improve the node staging, OS and DFS. This study is the first prospective study that assess OS and DFS in patients with LABC, all submitted to SLNB.

Breast Conserving Surgery Post Neo-Adjuvant Chemotherapy for Locally Advanced Breast Carcinoma in a Developing Country: Is It Safe?

Breast conserving surgery (BCS) is the standard treatment for early breast cancer and has similar survival with mastectomy. The role of BCS in locally advanced breast cancer (LABC), post neoadjuvant chemotherapy (NACT), is controversial. Surgeons, especially in developing countries, fear higher margin involvement and local recurrence (LR) in BCS. The aim of this study was to determine the LR in BCS compared to mastectomy in LABC post NACT and to ascertain the percentage of involved surgical margins following both methods of surgery. This was a retrospective study of breast cancer patients seen in Universiti Kebangsaan Malaysia Medical Centre (UKMMC). All patients had NACT followed by either mastectomy or BCS. The patients with Her2 enriched carcinomas did not have access to targeted therapy (Trastuzumab or Pertuzumab). The patients with ill-defined tumours underwent ultrasound assessment in the surgical clinics. All had post-operative radiotherapy. All with ER or PR positive cancers were given Tamoxifen for a minimum of 5 years. This study demonstrated that BCS post NACT was safe to be performed in selected patients with LABC in a developing country.

Abstract PO3-05-13: A Multi-Institutional Review of Contralateral Axillary Metastases: Time for Reclassification as Local-Regional Event?

Abstract Background Current American Joint Committee on Cancer (AJCC) breast cancer staging considers contralateral axillary metastasis (CAM) stage IV disease (M1). Retrospective studies suggest that women with CAM have improved overall survival (OS) compared to those with distant metastasis (M1) and/or comparable OS to locally advanced breast cancer (LABC). These studies support consideration of curative intent treatment; however, they contain heterogeneous cohorts with highly variable treatment strategies. We sought to evaluate treatment and outcomes in a well-defined CAM cohort treated with contemporary systemic and locoregional therapy. Methods We performed a retrospective multi-institution cohort study to compare OS of patients with CAM matched 1:3 on age +/- 5 years to LABC (defined as cN2-3 and/or pN2-3), and to non-CAM M1. CAM patients classified as type 1) de novo CAM, synchronous with the contralateral primary, 2) metachronous isolated CAM in the setting of prior surgical and/or radiation treatment to primary index cancer, 3) synchronous with, or 4) metachronous after an in-breast or axillary nodal recurrence of the primary index cancer. The M1 cohort included de novo and recurrent metastasis with varied sites and number of metastasis. OS was defined as time from CAM diagnosis to death or last follow-up for CAM patients; time from primary diagnosis to death or last follow-up for LABC; and time from metastatic diagnosis to death or last follow-up for M1. Unadjusted OS was estimated with the Kaplan-Meier method, and Cox proportional hazards models were used to estimate the association of group with OS after adjustment for covariates Results We identified 57 CAM and 155 LABC from 8 institutions (2016-2022), and 632 M1 from a single institution. The median age was similar between groups (CAM=59 years, LABC=58, M1=57, p=0.44), and there were no statistically significant differences in hormone receptor status (p=0.25). There were more Non-Hispanic Black patients in the M1 cohort compared to CAM or LABC (p&amp;lt; 0.001). The majority of CAM cases were delayed metachronous from the index cancer (type 2, 35.1%), or synchronous with a recurrence (type 3, 33.3%). Type 1 (de novo, 14%) and type 4 (delayed metachronous after breast cancer recurrence, 17.5%) were less frequent. Among CAM patients, 49.1% were hormone receptor positive (HR+)/HER2-negative (HER2-), 22.8% HR-/HER2-, 10.5% HR+/HER2+, and 5.3% HR-/HER2+. Comparing CAM versus LABC, invasive ductal carcinoma (IDC) was more commonly seen in CAM (82.5% vs 66.5%), as was grade 3 (45.6% vs 35.5%), and triple negative (22.8% vs 13.5%). Conversely, in LABC, treatment of the primary index cancer more frequently included chemotherapy (CAM=71.9%, LABC=92.3%), mastectomy (CAM=54.4%, LABC 74.2%), and adjuvant radiation (CAM=73.7%, LABC=90.3%). On multivariable analysis adjusting for age, race/ethnicity, and hormone receptor status, both CAM and M1 had inferior survival to LABC (Table 1), but with a 2.4-fold difference for CAM (95% CI 1.42-4.07, p=0.001) versus a 6.3-fold difference for M1 (95% CI 4.29-9.23, p=&amp;lt; 0.001). Discussion In this contemporary, multi-institution study, we demonstrated that CAM patients selected for presumed curative intent treatment experienced improved OS when compared to stage IV (M1) patients. Our data adds additional support for re-evaluating the current stage IV designation, in favor of N3, and consideration of curative intent treatment in this disease. Table. Adjusted* Overall Survival Comparing Patients with Breast Cancer Contralateral Axillary Metastasis (CAM) to those with Locally Advanced Breast Cancer (LABC) and Metastatic Disease (M1) *Adjusted for age, race/ethnicity, hormone receptors. Citation Format: Meghan R. Flanagan, Stephanie Downs-Canner, Samantha Thomas, Astrid Botty van de bruele, Margaret Lillie, Kristalyn Gallagher, Tammeza Gibson, James Jakub, Alexandra Verosky, Sarah Tevis, Malia Brennan, Francys Verdial, Jennifer Q. Zhang, Leisha Elmore, Jennifer Plichta, Laura Rosenberger. A Multi-Institutional Review of Contralateral Axillary Metastases: Time for Reclassification as Local-Regional Event? [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 PO3-05-13.

Abstract PS05-09: A single-arm Phase II clinical study of fulvestrant combined with chemotherapy in the neoadjuvant treatment of HR+/HER2- locally advanced breast cancer

Abstract Background: HR+/HER2- breast cancer has been found to be less sensitive to neoadjuvant chemotherapy (NCT), leading to an objective response rate (ORR) of approximately 65%. Endocrine therapy combined with chemotherapy may help improve the ORR in these patients. The objective of this Phase II study was to evaluate the efficacy and safety of adding fulvestrant to NCT in patients with HR+/HER2- locally advanced breast cancer(LABC). Additionally, the study aimed to investigate the association of 18F-FES PET/CT and metabolites with efficacy. Methods: In this single-arm Phase II study, eligible patients were females with histologically confirmed HR+/HER2- LABC (Stage IIB-IIIC). Patients received fulvestrant (500 mg, on days 0, 14, 28, then every 28 days thereafter, every 4 weeks for six cycles) plus AC-T regimen, followed by surgery. Premenopausal women were administered a concomitant GnRH analogue. Patients underwent 18F-FES PET/CT before the initiation of fulvestrant, and plasma samples were collected for LC-MS analysis at baseline. The primary endpoint was ORR. Secondary endpoints included pathological complete response (tpCR) and safety. Results: From December 2020 to September 2022, 36 patients were enrolled. The median age was 53 years (range35-67). 78% were ECOG PS of 1, 69% were postmenopausal, 92% were nodal involved, and 83% were in stage III. After neoadjuvant therapy, the ORR was 86.1%. All patients completed the surgery, with a tpCR rate of 8.3% (3/36). 80.6% (29/36) patients were classified as Miller-Payne (MP) grade ≥3. Grade ≥3 treatment-emergent adverse events (TEAEs) occurred in 22% (8/36) of the participants. The most common TEAEs were neutropenia (13.9%) and leukopenia (8.3%). The expression of ER, PR, and Ki-67 in postoperative pathology significantly decreased compared to baseline (p &amp;lt; 0.05). Additionally, the change in ER expression was significantly correlated with the regression volume of primary breast tumors (R = 0.56, p = 0.0044). The decrease in ER value in patients with MP ≥ 4 was significantly larger than in patients with MP ≤ 3 (p = 0.0054). Among the 36 patients, 24 completed the 18F-FES PET/CT scan before initiating fulvestrant.The average SUVmax in primary breast lesions was 4.17 (range 1.00-12.80). The SUVmax of breast lesions was significantly correlated with clinical efficacy (p = 0.0018) and with changes in ER expression before and after treatment (R = 0.68, p = 0.00023). Meanwhile, the SUVmax of patients with MP ≥ 4 grade was significantly higher than that of patients with MP ≤ 3 grade (p=0.018). A total of 25 plasma samples were available for metabolic analysis. Among these samples, 13 differential metabolites were identified between patients with MP ≥ 4 grade and MP ≤ 3 grade, which were markedly enriched in 19 metabolic pathways. Conclusions: The addition of fulvestrant to NCT showed manageable toxicity and promising antitumor activity for patients with HR+/HER2- LABC. 18F-FES PET/CT might serve as a tool to predict the effectiveness of neoadjuvant combination therapy. Altered metabolites or metabolic pathways might be associated with the response to this combined treatment approach. Keywords: breast cancer, HR+/HER2-, fulvestrant, neoadjuvant treatment, 18F-FES PET/CT Citation Format: Qing Shao, Jing Wu, Ningning Zhang, Xiaohua Zeng. A single-arm Phase II clinical study of fulvestrant combined with chemotherapy in the neoadjuvant treatment of HR+/HER2- locally advanced 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 PS05-09.

Abstract PO4-12-03: PATIENT REPORTED OUTCOMES IN TERMS OF ARM AND SHOULDER FUNCTIONS AND QUALITY OF LIFE AND LYMPHEDEMA ARE AFFECTED BY THE STAGE, AND EXTENT OF AXILLARY SURGERY IN THE EARLY POSTOPERATIVE PERIOD OF PATIENTS WITH BREAST CANCER

Abstract This study evaluated whether lymphedema, patient-reported arm and shoulder morbidity and quality of life one year after axillary surgery are affected by stage or axillary surgery type between early stage patients and patients with locally advanced breast cancer who underwent surgery following neoadjuvant therapy. By determining the risk factors associated with severe lymphedema and deterioration of patient-reported outcomes, lymphedema could be prevented by early intervention to improve the prognosis of lymphedema and quality of life. Material and Methods: Between January 2021 and May 2022, a total of 253 breast cancer patients, 128 early stage and 125 locally advanced stage who underwent surgery including sentinel lymph node biopsy (SLNB) with/without axillary lymph node dissection (ALND) following neoadjuvant therapy were included in this study. The patients who underwent upfront surgery were defined as early-stage, and those who underwent surgery following neoadjuvant chemotherapy were considered as having locally advanced breast cancer (LABC) who have also participated in the prospective MF18-03 registry trial. Patients were prospectively evaluated by the SF-12 quality of life and QUICK-DASH hand, arm, and shoulder range of motion questionnaires and circumferential tape measurements of the arm width to evaluate the lymphedema before surgery, and 6 month- and 12-month assessments. The volume difference of 10% or more in the operated arm compared to the healthy arm was considered as lymphedema. Results: In the assessment of SF-12 quality of life questionnaire, there was a decrease in physical function scores at the 6th month despite recovery at the 12th month in both groups compared to the initial preoperative scores (p&amp;lt; 0,001). Moreover, patients with locally advanced breast cancer were found to have decreased SF-12 general health (p=0.024), vitality (p=0.034), and mental health scores in one year after surgery (p=0.004). Patients with mastectomy and locally advanced breast cancer were more likely to have a diminished arm and shoulder function as assessed with the QUICK-DASH questionnaire at the 6th and 12th months compared to those with breast conservation (6. month, p=0,009, 12. month, p=0.004), and early breast cancer, respectively (6. month, p=0.014, 12. month, p&amp;lt; 0.001) In the present cohort, lymphedema was detected in 19 (7.5%) patients including 16 cases with mild (11-20%), 2 cases with moderate (21-40%), and one case with severe (41-80%) lymphedema one year after surgery. Axillary dissection was found to be associated with an increased risk of lymphedema (SLNB, 5.0% vs ALND, 17.6%; p=0.005). Similarly, removal of &amp;gt;6 lymph nodes was also associated with an increased risk of lymphedema that was not statistically significant (&amp;lt;6 LNs, 6.4% vs &amp;gt;6LNs, 10.8%; p=0.277). Among those with LABC, however, patients with removal &amp;gt;6 LNs were more likely to have lymphedema (&amp;gt;6 LNs, 15.4% vs &amp;lt;6 LNs, 5.8%; p=0.096). Conclusion: These findings suggest that only an extensive axillary surgery was associated with an increased risk of breast cancer-related lymphedema. Patients with a mastectomy were more likely to have diminished arm and shoulder function compared to those with breast conservation. Furthermore, patients with locally advanced breast cancer were more likely to have a dispaired quality of life score and a limited arm and shoulder function regardless of the presence of lymphedema. Early prompt diagnosis and therapy of lymphedema can therefore potentially improve quality of life. Citation Format: Halime Gul Kilic, Selman Emiroglu, Ekin Ozgorgu, Mustafa Tukenmez, Atilla Bozdogan, Mahmut Muslumanoglu, Vahit Ozmen, Dilsad Sindel, Abdullah Igci, Aydan Oral, Neslihan Cabıoğlu. PATIENT REPORTED OUTCOMES IN TERMS OF ARM AND SHOULDER FUNCTIONS AND QUALITY OF LIFE AND LYMPHEDEMA ARE AFFECTED BY THE STAGE, AND EXTENT OF AXILLARY SURGERY IN THE EARLY POSTOPERATIVE PERIOD OF PATIENTS WITH 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 PO4-12-03.

Abstract PO5-26-04: The value of skin involvement in achieving of pCR in patients with locally advanced breast cancer

Abstract Objective: The management of patients with locally advanced breast cancer (LABC) with skin involvement (edema or thickening) continues to be one of the most controversial topics in mammology. The most recommended conventional treatment strategies include systemic therapy (chemotherapy/hormone therapy/biological agents) followed by local therapy (surgery and/or radiation therapy). However, approximately 1/3 of patients with locally advanced breast cancer are “resistant” to neoadjuvant chemotherapy (which is manifested by the persistence of skin involvement/edema/thickening). In this study, we aimed to identify the relationship between skin involvement and clinicopathological features of LABC patients. In particular, we sought to develop the algorithm for skin involvement measurement and examine the impact of skin involvement on the rate of pCR. Materials and methods: We performed a retrospective analysis of 182 patients diagnosed with LABC from 2010 to 2018 at N.N. Blokhin National Cancer Research Center. All patients were treated with neoadjuvant hormone- or chemotherapy and were considered as borderline for surgical resection because of partial skin edema. Ninety one women received surgery with consecutive radiotherapy (first group) and 50 women (second group) received radiotherapy (total dose 50 Gy) with consecutive surgery after systemic treatment. We developed the algorithm for skin involvement measurement, using a series of formulas. We further interrogated the impact of skin involvement on the rate of breast and lymph node pathological response in every group. Results: The median percentage of skin edema before systemic therapy was 76.3% in the first group and 70.1% in the second group. The median percentage of skin edema after systemic therapy was 62.3% in the first group and 69.1% in the second group. There wasn`t a statistically significant difference between the two groups (р=0,675 and р = 0,286, respectively). Breast pCR was seen in 19,7% (n=18) of the first group patients and partial response was seen in 72.6% (n=66). Breast pCR was seen in 30% (n=15) of the second group patients and partial response was seen in 70% (n=35). Results showed no significant differences between groups, р=0,342 and р = 0,12, respectively. Nodal pCR was reported in 23,9% (n=16) and partial response in 50,8% (n=34) of the 67 node-positive patients. Nodal pCR was reported in 31,6% (n=12) and partial response in 65,8% (n=29) of the 38 node-positive patients of the second group. There was no statistical difference in the groups, p &amp;gt;0,05. Conclusion: Increasing attention has been paid to LABC patients due to the clinical commonness and the complexity of treatment. Our study showed that LABC patients with incomplete clinical response to neoadjuvant systemic therapy can achieve pCR or partial response of tumor despite partial skin edema. In this study we developed the algorithm for skin involvement measurement. We hope that knowledge about volume of skin involvement revealed by this study might shed light on individualized therapies for these patients. In future, it allows to evaluate criteria of tumor resectability to improve patient selection. Therefore, prospective randomized trials are needed to improve optimization of the local treatment. Citation Format: Viktory Amosova, Alexander Petrovskiy, Oxana Trofimova, Mona Frolova, Alexey Rumyantsev. The value of skin involvement in achieving of pCR in patients with locally advanced 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 PO5-26-04.

Apriori prediction of chemotherapy response in locally advanced breast cancer patients using CT imaging and deep learning: transformer versus transfer learning.

Neoadjuvant chemotherapy (NAC) is a key element of treatment for locally advanced breast cancer (LABC). Predicting the response to NAC for patients with Locally Advanced Breast Cancer (LABC) before treatment initiation could be beneficial to optimize therapy, ensuring the administration of effective treatments. The objective of the work here was to develop a predictive model to predict tumor response to NAC for LABC using deep learning networks and computed tomography (CT). Several deep learning approaches were investigated including ViT transformer and VGG16, VGG19, ResNet-50, Res-Net-101, Res-Net-152, InceptionV3 and Xception transfer learning networks. These deep learning networks were applied on CT images to assess the response to NAC. Performance was evaluated based on balanced_accuracy, accuracy, sensitivity and specificity classification metrics. A ViT transformer was applied to utilize the attention mechanism in order to increase the weight of important part image which leads to better discrimination between classes. Amongst the 117 LABC patients studied, 82 (70%) had clinical-pathological response and 35 (30%) had no response to NAC. The ViT transformer obtained the best performance range (accuracy = 71 ± 3% to accuracy = 77 ± 4%, specificity = 86 ± 6% to specificity = 76 ± 3%, sensitivity = 56 ± 4% to sensitivity = 52 ± 4%, and balanced_accuracy=69 ± 3% to balanced_accuracy=69 ± 3%) depending on the split ratio of train-data and test-data. Xception network obtained the second best results (accuracy = 72 ± 4% to accuracy = 65 ± 4, specificity = 81 ± 6% to specificity = 73 ± 3%, sensitivity = 55 ± 4% to sensitivity = 52 ± 5%, and balanced_accuracy = 66 ± 5% to balanced_accuracy = 60 ± 4%). The worst results were obtained using VGG-16 transfer learning network. Deep learning networks in conjunction with CT imaging are able to predict the tumor response to NAC for patients with LABC prior to start. A ViT transformer could obtain the best performance, which demonstrated the importance of attention mechanism.

The Role of Circulating MicroRNAs in the Prediction of Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer in the Indian Population.

MicroRNAs (miRNAs) are known to play an important role in cancer cell proliferation, susceptibility of cancer cells to chemotherapy, and patient survival. Identifying miRNAs that can predict response to chemotherapy in locally advanced breast cancer (LABC), the most common variant, can help to choose appropriate drug regimensto suit the epigenetic profile of individual patients. To investigate the expression of the differentially expressed miRNAs identified by next-generation sequencing from a pilot study involving cases and controls, in peripheral blood mononuclear cells (PBMC) of patients with LABC during the course of neoadjuvant chemotherapy (NAC) and determine their role in response to chemotherapy. This study included 30 newly diagnosed LABC patients. Peripheral blood from every participant was collected before the start of chemotherapy, at the end of the third cycle, and at the end of the seventh cycle of NAC. Based on the results of a pilot study in a similar population with suitable controls, four differentially expressed miRNAs namely miR-24-2, miR-192-5p, miR-3609, and miR-664b-3p were considered to be validated in this study. The expression of these four miRNAs was examined by qRT-PCR, and their association with response to chemotherapy was analyzed. A significant change in the expression of miR-192-5p was found in responders (p = 0.001) over a period of seven cycles and the difference between the expression of miR-24-2 from baseline to the seventh cycle of NAC was higher in responders while compared to the non-responders (p < 0.05). miR-192-5p and miR-24-2 were identified as predictive biomarkers for response to NAC in south Indian patients with LABC.

Abstract PO4-22-09: Impact of time to surgery after neoadjuvant chemotherapy on pCR rate in locally-advanced breast cancer

Abstract Objective: Neoadjuvant chemotherapy along with surgical treatment are the important parts of treatment for locally advanced breast cancer. Extending the interval between the end of neoadjuvant chemotherapy and surgery may decrease tumor response in patients with locally advanced breast cancer. However, data if timing of surgery after neoadjuvant therapy affect the Pathologic complete response (pCR) rate is controversial. Materials and methods: We performed a retrospective analysis of 874 consecutive patients with IIIA-IIIC breast cancer that received neoadjuvant chemotherapy and surgery between 2000 and 2020 in N.N. Blokhin National Cancer Research Center. The median interval between the last injection of chemotherapy and surgery was 30 days (range 10 to 95 days). The variables were compared using log-rank statistics and Cox regression model. Results. Pathologic complete response (pCR) was registered in 250 (31,4%) patients. Univariate analysis showed that extending the interval between the end of neoadjuvant chemotherapy and surgery for each day were associated with decrease of probability of pCR (OR 0,982; p = 0,009). Patients with triple-negative and ER-/HER2+ achieved higher rates of pCR compared to luminal A subtype (p&amp;lt; 0,0001). Tumor grade, tumor size, Ki67 were independent predictive factors for tumor pCR (p &amp;lt; 0,001). Multivariate analysis also showed an independent negative effect of the time interval before surgery on the achieving pCR. Then the patients were stratified into three cohorts according to the time of surgery after neoadjuvant chemotherapy: &amp;lt; 22 days, 22-42 days, or &amp;gt;42 days. The odds ratio (OR) for pCR was 1 for &amp;lt; 22 days (reference), 0,833 for 22-42 days (p=0,332) and 0,576 for ≥43 days (p=0,033). Cox regression model demonstrated that the interval between the end of neoadjuvant chemotherapy and surgery (more than 42 days), tumor size, triple-negative and ER-/HER2+ were the significant predictive factors for pCR. Tumor grade, tumor size and age of patients were not independent predictive factors for in-breast pCR. Conclusion: Our study showed improved pCR if surgery was performed within 6 weeks after the end of neoadjuvant chemotherapy in locally advanced breast cancer. Results of multivariate logistic regression analysis to assess the probability of achieving complete pathomorphological regression Results of multivariate logistic regression analysis to assess the probability of achieving complete pathomorphological regression Citation Format: Alexander Petrovskiy, Viktory Amosova, Oxana Trofimova, Mona Frolova, Anastasya Soloshenko, Alexey Rumyantsev. Impact of time to surgery after neoadjuvant chemotherapy on pCR rate in locally-advanced 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 PO4-22-09.