Neoadjuvant Chemotherapy Group Research Articles

Abstract PO2-22-10: Surgical outcomes after neoadjuvant chemotherapy with and without immunotherapy in patients with triple negative breast cancer

Abstract Background: The KEYNOTE-522 trial demonstrated that the addition of neoadjuvant pembrolizumab to neoadjuvant chemotherapy (NAC) for the treatment of early-stage triple negative breast cancer (TNBC) significantly improves rates of both pathologic complete response (pCR) and event-free survival. The impact of adding immunotherapy to NAC on surgical outcomes, however, is unknown. The purpose of this study is to compare 90-day surgical complication rates and timing to subsequent adjuvant therapy of patients undergoing neoadjuvant chemotherapy for stage I-III TNBC with and without immunotherapy. Methods: Patients treated at University of California, Los Angeles with neoadjuvant therapy for TNBC between 2018-2022 were identified retrospectively. Patient comorbidities, tumor characteristics, type of surgery, 90-day postoperative minor and major complications, timing to adjuvant therapy, and oncologic outcomes were reviewed and analyzed. Major complications were defined as those requiring reoperation or hospitalization. Results: A total of 44 patients were included, 15 patients received neoadjuvant chemotherapy with immunotherapy (NAC-I) and 29 patients received neoadjuvant chemotherapy alone (NAC). There was no difference in patient comorbidities between the groups. Compared to the NAC group, significantly more patients in the NAC-I group had stage II or III tumors (58.6% vs. 86.7%, respectively, p=0.028). 73% of patients in the NAC-I group underwent mastectomy compared to only 44% of patients in the NAC group (p=0.111). In total, 23 patients underwent reconstruction with mastectomy, 6 patients underwent immediate DIEP flap (4 in NAC-I group and 2 in NAC group) and 17 underwent immediate tissue expander (7 in NAC-I and 10 in NAC group). 80% of patients in the NAC-I experienced a pCR compared to only 44% in the NAC group (p=0.026). A total of 15 patients (34.1%) experienced surgical complications and there was no significant difference in the complication rate between the groups (p= 0.552). Five patients (33%) in the NAC-I group experienced minor complications of seroma requiring aspiration (n=4), cellulitis requiring antibiotics (n=1), or wound dehiscence requiring local wound care (n=2). No patients in the NAC-I group had major complications. Ten patients (33%) in the NAC group experienced complications, including 6 minor complications and 4 major complications including postoperative bleeding or flap necrosis requiring unplanned return to surgery or hyperbaric oxygen treatment. On multivariable regression analysis, controlling for patient characteristics, tumor stage, and preoperative immunotherapy, only younger age was a statistically significant variable associated with increased risk of surgical complications (p=0.012). Median time to adjuvant therapy, including radiation and/or systemic therapy, was similar between NAC-I and NAC groups, at 32 and 36 days, respectively (p=0.37). In the NAC-I group, 14 patients (93.3%) had adjuvant systemic therapy including pembrolizumab alone (n=12), pembrolizumab with olaparib (n=1) or capecitabine alone (n=1). In the NAC group, 11 patients (37.9%) underwent adjuvant systemic treatment including chemotherapy with either capecitabine (n=1), pembrolizumab (n=1), or olaparib (n=2); or single agent capecitabine (n=6) or olaparib (n=1). Conclusions: Despite patients in the NAC-I group having more advanced stage tumors and undergoing more extensive surgery and reconstruction compared to those in the NAC alone group, a significantly higher rate of surgical complications was not observed in the NAC-I group and there was no significant difference in time to adjuvant therapy between the two groups. Similar to results from the KEYNOTE-522 trial, more patients in the NAC-I group experienced a pCR compared to NAC alone. Larger studies are needed to continue to assess and optimize the surgical safety of neoadjuvant immunotherapy with chemotherapy in patients with TNBC. Citation Format: Anouchka Coste Holt, Maurice Berkowitz, Nicholas McAndrew, Courtney Smith, Jennifer Baker, Nimmi Kapoor. Surgical outcomes after neoadjuvant chemotherapy with and without immunotherapy in patients with triple 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 PO2-22-10.

Abstract PO4-17-03: Neoadjuvant chemotherapy in invasive lobular carcinoma of the breast: A retrospective study on survival outcomes

Abstract Background: Neoadjuvant chemotherapy (NAC) is a well-established component of breast cancer management. Invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) are often treated similarly, but many studies are demonstrating a major difference in treatment responses according to the histopathological type of cancer. Aim: To evaluate the overall survival of patients with ILC after NAC compared with adjuvant chemotherapy. Methods: This retrospective cohort study included patients treated for breast ILC between 1998 and 2016 at the Center for Breast Diseases of de CHU de Québec – Université Laval, a tertiary breast cancer center. The primary outcomes were the overall survival (OS) and the recurrence-free survival (RFS) of ILC patients receiving NAC compared with patients who received only adjuvant chemotherapy. The follow-up was censored at the last hospital contact. The secondary outcomes were the locoregional recurrence, pathological complete response (pCR), and pCR impact on survival. Results: During the study period, 265 women were treated for ILC, of which 72 had NAC, and 193 had adjuvant therapy. No significant differences were observed regarding the patient’s characteristics (age, BMI, smoking, menopausal status, and use of hormonal replacement therapy). A T4 disease was found in 29.2% of the NAC group (vs. 0 in the adjuvant group), but the N2-3 rate was lower in the NAC group (5.6% vs. 22.3%, P=0.011). More patients in the NAC group underwent mastectomy (65.3% vs. 29.5%, P< 0.0001) and axillary dissection (80.6% vs. 50.8%, P< 0.0001). Three (4.2%) patients in the NAC group achieved a pCR. The rates of radiotherapy (P=0.851) and hormonal therapy (P=0.694) were similar between the two groups. The mean follow-up was 8 years. After adjustment for age, T, N, surgery type, radiotherapy, and hormonal therapy, the NAC group showed significantly lower 10-year OS (56.2% vs. 80.7%, P< 0.0001) and RFS (51.8% vs. 72.7%, P=0.0004) compared with the adjuvant group. There were no differences in the 10-year local recurrence rate (90.6% vs. 93.5%, P=0.11). In a Cox regression analysis of RFS considering the previously mentioned covariables, more events in the NAC group (OR=2.52, 95%CI: 1.39-4.58, P=0.002) and patients with N2-N3 (OR=3.68, 95%IC: 2.00-6.80, P< 0.01). Conclusion: Despite the general belief that ILC and IDC should be treated similarly, this study strongly suggests that ILC seems to have a poorer response to NAC. Patients diagnosed with ILC might benefit from a more aggressive surgical approach followed by adjuvant chemotherapy, no matter the severity of the disease. Additional long-term prospective comparative studies are needed to support this statement and improve the management of these patients. Citation Format: Virginie Gauthier, Anne-Julie Simard, Christine Desbiens, Brigitte Poirier, Julie Lemieux, Dominique Boudreau, Dominique Leblanc, Claudya Morin, Jean-Charles Hogue, Éric Poirier. Neoadjuvant chemotherapy in invasive lobular carcinoma of the breast: A retrospective study on survival outcomes [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 PO4-17-03.

Efficacy of total neoadjuvant chemotherapy in the FLOT regimen in patients with locally advanced gastric and gastroesophageal junction: results of a phase II study

Background. The established approach notably improving the therapeutic outcomes for locally advanced gastric cancer and gastroesophageal junction cancer, presently entails the amalgamation of perioperative chemotherapy aligned with the FLOT protocol and surgical intervention. However, this approach harbors limitations, as only half of the patient cohort successfully completes the entire prescribed course of drug therapy. The potential solution to this problem lies in the complete transfer of the chemotherapy volume to the preoperative period and the execution of total neoadjuvant chemotherapy with FLOT regimen.Aim. Aim is to conduct a comparative assessment of the efficacy and safety between total neoadjuvant and perioperative chemotherapy with FLOT regimen for patients with locally advanced gastric cancer and gastroesophageal junction cancer.Materials and methods. In a retrospective study we enrolled patients with histologically confirmed locally advanced gastric cancer and gastroesophageal junction cancer meeting clinical stage criteria T2–4 and N0–3, without of distant metastases, treated between 2014 and 2020 at Federal State Budgetary Institution “N. N. Blokhin National Medical Research Center of Oncology” оf the Ministry of Health of the Russian Federation and Moscow City Oncologic Hospital No. 62 Department of Healthcare of Moscow. Participants in the control group underwent 8 courses of perioperative chemotherapy (4 preoperatively and 4 postoperatively), while those in the experimental group received 8 courses of total neoadjuvant chemotherapy. Both groups received drug therapy according to the FLOT protocol: 5-fluorouracil 2600 mg/m2 , intravenous drip, over 24 hours, leucovorin 200 mg/m2 , intravenous drip, oxaliplatin 85 mg/m2 , intravenous drip, docetaxel 50 mg/m2 , intravenous drip, on day 1, with a 14-day intercourse interval. The primary endpoint was one-year progression-free survival.Results. In the study included 187 patients. Participants were divided into two groups: 95 in the total neoadjuvant chemotherapy group and 92 in the perioperative chemotherapy group. The one-year progression-free survival was higher in the total neoadjuvant chemotherapy group at 79 %, compared to 68 % in the perioperative chemotherapy group (HR 0.54, 95 % confidence interval 0.32–0.9, p = 0.02). Median disease-free survival was 27.2 and 19.5 months in the neoadjuvant and perioperative chemotherapy groups, respectively. The tolerability of the entire planned drug treatment regimen was superior in the total neoadjuvant chemotherapy group, reaching 88.4 %, as opposed to 57.6 % in the perioperative chemotherapy group (p = 0.0001).Conclusion. Among patients with locally advanced gastric cancer and gastroesophageal junction cancer, the application of total neoadjuvant chemotherapy according to the FLOT protocol, administered over 8 courses, demonstrated enhanced one-year progression-free survival and improved tolerability of the entire planned treatment regimen.

Abstract PO1-28-09: Rethinking the value of pathologic complete response rate for the survival outcomes of early triple-negative breast cancer treated with neoadjuvant chemotherapy: a systematic review and network meta-analysis

Abstract Background: Neoadjuvant chemotherapy (NACT) has been more frequently used in breast cancer, but it’s controversial whether NACT or adjuvant chemotherapy (ACT) is more effective in improving survival outcomes for triple-negative breast cancer (TNBC) patients. Recent studies also proposed pathologic complete response (pCR) could not be a robust surrogate for survival outcomes in certain types of breast cancer. To address these questions, a general meta-analysis and a network meta-analysis (NMA) were conducted to compare the survival outcomes of patients with pCR, non-pCR after NACT and ACT. The cut-off pCR rate was also declared to indicate when NACT produces equivalent survival outcomes to ACT (Registration: PROSPERO CRD42022336732). Methods: Databases including PubMed, Embase, Web of science and Cochrane library were searched up to June 2023 to investigate studies comparing NACT and ACT, as well as randomized controlled trials (RCTs) comparing different regimens in NACT or ACT settings in early operable TNBC patients. Heterogeneity was assessed using χ² based Q-test and I², combined with hazard ratios (HRs) with 95% confidence intervals (CI) computed for overall survival (OS), and disease-free survival (DFS, or event-free survival). The NMA with a Bayesian framework was conducted using both random and fixed effect model. The Weighted Least Square method and the Least Absolutely Deviation method were used to determine the cut-off pCR rates of OS and DFS. Results: A total of 35 studies involving 21 RCTs and 34143 TNBC patients were included. The general meta-analysis comprised 14 cohort studies. Eight high-quality cohort studies with propensity score matching and 21 RCTs were included in NMA. The pooled pCR rate for NACT was 42.2% (95% CI 37.8%-46.8%). Overall, the NACT cohort showed significantly worse OS and DFS than ACT cohort (HR=1.67, 95% CI 1.22-2.31; HR=1.37, 95% CI 1.14-1.64). However, patients with pCR after NACT showed improved OS than ACT (HR=0.58, 95% CI 0.50-0.66), while the patients without pCR after NACT had pooper OS than ACT (HR=2.03, 95% CI 1.88-2.19). As for DFS, there was no statistically difference between pCR after NACT and ACT groups (HR=1.04, 95% CI 0.63-1.73), while patients without pCR after NACT had significantly worse DFS than ACT (HR=2.65, 95% CI 1.98-3.55). From the NMA, the OS and DFS were better when combining modern target therapy such as Bevacizumab, PARPi, and PD-1/PD-L1 inhibitor (Figure 1), but not achieving pCR completely negated the benefits of newer drugs. Adding adjuvant capecitabine to patients not achieving pCR seemed to favor the OS. It was predicted that when the pCR rates were 64.7% and 46.9% (Figure 2), respectively, the OS and DFS of patients treated with NACT would be the same as those of patients treated with ACT. Conclusions: Higher pCR rate after NACT was associated with improved OS compared with ACT in TNBC patients. However, failure to achieve pCR after NACT resulted in worse survival outcomes than ACT. NACT had similar survival outcomes with ACT only when the pCR rate was at least 46.9%. The development of effective NACT regimens is beneficial for breast cancer patients. Figure 1. Forest plot of the Hazard Ratio for OS and DFS in TNBC patients pCR: pathological complete response; Bev: Bevacizumab; Pt: platinum; NACT: neoadjuvant chemotherapy; ACT: adjuvant chemotherapy; vel: veliparib; PDi:PD1/PDL1 inhibitor; X: capecitabine Figure 2. The cut-off value of pCR when NACT and ACT have the same Hazard Ratio based on OS and DFS. pCR: pathological complete response; Bev: Bevacizumab; Pt: platinum; NACT: neoadjuvant chemotherapy; ACT: adjuvant chemotherapy Citation Format: Xiaoying Qiao, Shu Wang, Taobo Hu, Baosheng Liang. Rethinking the value of pathologic complete response rate for the survival outcomes of early triple-negative breast cancer treated with neoadjuvant chemotherapy: a systematic review and network meta-analysis [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 PO1-28-09.

Abstract PO5-03-05: Rethinking the value of pathologic complete response rate for the survival outcomes of early triple-negative breast cancer treated with neoadjuvant chemotherapy: a systematic review and network meta-analysis

Abstract Background: Neoadjuvant chemotherapy (NACT) has been more frequently used in breast cancer, but it’s controversial whether NACT or adjuvant chemotherapy (ACT) is more effective in improving survival outcomes for triple-negative breast cancer (TNBC) patients. Recent studies also proposed pathologic complete response (pCR) could not be a robust surrogate for survival outcomes in certain types of breast cancer. To address these questions, a general meta-analysis and a network meta-analysis (NMA) were conducted to compare the survival outcomes of patients with pCR, non-pCR after NACT and ACT. The cut-off pCR rate was also declared to indicate when NACT produces equivalent survival outcomes to ACT (Registration: PROSPERO CRD42022336732). Methods: Databases including PubMed, Embase, Web of science and Cochrane library were searched up to June 2023 to investigate studies comparing NACT and ACT, as well as randomized controlled trials (RCTs) comparing different regimens in NACT or ACT settingsin early operable TNBC patients. Heterogeneity was assessed using χ² based Q-test and I², combined with hazard ratios (HRs) with 95% confidence intervals (CI) computed for overall survival (OS), and disease-free survival (DFS, or event-free survival). The NMA with a Bayesian framework was conducted using both random and fixed effect model. The Weighted Least Square method and the Least Absolutely Deviation method were used to determine the cut-off pCR rates of OS and DFS. Results: A total of 35 studies involving 21 RCTs and 34143 TNBC patients were included. The general meta-analysis comprised 14 cohort studies. Eight high-quality cohort studies with propensity score matching and 21 RCTs were included in NMA. The pooled pCR rate for NACT was 42.2% (95% CI 37.8%-46.8%). Overall, the NACT cohort showed significantly worse OS and DFS than ACT cohort (HR=1.67, 95% CI 1.22-2.31; HR=1.37, 95% CI 1.14-1.64). However, patients with pCR after NACT showed improved OS than ACT (HR=0.58, 95% CI 0.50-0.66), while the patients without pCR after NACT had pooper OS than ACT (HR=2.03, 95% CI 1.88-2.19). As for DFS, there was no statistically difference between pCR after NACT and ACT groups (HR=1.04, 95% CI 0.63-1.73), while patients without pCR after NACT had significantly worse DFS than ACT (HR=2.65, 95% CI 1.98-3.55). From the NMA, the OS and DFS were better when combining modern target therapy such as Bevacizumab, PARPi, and PD-1/PD-L1 inhibitor, but not achieving pCR completely negated the benefits of newer drugs. Adding adjuvant capecitabine to patients not achieving pCR seemed to favor the OS. It was predicted that when the pCR rates were 64.7% and 44.6%, respectively, the OS and DFS of patients treated with NACT would be the same as those of patients treated with ACT. Conclusions: Higher pCR rate after NACT was associated with improved OS compared with ACT in TNBC patients. However, failure to achieve pCR after NACT resulted in worse survival outcomes than ACT. NACT had similar survival outcomes with ACT only when the pCR rate was at least 44.6%. The development of effective NACT regimens is beneficial for breast cancer patients. Citation Format: Xiaoying Qiao, Taobo Hu, Baosheng Liang, Shu Wang. Rethinking the value of pathologic complete response rate for the survival outcomes of early triple-negative breast cancer treated with neoadjuvant chemotherapy: a systematic review and network meta-analysis [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 PO5-03-05.

Abstract PO1-06-04: Immune checkpoint inhibitors for triple-negative inflammatory breast cancer (INCORPORATE): an international multicenter retrospective analysis

Abstract Background: Inflammatory breast cancer (IBC) is an aggressive clinical presentation of breast cancer (BC). Immune checkpoint inhibitors (ICIs) combined with chemotherapy provided an overall survival (OS) benefit in the metastatic setting and an even-free survival (EFS) benefit in patients (pts) with early triple-negative (TN) BC, respectively. Patients with TN-IBC were under-represented or excluded in pivotal trials and commonly not evaluated in subgroup analyses. Methods: We conducted a retrospective, multicenter, international, observational study to evaluate the clinical benefit of ICIs in pts with TN-IBC (defined as cT4d per AJCC TNM, 8th ed., ER < 1% and PgR < 1%, HER2: negative). Pts with early-stage TN-IBC were included if they received an ICI combined with neoadjuvant chemotherapy (NACT) (Group 1). Pts with metastatic TN-IBC were included if they received ICI monotherapy or in association with first-line chemotherapy (Group 2). Treatment was administered according to guideline recommendations (in PD-L1+ metastatic IBC and regardless of PD-L1 in early IBC), in clinical trials, or off-label (regardless of PD-L1 expression status in metastatic IBC). Endpoints were pathological complete response (pCR) and 1-year EFS rate for group 1 (calculated from date of first cycle of NACT to any recurrence or death), and progression-free survival (PFS) for group 2. Correlative analyses were provided (significance at p-value < 0.05). Results: We included 59 pts from 8 international referral centers. 15 pts had early IBC (Group 1), and 44 pts had metastatic disease (Group 2). Patient characteristics and outcomes are shown in Table 1. Among the 15 pts from Group 1, 10 received anthracycline, taxane and carboplatin-based (AC-CbT) NACT with pembrolizumab, 3 neoadjuvant paclitaxel-carboplatin chemotherapy with pembrolizumab, 2 neoadjuvant nab-paclitaxel with atezolizumab. One pt progressed on NACT, 2 pts are still receiving NACT. Among 13 pts evaluable for response, 6/13 (46%) achieved a pCR. After a median follow-up of 7.1 months, the median EFS was 12.9 months and the 1-year EFS rate was 70%. The median OS was 15.7 months. Among pts from Group 2, PD-L1 status was positive (IC 1% or CPS 10) in 27/44 pts (61%), negative in 5/44 pts (11%) and unknown in 6/44 pts (13%). At a median follow-up of 24.3 months, median PFS and OS were 4.1 and 15.7 months. As backbone chemotherapy in first line setting, 6 pts received AC-CbT regardless of PD-L1 status (mPFS: 8.6 months), 21 taxane-based/anthracycline-free chemotherapy (mPFS: 5.3 months), 14 other chemotherapy regimens (mPFS: 2.1 months) and 3 single-agent immunotherapy (mPFS: 50.1 months). Three of 6 patients who received AC-CbT underwent surgery and radiotherapy. In Group 2, after adjusting for the number of metastatic sites (>1 vs. 0-1), PD-L1 status (positive vs. negative vs. unknown) and de novo metastatic disease (yes vs. no), AC-CbT chemotherapy (HR 0.05; 95% CI: 0.01-0.56; p=.015) and taxane-based chemotherapy (HR 0.20; 95% CI: 0.06-0.68; p=.009) were both associated with longer PFS. Conclusions: This multicenter retrospective analysis of TN-IBC treated with combination of chemotherapy and IOs showed relatively low pathology response, EFS and clinical benefit suggesting need to further investigate the role of immunotherapy in this aggressive disease. Table 1. Patient characteristics and outcomes Citation Format: Carmine Valenza, Dario Trapani, Paola Zagami, Gabriele Antonarelli, Luca Boscolo Bielo, Eleonora Nicolò, Joana Mourato Ribeiro, Lorenzo Guidi, Carolina REDUZZI, Martina Spotti, Elisabetta Munzone, Javier Cortés, Barbara Pistilli, Sara Tolaney, Naoto Ueno, Rachel Layman, Massimo Cristofanilli, Lisa Carey, Filipa Lynce, Wendy Woodward, Giuseppe Curigliano. Immune checkpoint inhibitors for triple-negative inflammatory breast cancer (INCORPORATE): an international multicenter retrospective analysis [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 PO1-06-04.

Abstract PO3-25-05: Eribulin Induces Chromosomal Instability and Enhances cGAS Expression in the Nucleus of Triple-Negative Breast Cancer

Abstract Background: Eribuliln (ERI), a microtubule polymelization, is approved for locally advanced or metastatic breast cancer. However, its effects on drug-naive cancers are not well understood. In EMBRACE trial, ERI improves overall survival (OS) of the patients with metastatic breast cancer. This result might suggest that ERI could be involved in the immune system. In particular, there are a few reports on the effects of ERI on the innate immune system. This study aimed to investigate how ERI influences the innate immune system, focusing on the cyclic-GMP-AMP synthase (cGAS), a DNA sensor that triggers the production of type-I interferons. Methods: Clinical samples from the JONIE-3 trial were analyzed using immunohistochemistry (IHC). 121 patients were assigned to 2 different neoadjuvant chemotherapy (NAC) groups receive ERI (Group E) or paclitaxel (Group P) followed by FEC. The patients of both groups were performed biopsy before and after chemotherapy. We performed IHC on 56 samples and examined for association with pathological complete response (pCR), which was defined as no invasive redidual tumor tissue in the breast. Additionally, 5 different cell lines were established to evaluate the acute and chronic effects of ERI treatment. The cell lines were as follows: no treatment (control), PTX for short time (PTX short), PTX for long time (PTX long), ERI for short time (ERI short) and ERI for long time (ERI long). We evaluated the acute effects of short-term dosing, while the chronic effects of long-term dosing, which mimic resistance to treatment. Protein expression of the cGAS-STING pathway was examined, along with cGAS and IFNβ expression levels and their impact on cell division in the above cell lines. Then at the cellular level, each cell lines were evaluated for differences in cGAS and IFNβ expression and their effects on cell division. The differences in cGAS expression between cytoplasmic and nuclear fractions were verified by the cell fractuation assay. In addition, mitotic abnormalities and cell proliferation were also assessed. Results: In the clinical trial, ERI did not significantly differ from paclitaxel in terms of pathological complete response (pCR). However, high cGAS expression in Group E (ERI) correlated with increased pCR rates, while no such correlation was observed in Group P (PTX) (Figure). Additionally, High IFNβ expression in Group E also correlated with increased pCR rates, differed from Group P. In vitro, ERI upregulated cGAS, STING, pIRF3, and IFNβ protein expression compared to PTX. Notably, ERI induced elevated cGAS expression in the nucleus, as confirmed by immunofluorescence and cell fracturation assays. Additionally, PTX and ERI differed in their ability to cause mitotic abnormalities. PTX induced more micronuclei cells than ERI, on the other hand ERI induced more micronuclei cells and mitotic slippage. These results were also verified by live cell imaging. Finally, the knockdown of cGAS resulted in accelerated cell proliferation. Conclusion: ERI promoted chromosomal instability, leading to increased cGAS expression, particularly in the nucleus. These findings contribute to our understanding of ERI's effects on the innate immune response in triple-negative breast cancer, potentially paving the way for improved therapeutic strategies. The differences in intensity scores between GroupP and GroupE in the immunostaining of cGAS High cGAS expression in Group E correlated with increased pCR rates (p=0.0375), while no such correlation was observed in Group P (p=0.2983). Citation Format: Hideyuki Yamada, Mamoru Takada, Aussie Suzuki, Yu Muhan, Takeshi Nagashima, Hiroshi Fujimoto, Junta Sakakibara, Masaharu Kasuya, Takahiko Kawate, Daishu Miura, Masato Suzuki, Masaru Miyashita, Kazutaka Narui, Yoshie Hasegawa, Takashi Ishikawa, Masayuki Otsuka. Eribulin Induces Chromosomal Instability and Enhances cGAS Expression in the Nucleus of Triple-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 PO3-25-05.

Pathologic and survival outcomes following radical cystectomy for “progressive” and “de novo” muscle-invasive bladder cancer: A meta-analysis stratified by neoadjuvant chemotherapy status

ObjectiveTo compare survival and pathologic outcomes in patients with progressive muscle-invasive bladder cancer (pgMIBC) and de novo muscle-invasive bladder cancer (dnMIBC) after radical cystectomy (RC), with a focus on the role of neoadjuvant chemotherapy (NAC). MethodsA comprehensive literature search was conducted on PubMed and EMBASE databases to identify studies comparing pgMIBC to dnMIBC. Survival outcomes, including cancer-specific survival (CSS), overall survival (OS), and recurrence-free survival (RFS), and pathologic outcomes (rates of ≤pT1, pT0, pT3/T4, and pN+ disease) were compared between pgMIBC and dnMIBC. ResultsThe analysis included 19 cohorts from 16 studies, categorized into 3 groups based on NAC use: 1. patients who underwent RC and were all treated with NAC (RC + NAC only group); 2. patients who underwent RC, with or without NAC (RC +/- NAC group); 3. patients who only underwent RC without NAC (RC only group). Compared to dnMIBC, pgMIBC demonstrated worse outcomes for CSS, OS, and RFS. In the RC + NAC only group (3 cohorts), the hazard ratio (HR) for CSS was 1.52 (95% confidence interval [CI] = 1.05–2.2), while the HR for OS was 1.46 (95%CI = 1.05–2.02). Similarly, in the RC +/- NAC group (6 cohorts for CSS and 3 cohorts for OS), the HR for CSS was 1.27 (95%CI = 1.05–1.55), and the HR for OS was 1.27 (95%CI = 1.08–1.51). There were no significant differences observed in pathologic outcomes, including rates of ≤pT1, pT0, and pT3/T4 disease, across all subgroups. However, pgMIBC was associated with a higher risk of nodal metastatic (pN+) disease in the RC + NAC only group (4 cohorts, relative risk [RR] = 1.43, 95%CI = 1.12–1.84). ConclusionsThe findings highlight the potentially worse prognosis in patients with pgMIBC compared to dnMIBC, even with the modern use of NAC. The study emphasizes the importance of careful patient counseling, further classification of patients for treatment selection, and the consideration of additional or innovative systemic therapies for pgMIBC.

Association of Neoadjuvant Chemotherapy With Postoperative Outcomes in Immediate Prepectoral Prosthetic Breast Reconstruction.

Neoadjuvant chemotherapy (NACT) followed by total mastectomy and immediate reconstruction has become an important strategy in the treatment of breast cancer. Although the safety of subpectoral implant-based breast reconstruction with NACT has been extensively evaluated, the safety in prepectoral reconstruction has not been clearly elucidated. We aimed to evaluate the association of NACT with immediate prepectoral breast reconstruction outcomes. A retrospective review of patients who underwent total mastectomy and immediate implant-based prepectoral breast reconstruction between May and December 2021 was conducted. Patients were categorized into 2 groups: those receiving NACT and those not receiving it. Postoperative complication rates were compared between the 2 groups. The independent association between NACT and the complication profiles was evaluated. Propensity score matching was also conducted. We analyzed 343 cases, including 85 who received NACT treatment and 258 who did not. Compared with the non-NACT group, the NACT group was younger, had a higher body mass index, and a higher rate of adjuvant radiotherapy. There were no differences in the rates of overall complications or type of complication between the 2 groups. In the multivariable logistic analyses, NACT did not show a significant association with the development of adverse outcomes. Similar results were observed in propensity score matching analyses. Our results suggest that receiving NACT may not have a significant detrimental effect on the postoperative outcomes of immediate prepectoral prosthetic reconstructions. Conducting prepectoral implant-based reconstruction in the setting of NACT might be safe and provide acceptable outcomes.

Clinicopathologic and molecular correlates to neoadjuvant chemotherapy-induced pathologic response in breast angiosarcoma.

Both primary and secondary breast angiosarcoma (AS) are characterized by multifocal presentation and aggressive behavior. Despite multimodality therapy, local and distant relapse rates remain high. Therefore, neoadjuvant chemotherapy (NACT) is employed to improve the R0 resection rates and survival, but its benefits remain controversial. Herein, we investigate pathologic and molecular correlates to NACT-induced histologic response in a group of 29 breast AS, 4 primary and 25 radiation-associated (RA). The two NACT regimens applied were anthracycline- and non-anthracycline-based. The pathologic response grade was defined as: I: ≤ 50%, II: 51%-90%, III: 91%-99%, and IV: 100%. An additional 45 primary AS and 102 RA-AS treated by surgery alone were included for survival comparison. The genomic landscape was analyzed in a subset of cases and compared to a cohort of AS without NACT on a paired tumor-normal targeted DNA NGS platform. All patients were females, with a median age of 31 years in primary AS and 68 years in RA-AS. All surgical margins were negative in NACT group. The NACT response was evenly divided between poor (Grades I-II; n = 15) and good responders (Grades III-IV; n = 14). Mitotic count >10/mm2 was the only factor inversely associated with pathologic response. By targeted NGS, all 10 post-NACT RA-AS demonstrated MYC amplification, while both primary AS harbored KDR mutations. TMB or other genomic alterations did not correlate with pathologic response. All four patients with Grade IV response remained free of disease. The good responders had a significantly better disease-specific survival (p = 0.04). There was no survival difference with NACT status or the NACT regimens applied. However, NACT patients with MYC-amplified tumors showed better disease-free survival (p = 0.04) compared to MYC-amplified patients without NACT. The overall survival of NACT group correlated with size >10 cm (p = 0.02), pathologic response (p = 0.04), and multifocality (p = 0.01) by univariate, while only size >10 cm (p = 0.03) remained significant by multivariate analysis.

Potential utility of pretreatment serum miRNAs for optimal treatment selection in advanced high-grade serous ovarian cancer.

The primary treatment of patients with advanced ovarian cancer is selected from whether primary debulking surgery or neoadjuvant chemotherapy. We investigated whether pretreatment serum microRNA profiles are useful for selecting patients with advanced high-grade serous ovarian cancer who obtain better outcomes from undergoing primary debulking surgery or neoadjuvant chemotherapy. Consecutive patients with clinical stage IIIB-IVB and serum microRNA data were selected. Patients who underwent primary debulking surgery or neoadjuvant chemotherapy were subjected to 1:1 propensity score matching before comparing their progression-free survival using Cox modelling. Progression-free probabilities for the selected microRNA profiles were calculated, and the estimated progression-free survival with the recommended primary treatment was determined and compared with the actual progression-free survival of the patients. Of the 108 patients with stage IIIB-IVB disease, the data of 24 who underwent primary debulking surgery or neoadjuvant chemotherapy were compared. Eleven and three microRNAs were independent predictors of progression-free survival in patients who underwent primary debulking surgery and neoadjuvant chemotherapy, respectively. Two microRNAs correlated significantly with complete resection of the tumours in primary debulking surgery. No differences were found between the actual and estimated progression-free survival in the primary debulking surgery and neoadjuvant chemotherapy groups (P>0.05). The recommended and actual primary treatments were identical in 27 (56.3%) of the 48 patients. The median improved survival times between recommended and actual treatment were 11.7 and 32.6months for patients with actual primary debulking surgery and neoadjuvant chemotherapy, respectively. Pretreatment microRNA profiles could be used to select subgroups of patients who benefited more from primary debulking surgery or neoadjuvant chemotherapy and might contribute to selecting the optimal primary treatment modality in advanced high-grade serous ovarian cancer patients.

Comparing survival outcomes between neoadjuvant and adjuvant chemotherapy within T2N1M0 stage hormone receptor-positive, HER2-negative breast cancer: a retrospective cohort study based on SEER database.

Guideline recommendations for the application of neoadjuvant chemotherapy (NACT) in T2N1M0 stage hormone receptor-positive, HER2-negative (HR + /HER2-) breast cancer are ambiguous. The debate continues regarding whether NACT or adjuvant chemotherapy (ACT) offers superior survival outcomes for these patients. Female patients diagnosed with HR + /HER2- breast cancer at T2N1M0 stage between 2010 and 2020, were identified from the Surveillance, Epidemiology, and End Results database and divided into two groups, the NACT group and the ACT group. Propensity score matching (PSM) was utilized to establish balanced cohorts between groups, considering baseline features. Kaplan-Meier (K-M) analysis and the Cox proportional hazards model were executed to assess the efficacy of both NACT and ACT in terms of overall survival (OS) and breast cancer-specific survival (BCSS). A logistic regression model was employed to examine the association between predictive variables and response to NACT. After PSM, 4,682 patients were finally included. K-M curves showed that patients receiving NACT exhibited significantly worse OS and BCSS when compared with patients undergoing ACT. Multivariable Cox analysis indicated that not achieving pathologic complete response (non-pCR) after NACT (versus ACT), was identified as an adverse prognostic factor for OS (HR 1.58, 95% CI 1.36-1.83) and BCSS (HR 1.70, 95% CI 1.44-2. 02). The logistic regression model revealed that low tumor grade independently predicted non-pCR. Among T2N1M0 stage HR + /HER2- patients, OS and BCSS of NACT were inferior to ACT. Patients who attained non-pCR after NACT demonstrated significantly worse survival outcomes compared with those who received ACT.

Neoadjuvant chemotherapy does not improve survival for patients with high volume colorectal peritoneal metastases undergoing cytoreductive surgery.

Colorectal peritoneal metastases (CRPM) affects 15% of patients at initial colorectal cancer diagnosis. Neoadjuvant chemotherapy (NAC) prior to cytoreductive surgery (CRS) has been demonstrated to be a safe and feasible option, however there is limited data describing its efficacy in advanced peritoneal disease. This study evaluated the effect of NAC on survival in patients with high volume CRPM undergoing CRS with or without HIPEC. A retrospective review of all patients who underwent CRS with or without HIPEC for CRPM from 2004 to 2019 at our institution was performed. The cohort was divided based on peritoneal carcinomatosis index (PCI) at surgery: Low Volume (PCI ≤ 16) and High Volume (PCI > 16). A total of 326 patients underwent CRS with HIPEC for CRPM. There were 39 patients (12%) with High Volume disease, and 15 of these (38%) received NAC. Patients with High Volume disease had significantly longer operating time, lower likelihood of complete macroscopic cytoreduction (CC-0 score), longer intensive care unit length of stay and longer hospital stay compared to Low Volume disease. In High Volume disease, the NAC group had a significantly shorter median survival of 14.4 months compared to 23.8 months in the non-NAC group (p = 0.046). Patients with High Volume CRPM achieved good median survival following CRS with HIPEC, which challenges the current PCI threshold for offering CRS. The use of NAC in this cohort did not increase perioperative morbidity but was associated with significantly shorter median survival compared to upfront surgery.

Impact of neoadjuvant chemotherapy on the safety and long-term outcomes of patients undergoing immediate breast reconstruction after mastectomy

BackgroundIn breast cancer patients receiving neoadjuvant chemotherapy (NAC), immediate breast reconstruction (IBR) as a breast cancer treatment option remains controversial. We assessed the impact of NAC on surgical and oncological outcomes of patients undergoing IBR.MethodsThis was a retrospective multicenter study of 4726 breast cancer cases undergoing IBR. The rate of postoperative complications and survival data were compared between IBR patients who received NAC and those who did not receive NAC. Propensity score matching analysis was performed to mitigate selection bias for survival.ResultsOf the total 4726 cases, 473 (10.0%) received NAC. Out of the cases with NAC, 96 (20.3%) experienced postoperative complications, while 744 cases (17.5%) without NAC had postoperative complications. NAC did not significant increase the risk of complications after IBR (Odds ratio, 0.96; 95%CI 0.74–1.25). At the median follow-up time of 76.5 months, 36 patients in the NAC group and 147 patients in the control group developed local recurrences. The 5-year local recurrence-free survival rate was 93.1% in the NAC group and 97.1% in the control group. (P < 0.001). After matching, there was no significant difference between the two groups.ConclusionIBR after NAC is a safe procedure with an acceptable postoperative complication profile.

Neoadjuvant chemoimmunotherapy confers survival advantage for patients undergoing sleeve lobectomy.

It has been demonstrated that neoadjuvant immune checkpoint inhibitor (ICI) plus chemotherapy was safe and feasible referred to neoadjuvant chemotherapy for patients with non-small cell lung cancer undergoing sleeve lobectomy. Nevertheless, no survival data were reported in the previous researches. Therefore, we conducted this study to compare neoadjuvant ICI plus chemotherapy versus neoadjuvant chemotherapy followed by sleeve lobectomy for long-term survival outcomes. Patients who underwent bronchial sleeve lobectomy following neoadjuvant ICI plus chemotherapy or neoadjuvant chemotherapy were retrospectively identified. Treatment response, perioperative outcomes, event-free survival and overall survival were compared between groups in the overall and the inverse probability of treatment weighting-adjusted cohort. A total of 139 patients with 39 lung cancer recurrence and 21 death were included. Among them, 83 (59.7%) and 56 (40.3%) patients received neoadjuvant chemotherapy and neoadjuvant ICI plus chemotherapy, respectively. After inverse probability of treatment weighting, more patients achieved complete pathological response in the neoadjuvant ICI plus chemotherapy group (6.0% vs 26.3%, P < 0.001). There was no significant difference regarding overall postoperative complication (23.8% vs 20.2%, P = 0.624) and specific complications (all P > 0.05). Patients receiving neoadjuvant ICI plus chemotherapy had favourable event-free survival (hazard ratio 0.37, 95% confidence interval 0.16-0.85, P = 0.020) and overall survival (hazard ratio 0.23, 95% confidence interval 0.06-0.80, P = 0.021). Multivariable analysis revealed that neoadjuvant ICI plus chemotherapy was an independent predictor for favourable event-free survival (hazard ratio 0.37, 95% confidence interval 0.15-0.86, P = 0.020, adjusted for clinical TNM stage). Neoadjuvant ICI plus chemotherapy was correlated with favourable long-term survival in patients with non-small cell lung cancer undergoing sleeve lobectomy.

Influence of Neoadjuvant Immunotherapy-Chemotherapy on Perioperative Outcomes in Locally Advanced Esophageal Adenocarcinoma.

This study evaluated the perioperative outcomes for patients who had locally advanced esophageal adenocarcinoma (EAC) treated with neoadjuvant immunotherapy (IO) and chemotherapy versus a matched cohort of patients who received neoadjuvant chemotherapy (NAC) alone. A single-center non-randomized phase 2 trial was undertaken with locally advanced (cT3-4 and/or N+) EAC, and 49 patients completed neoadjuvant avelumab + docetaxel, cisplatin, 5FU (DCF) and esophagectomy between February 2018 and February 2020. These patients were matched with contemporary patients (January 2018 to June 2020) who met the inclusion criteria but received neoadjuvant chemotherapy alone (NAC) with a comparable docetaxel-based therapy. The postoperative outcomes then were compared between the two groups. For this study, 99 patients with locally advanced EAC underwent esophagectomy and met the enrolment criteria. Of these patients, 50 received NAC alone and 49 received IO + NAC. Baseline characteristics such as age, gender, and clinical stage were comparable between the two groups. Operative approach and rate of minimally invasive esophagectomy (~ 60%) were similar in the two groups. For the NAC-alone and IO + NAC groups, the respective overall and major complication rates were similar between the two groups (50% vs. 51% [p = 0.91] and 20% vs. 26% [p = 0.44], respectively), with concordant rates for anastomotic leak (6 [12%] vs. 6 [12%]; p = 0.86) and respiratory complications (13 [26%] vs. 11 [22%]; p = 0.68). The two groups did not differ significantly in terms of hospital length of stay or 30- and 90-day mortality rates. The addition of immunotherapy to neoadjuvant chemotherapy for locally advanced esophageal adenocarcinoma does not appear to alter perioperative short-term outcomes significantly after esophagectomy.

Abstract 6433: Anti-CD36 monoclonal antibody can sensitize the neoadjuvant chemotherapy response in PDAC by eliminating the senescent tertiary lymphatic structure

Abstract Objective: Pancreatic ductal adenocarcinoma (PDAC) is deadly and aggressive. Neoadjuvant chemotherapy (NAC) may reduce tumor volume and alter the resectability of the tumor. The efficacy of neoadjuvant chemotherapy in patients is still limited. Tertiary lymphoid structures (TLSs) develop in peripheral non-lymphoid tissues and are essential for the immune response and correlate with chemotherapy in various tumor types. However, more research is needed to determine how TLSs affect neoadjuvant chemotherapy in PDAC. We aim to determine how neoadjuvant chemotherapy affects tumor-infiltrating lymphocytes (TLSs) in PDAC patients. We also want to find a biomarker to boost PDAC neoadjuvant chemotherapy response. Methods: We retrospectively collected formalin-fixed paraffin embedded (FFPE) tissues from 115 PDAC patients without preoperative treatment and 72 patients pretreated with neoadjuvant chemotherapy. Multispectral images were processed using AI-powered image analysis software (Tissue Gnostics; Zeiss, Germany). The 10X Genomics platform was used to sequence single cells in tissue samples from five patients who received neoadjuvant chemotherapy (NAC) and five patients who had not received any treatment before analysis (pretreatment naïve, PN). TLS was separated using Laser Microdissection. The mouse model was created by orthotopically injecting tumor cells into the pancreas. Results: Patients who received NAC have a senescent microenvironment. High-throughput single-cell sequencing showed that the senescent gene signature score was enriched in the NAC group, especially in immune cells. The percentage of p16+ CD20+ B cells and P16+ CD3+ T cells in TLSs also increased in the NAC group. Spatial transcriptomics analysis exhibited that CD36 is highly expressed in senescent TLSs, which suggested that CD36 may be a marker for senescent TLSs. Moreover, CD36+ TLSs induced the infiltration of MDSCs and regulatory T cells. CD36+ TLSs were an independent prognostic factor for poor overall survival (OS) (HR=0.67, p=0.002) and progression-free survival (PFS) (HR=0.71, p=0.003). A mice orthotopic xenograft model showed that an anti-CD36 monoclonal antibody eliminated senescent TLSs in pancreatic tissue. MDSCs and Tregs in the surrounding tissue also decreased. Additionally, in vivo KPC mice model showed that the combination of an anti-CD36 and chemotherapy reduced tumor volume and increased survival compared to chemotherapy alone. Conclusion: NAC has the potential to induce the senescence of tumor-associated TLSs, a phenomenon that has been linked to unfavorable prognosis in PDAC. CD36 serves as a viable marker for senescent TLSs that can be targeted. The administration of an anti-CD36 monoclonal antibody can potentially enhance the efficacy of chemotherapy in PDAC by selectively eliminating CD36+ senescent TLSs in mouse models. Citation Format: Jingrui Yan, Tianxing Zhou, Chao Yang, Yongjie Xie, Jun Yu, Jihui Hao. Anti-CD36 monoclonal antibody can sensitize the neoadjuvant chemotherapy response in PDAC by eliminating the senescent tertiary lymphatic structure [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6433.

Factors associated with engraftment success of patient-derived xenografts of breast cancer

BackgroundPatient-derived xenograft (PDX) models serve as a valuable tool for the preclinical evaluation of novel therapies. They closely replicate the genetic, phenotypic, and histopathological characteristics of primary breast tumors. Despite their promise, the rate of successful PDX engraftment is various in the literature. This study aimed to identify the key factors associated with successful PDX engraftment of primary breast cancer.MethodsWe integrated clinicopathological data with morphological attributes quantified using a trained artificial intelligence (AI) model to identify the principal factors affecting PDX engraftment.ResultsMultivariate logistic regression analyses demonstrated that several factors, including a high Ki-67 labeling index (Ki-67LI) (p < 0.001), younger age at diagnosis (p = 0.032), post neoadjuvant chemotherapy (NAC) (p = 0.006), higher histologic grade (p = 0.039), larger tumor size (p = 0.029), and AI-assessed higher intratumoral necrosis (p = 0.027) and intratumoral invasive carcinoma (p = 0.040) proportions, were significant factors for successful PDX engraftment (area under the curve [AUC] 0.905). In the NAC group, a higher Ki-67LI (p < 0.001), lower Miller-Payne grade (p < 0.001), and reduced proportion of intratumoral normal breast glands as assessed by AI (p = 0.06) collectively provided excellent prediction accuracy for successful PDX engraftment (AUC 0.89).ConclusionsWe found that high Ki-67LI, younger age, post-NAC status, higher histologic grade, larger tumor size, and specific morphological attributes were significant factors for predicting successful PDX engraftment of primary breast cancer.

Preliminary results of surgical treatment and neoadjuvant chemotherapy in upper rectal cancer

Introduction: There is a lack of information on the role of neoadjuvant chemotherapy in upper rectal cancer. The aim of our research was to investigate the role of neoadjuvant chemotherapy in upper rectal cancer treatment.Materials and methods: We conducted a retrospective cohort multicenter study to analyze the medical records of patients with upper rectal cancer from 2007 to 2020 obtained from the archive of Research Institute FSBI «N. N. Blokhin Cancer Research Center» of the Ministry of Health of Russia, A. N. Ryzhikh National Medical Research Centre for Coloproctology, Stavropol regional Clinical oncological Dispensary and Kaliningrad oncological Center. All patients were divided into 2 groups: group 1 included patients who underwent neoadjuvant chemotherapy with CAPOX as the first treatment step, and group 2 included patients who underwent upfront surgery. Primary endpoint was 3‑year disease-free survival (DFS) rate. We also estimated the pathological complete response (pCR) rate, treatment toxicity, postoperative morbidity rate (Clavien – Dindo), degree of tumor regression, local recurrence rate, distant metastases rate, 3‑year overall survival (OS) and the neoadjuvant chemotherapy completion rate.Results: 118 patients were included in the neoadjuvant chemotherapy group and 103 patients — in the surgery group. Study groups were well balanced and comparable for gender, the ASA status and the tumor differentiation grade. More patients in the neoadjuvant chemotherapy group had clinically positive lymph nodes (p = 0.002). Median follow-up period was 36 months. There were no significant differences in 3‑year OS and DFS. The local recurrence rate was 3.9 % in the surgery group versus 0 % in the neoadjuvant chemotherapy group (p = 0.046). There were no significant differences between study groups in the distant metastases rate (p = 0.293). Sixteen (13.6 %) patients had a pCR after neoadjuvant chemotherapy. The neoadjuvant chemotherapy completion rate was 91.5 %. The hematological toxicity grade 3–4 was observed in 3.3 % (4 patients), the non-hematological toxicity grade 3–4 in 3.3 % (4 patients).Conclusion: NACT has an acceptable toxicity profile, does not impede oncological treatment results, and can be used in a selected group of patients for early systemic control.

Cytomorphological disparities in invasive breast cancer cells following neoadjuvant endocrine therapy and chemotherapy.

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. 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). 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. Post-treatment, KIF2A exhibited a decrease, with the magnitude of change being greater in the NAE group than in the NAC group. However, no discernible differences were found in caspase-9 expression between the two groups. 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.