Chemotherapy For Breast Cancer Research Articles

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

Predicting pathological response in early-stage triple-negative breast cancer: Exploring the role of BRCA gene mutations—A retrospective single-institution study.

e12656 Background: Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer, constituting approximately 15-20% of all breast cancer cases. While less than 10% of all breast cancer patients harbor BRCA1/2 mutations, ~20% of TNBC patients carry these mutations. Notably, at least one-third of BRCA1 carriers develop TNBC. This study aimed to investigate the association between BRCA mutation status and pathological response (PR) in early-stage TNBC patients, specifically, the impact of BRCA positivity on achieving pathological complete response (pCR), and identify other potential predictors of PR. Methods: We conducted a retrospective cohort study of patients with early-stage (Stage I-III) triple-negative breast cancer diagnosed and treated at our institution between January 2012 and June 2022, following Institutional Review Board (IRB) approval. Patients were identified from our Institutional Cancer Registry based on complete data availability (including other inclusion criteria) excluding patients who did not receive neoadjuvant chemotherapy. Data on demographics, tumor characteristics, treatment regimens, and pathological response (assessed according to [specified criteria]) were extracted from the charts. Results: Out of 228 patients diagnosed with early-stage triple-negative breast cancer, 54.6% had no genetic mutations, while 7.9%, 4.9%, and 8.4% harbored BRCA1, BRCA2, and other mutations, respectively. Notably, 23.4% did not receive genetic counseling or testing at our institution. Patients with BRCA2 mutations had a 100% pathological response rate, of which 57.14% had pCR, compared to 85.7% for BRCA1, of which 71.43% had pCR. Furthermore, 93.8% of patients with other genetic mutations had pathological response, of which 56.25% had pCR, as compared to 68.42% in non-mutated cases of which 26.7% had pCR ( P=0.038). Analysis of other variables revealed no significant impact of age, BMI, performance status, or neoadjuvant chemotherapy regimen on pathological response. Conclusions: This retrospective study suggests a trend towards higher complete pathological responses in early-stage triple-negative breast cancer patients with BRCA and other genetic mutations compared to those without. These findings were statistically significant, indicating a potential clinical trend that specific genetic mutations may be associated with improved response to neoadjuvant chemotherapy in early-stage triple-negative breast cancer. Further research is needed to confirm these findings and guide the development of personalized treatment strategies based on a patient's genetic profile. Additionally, our findings highlight the importance of genetic testing for all patients with early-stage triple-negative breast cancer, regardless of age or family history.

Safety run-in phase of the multi-epitope HER2 peptide vaccine in combination with trastuzumab emtansine in HER2-positive breast cancer with residual disease after neoadjuvant chemotherapy.

550 Background: Residual disease after neoadjuvant chemotherapy (NAC) in HER2-positive breast cancer (BC) confers poor outcomes. Despite additional trastuzumab emtansine (T-DM1) in the adjuvant setting, a significant number of patients with residual disease still develop recurrence. H2NVAC is a multi-epitope T helper cell-activating peptide vaccine that is composed of 4 degenerate HER2-derived HLA-DR epitopes admixed with GM-CSF. Our previous phase I trial showed that this vaccine was safe and generated robust, long-lasting T and B cell immune responses. Methods: Patients with stage II-III HER2+ BC with any amount of residual disease in the breast /axilla after NAC were enrolled in a safety run-in phase of H2NVAC in combination with T-DM1. Patients were treated with H2NVAC and T-DM1 for 6 cycles, followed by 2 boosters at 3 and 12 months. Dose-limiting toxicity (DLT) was defined as any grade (G) ≥ 3 adverse events (AE) occurring within 21 days after the first vaccination. Results: A total of20 patients were enrolled with a median age of 51 years (range 27-69), 80% were White and 15% were Black. Most patients had hormone receptor-positive disease (90%). 40% were premenopausal, 40% were postmenopausal, and 20% were unknown. 14 patients had ypT1, 3 patients ypT2, 3 patients ypT3, 1 patient ypT4, 8 patients ypN0, 9 patients yp N1, 1 patient ypN1mi, and 2 patients ypN2. H2NVAC, in combination with T-DM1, was well tolerated, with no DLT being observed. Only grades 1 and 2 AEs were observed during the DLT period, with fatigue being the most common (G1 60%, G2 5%), followed by peripheral sensory neuropathy (G1 55%, G2 5%) and injection site reaction (G1 50%). Across all treatment cycles, the top 10 most common AEs that were at least possibly related to treatment include injection site reaction (G1 85%, G2 15%), AST increase (G1 65%), ALT increase (G1 45%), fatigue (G1 35%, G2 10%), peripheral sensory neuropathy (G1 35%, G-tube 10%), alk-phos increase (40% G1), nausea (G1 35%, G2 5%), arthralgia (G1 35%), myalgia (G1 25%, G2 5%), and platelet count decrease (G1 30%). There were four patients with G3 AEs at least possibly related to the vaccine observed after the DLT period, including allergic reaction, myositis/skin infection, urticaria, and pruritus/maculopapular rash. Conclusions: H2NVAC, in combination with T-DM1, was safe without DLT observed. The side effect profile was favorable, with the most common AE being the G1 injection site reaction. A multicenter, randomized, placebo-controlled, phase II trial of H2NVAC vs. placebo in combination with trastuzumab emtansine is currently ongoing through the ACCRU consortium. Clinical trial information: NCT04197687 .

Clinical outcomes of patients with HER2-positive microinvasive breast cancer.

544 Background: Although previous studies have reported that adjuvant trastuzumab with paclitaxel resulted in excellent survival outcomes in small, node-negative HER2-positive breast cancer, the necessity of adjuvant chemotherapy in HER2-positive microinvasive breast cancer (MIBC) remains controversial. Methods: Between January 2000 and January 2020, women with curatively resected pT1mi N0 and/or N1mi in Asan Medical Center were retrospectively identified and their survival outcomes including invasive disease-free survival (IDFS, excluding second primary cancer), distant recurrence-free survival (DRFS), and overall survival (OS) and the effect of adjuvant chemotherapy were analyzed. Results: A total of 833 patients were included. The median age was 51 years, and 51% (n = 426) were premenopausal. Pathologic nodal stage was pN0 in 96% (n = 799) and pN1mi in 0.7% (n = 6), and estrogen receptor (ER) was positive in 30% (n = 247). Adjuvant chemotherapy was administered to 18% (n = 147) of patients, of which 95% were fluorouracil-based. Six patients (0.7%) received adjuvant trastuzumab. With the median follow-up of 118.7 months, the 8-year IDFS and DRFS rates were 90.6% (95% CI, 88.4-92.7), and 97.3% (95% CI, 96.1-98.4), respectively, and the 8-year OS were 98.6% (95% CI, 97.8-99.5). IDFS did not differ by adjuvant chemotherapy, as the 8-year IDFS rates for patients who did and did not receive adjuvant chemotherapy were 91.1% (95% CI, 86.6-95.8) and 90.3% (95% CI, 87.9-92.8), respectively ( p = 0.930). The lack of differences in IDFS by chemotherapy was consistent across subgroups including pre-/postmenopausal patients, grade 1-2/3 tumors, and ER-negative diseases. Conclusions: In HER2-positive MIBC, a clinically meaningful proportion of patients experience IDFS events with long-term follow-up. The role of modern adjuvant chemotherapy regimens, as well as the role of adjuvant trastuzumab, should be further explored in this early-stage patient population.

Association of germline polygenic risk for thyroid autoimmunity with overall survival in the I-SPY2 Trial.

10600 Background: Germline genetic variation influences immune activity and risk of autoimmunity, and has been hypothesized to play a role in response to cancer therapeutics and survival. Prior studies of breast cancer have reported associations between genetic variation in thyroid autoimmunity and overall survival (OS). Here, we aim to investigate the association between a polygenic risk score for hypothyroidism (PRS-H) and response to therapy in women with early-stage breast cancer, and hypothesize that high PRS-H will be associated with better treatment response and survival. Methods: This study includes 1,368 women aged 18 years and above with stage II-III breast cancer of size > 2.5cm by clinical exam, with germline data available. It is an approved biomarker analysis of the I-SPY 2 trial, which is a phase II, adaptive, randomized platform trial across multiple sites studying novel cancer therapeutics across multiple arms for use as neoadjuvant chemotherapy for early-stage breast cancer. The outcome of survival is defined as alive at the most recent follow-up. Using the Cox proportional hazards model, we evaluate the association between a previously published PRS-H and overall survival. Models are adjusted for age at screening, immunotherapy status, and five principal components. Results: Among 1,368 early-stage breast cancer women, 33% (n=447) had pCR, and 85% (n=1,157) were alive at the last follow-up. Additionally, 16% (n=219) of women received immunotherapy. We observe a significant association between PRS-H and OS (HR = 0.78, 95% CI 0.66-0.92, p=0.004). Individuals in the top 10th percentile of the PRS-H (highest genetic risk) have improved survival (log rank p=0.04). Conclusions: Germline genetic variation in thyroid autoimmunity proclivity is associated with improved overall survival in our cohort of women with early-stage breast cancer receiving neoadjuvant chemotherapy. Our findings suggest that the genetic risk for autoimmunity may be important for long-term survival. We will expand this analysis to include the entire I SPY 2 population when all patients have completed genotyping. We plan to further characterize the role of germline autoimmunity profiles and survival. Clinical trial information: NCT01042379 .

Assessing the feasibility and cost-effectiveness of all oral adjuvant chemotherapy (cyclophosphamide, methotrexate, capecitabine) in high-risk hormone receptor positive breast cancer.

TPS616 Background: Women with high-risk HR+/HER2- breast cancer (BCA) receive additional chemotherapy to reduce disease recurrence. Preferred Taxane and Anthracycline based chemotherapy regimens have debilitating side effects such as cardiotoxicity, leukemia, peripheral neuropathy, severe fatigue, alopecia, downtime which are more common in black women thereby necessitating dose reductions. Metronomic cyclophosphamide, methotrexate, 5-fluourouracil (CMF) is an option but less preferred due to frequent dosing and longer therapy duration. Head-to-head comparison of CMF to anthracycline-based chemotherapy conducted 3 decades ago in early-stage BCA showed anthracycline benefit was driven by HER2+ disease with no benefit for HR+/HER2- BCA. Head-to-head comparison trials of CMF and Taxane-based regimen have not been conducted but single institution data suggest similar disease-free and similar overall survival but different toxicity profiles favoring CMF. In our ongoing trial, we converted all three chemotherapy drugs in CMF regimen to an all-oral regimen namely oral Cyclophosphamide, oral Methotrexate, oral Capecitabine (CMC) with the potential benefit of increased patient convenience, decreased costs (oral agents are generic; no chair time; no growth factors), and improved toxicity profile (low rates of grade III neutropenia, no port complications, no alopecia). This trial in progress aims to evaluate the feasibility of oral CMC by measuring the relative dose intensity in addition to the safety and tolerability of oral CMC. We hypothesize that 80% of patients will receive >85% of the intended dose of oral CMC. Methods: This is a Phase II, single arm, non-randomized study enrolling 25 patients with high-risk early-stage HR+ HER2- breast cancer to receive oral CMC regimen based on dose conversion equivalent bioavailability with conventional metronomic CMF chemotherapy. Enrolled patients will receive adjuvant therapy of oral cyclophosphamide 60 mg/m2 PO days 1-21 continuously, Methotrexate 15 mg/m2 PO Day 1, 8, and 15 and Capecitabine 650 mg/m2 PO BID Day 1- 14 to be given every 21 days for 8 cycles. The primary objective is to assess feasibility which is defined as 80% of patients (greater than 20 patients) maintaining a relative dose intensity (RDI) > 85%. The RDI is calculated as the ratio of the actual dose intensity/standard dose intensity; the average RDI for oral CMC regimen is the sum of RDI for each drug divided by 3. This study will be stopped if >25% of patients report Grade 4+ toxicity on oral CMC. The secondary objectives will assess quality of life as reported by the patients and report adverse effects. Clinical trial information: NCT06085742 . [Table: see text]

Fulvestrant with or without the cyclin-dependent kinase 7 (CDK7) inhibitor samuraciclib in advanced hormone receptor positive (HR+) breast cancer after CDK4/6 inhibition: Phase II SUMIT-BC study.

TPS1126 Background: CDK7 enhances oncogene transcription and upregulates anti-apoptotic genes, accelerates the cell cycle via CDK phosphorylation, and activates estrogen receptors (ERs) that can drive resistance to hormonal therapy in cancer. CDK7 inhibition therefore represents a potential anticancer strategy in cancer. Samuraciclib (CT7001) is a small molecule, ATP competitive, selective oral inhibitor of CDK7 that inhibits these key effects of CDK7. Samuraciclib had a favorable safety profile and showed clinical activity when combined with fulvestrant in a phase I study in patients with HR+/HER2− advanced breast cancer (BC) who had previously been treated with a CDK4/6 inhibitor. Patients with no detectable TP53 mutation in ctDNA at baseline and those without baseline liver metastases appeared to have better outcomes. The instant release capsule formulation of samuraciclib used in this study released large amounts of samuraciclib high in the gastrointestinal (GI) tract, which may have contributed to the observed low grade GI adverse events, which were managed with prophylaxis and counselling (1). Methods: A phase 2 open-label randomized study has been designed to evaluate the efficacy, safety, pharmacokinetics (PK), and quality of Life (QoL) of samuraciclib combined with fulvestrant compared to fulvestrant monotherapy (SUMIT-BC; NCT05963984). Eligible patients (n=60) are ≥18 years, have histologically or cytologically confirmed ER+/HER2− advanced or metastatic BC not amenable to resection or radiotherapy of curative intent, have received an aromatase inhibitor combined with a CDK4/6 inhibitor in the adjuvant or advanced setting, are receiving a luteinizing hormone-releasing hormone agonist if pre/perimenopausal, and have RECIST v1.1 evaluable disease. Prior SERD, mTOR inhibition, or chemotherapy for advanced BC are not permitted. All patients undergo baseline Guardant360 ctDNA analysis to establish TP53 and other mutation status. Patients are randomized 1:1:1 to fulvestrant alone (500 mg IM administered on days 1, 15 and 29 and then monthly), fulvestrant and samuraciclib 240 mg QD, or fulvestrant and samuraciclib 360 mg QD. In preparation for phase 3 development, a novel single tablet formulation of samuraciclib is used, which may enhance GI tolerability. Patients undergo RECIST v1.1 evaluation at baseline, every 8 weeks until week 48, and every 12 weeks thereafter. The primary endpoint is clinical benefit response at 24 weeks. Secondary endpoints are tolerability, progression free survival, overall response rate, duration of response, and PK of fulvestrant and samuraciclib. QoL (Functional Assessment of Cancer Therapy - Breast questionnaire [FACT-B]) and correlations between TP53 mutation and efficacy/safety will be assessed. 1. Coombes et al. Nature Comms 2023. Clinical trial information: NCT05963984 .

Exosome-delivered microRNAs confer adriamycin-resistance through modulating the immune and metabolism-related gene PTEN in HER2-negative breast cancer.

e12500 Background: Anthracycline is widely used in breast cancer (BCa) chemotherapy, but acquired drug resistance remains a challenge. Increasing evidence suggests that changes in the tumour immune microenvironment (TIME) consistently contribute to the development of chemoresistance. Methods: TIME scores and tumor-infiltrating immune cells (TICs) scores were used to investigate the prognosis, characteristics and gene transcriptomic profiling of HER2-negative BCa patients who received anthracycline chemotherapy. Exosomes from MCF/7-ADR (ADR-exos) and MCF/7-S cell lines were characterized. Dysregulated miRNAs were obtained by using miRNA microarray analysis on BCa cells and their corresponding exosomes. Protein profiling was performed to identify differentially expressed proteins in up- and down-regulated miR-222 cells. Ability of ADR-exos to transfer drug-resistance mediated by miR-222 was assessed by immunofluorescence assay and flow cytometry. Conditions to load miR-222 mimic or inhibitor into exosomes were optimized. Influence of miR-222 inhibitor-containing exosomes on the downstream pathway of miR-222 and the potential therapeutic effects were evaluated. Relationship between miR-222/PTEN and drug resistance in circulating exosomes from mice after doxorubicin chemotherapy was investigated. Results: Firstly, we discovered the complicated and heterogeneous TICs subtypes and their unique biological behaviors in HER2-negative BCa. Then, we identified 85 differentially expressed immunologic signature gene sets and 7202 corresponding immune-related genes in three subtypes quantified by gene set variation analysis. We identified 12 up-regulated and 13 down-regulated genes using miRNA microarray analysis in doxorubicin-resistant cells and their exosomes. Mass spectrometry found 45 differentially expressed proteins affected by miR-222. Moreover, we successfully established miRNA mimic/inhibitor-containing exosomes to explore the solo function of exosomal miR-222 in doxorubicin-resistance both in vitro and in vivo. For the first time, we detected the levels of miR-222 and its target gene PTEN in circulating exosomes from mice after doxorubicin-based chemotherapy and explored the potential clinical implications of miR-222/PTEN-containing exosomes in chemotherapy and immune suppression of BCa. Conclusions: Doxorubicin-resistant cells can transmit drug-resistance to sensitive cells via delivering miR-222 by modulating the immune- and metabolism-related gene PTEN without interference from other relevant drug-resistance factors in exosomes. Therefore, miR-222-containing exosomes and their target gene PTEN may be a promising biomarker for predicting chemotherapy efficacy and tumor immunity regulation in BCa patients receiving anthracycline chemotherapy.

Surgical decision-making after neoadjuvant chemotherapy for breast cancer.

e23282 Background: Following neoadjuvant chemotherapy (NAC), a significant subset of breast cancer patients become candidates for breast conserving surgery (BCS) after tumor downstaging. Studies have shown there is no survival advantage between BCS and mastectomy after NAC and that patient prognosis is largely predicted by the pathologic response to treatment. While the literature highlights many aspects of surgical decision-making in breast cancer, there is little analysis of patient choice after NAC. The goal of this study is to investigate clinical and demographic factors that may associate with patients’ surgical decision-making after receiving NAC as well as related outcomes. Methods: A retrospective chart review was conducted on breast cancer patients at our institution who became BCS candidates after receiving NAC from 1/1/2010 to 9/30/2020. Patient demographics, clinical characteristics, choice of mastectomy versus BCS, and outcomes were compared. Exclusion criteria included inflammatory, recurrent, and bilateral breast cancers, and patients with genetic predisposition. T-tests and chi-squared tests of association were used for continuous and categorical variables respectively. Survival outcomes were reported using the log-rank test. The p-value threshold for significance was p < 0.05. Statistical analysis was performed using R software version 4.2.3. Results: In this analysis, 244 patients met study criteria, of which 181 (74.2%) patients chose BCS and 63 (25.8%) patients elected mastectomy. Patients who chose mastectomy were younger at time of diagnosis than those who chose BCS: median age 48 years in mastectomy group versus 53 years in BCS group (p = 0.003). Regarding physical exam findings, while palpability of the primary breast tumor was not associated with choice of surgery (p = 0.271), presence of axillary lymphadenopathy was associated with a higher likelihood of choosing mastectomy (44.4% in mastectomy subgroup versus 29.3% in BCS subgroup, p = 0.041). Patient race, pre-treatment clinical stage, and doxorubicin-based chemotherapy were not associated with patients’ decisions for type of surgery. With respect to outcomes, follow-up time was similar between both groups with overall median of 5 years, and there was no significant difference in local or distant recurrence, and overall mortality (log-rank p = 0.3). Conclusions: The majority of breast cancer patients elect BCS after downstaging from NAC. Factors that are associated with choosing mastectomy include younger age at diagnosis and pre-treatment palpable axillary lymphadenopathy, which may be perceived as more advanced stage, despite no difference in stage between both groups. Regardless of surgical choice, both recurrence and mortality rates did not significantly differ between patients who chose BCS versus mastectomy, which is consistent with the literature.

Personalized circulating tumor DNA for minimal residual disease and dynamic assessment in patients undergoing neoadjuvant chemotherapy for breast cancer: Preliminary analysis from MSK-LINC.

3049 Background: Identification of minimal residual disease (MRD) with circulating tumor DNA (ctDNA) in pts with early-stage breast cancer holds promise to identify risk of relapse. MSK-LINC is prospective ctDNA plasma analysis of breast cancer pts. This pilot study evaluated the utility of serial ctDNA assessment as a biomarker for monitoring MRD and recurrence prediction in clinical stage II-III breast cancer pts undergoing neoadjuvant chemotherapy (NAC). Methods: 30 pts who underwent NAC across all subtypes were identified from MSK-LINC. The ctDNA analysis was performed at baseline, on-NAC, post-NAC/pre-surgery, within 8 weeks post-surgery, and during follow-up. Personalized ctDNA RaDaR assays were designed using whole exome sequencing data of paired primary tumor and germline samples from each pt. ctDNA levels were quantified as an estimated variant allele fraction (eVAF). Results: ctDNA panels were successfully designed for 29/30 pts (16 Stage II, 13 Stage III), including 6 HR+/HER2-, 12 HER2+, and 11 TNBC, with a median follow up of 4.2 years. The bespoke ctDNA assays targeted a median of 48 variants (21-51), with a median of 43 variants (11-48) passing quality control. A total of 175 plasma samples were analyzed, including 24 baseline and 24 post-surgery. A 100% ctDNA detection rate was observed at baseline in the 24 pts for whom a baseline sample was available (median eVAF 0.33%, range 0.0083% - 8.91%). Pathologic complete response (pCR) was achieved in 11 pts who remained disease free; and of the 18 pts without a pCR, 5 recurred. All patients with a pCR were ctDNA negative post treatment. In 3/5 patients who recurred, MRD detection was achieved, including one patient with persistent ctDNA positivity throughout all timepoints. For the other two pts, ctDNA was first detected in follow-up plasma collected at 4.4 and 9.8 months prior to clinical recurrence. Conclusions: This study demonstrates the potential of ctDNA as a dynamic biomarker for monitoring disease burden in pts with high-risk early-stage breast cancer, highlighting its remarkable sensitivity at baseline and its capability for MRD detection preceding clinical recurrence. These findings suggest the need for further research to fully understand the relationship between ctDNA dynamics during and after NACT with prediction of breast cancer outcomes. ctDNA detection rates in plasma samples across collection timepoints. [Table: see text]

Integrating 4 Methods (In4M) to evaluate physical function in patients with cancer: Results of a comprehensive digital health study.

1564 Background: Physical function (PF) is a core outcome in cancer trials that can inform treatment tolerability. PF can be assessed across modalities including by patient (pt) report, clinician (clin) report, performance tests and digital sensors. The optimal approach for PF measurement has not been defined. Methods: In4M is a prospective observational study evaluating PF in pts initiating chemotherapy for breast cancer or lymphoma followed over 9 months. We used an electronic platform (Hugo) to aggregate serially assessed pt-reported PF, clin- and pt-reported ECOG performance status (PS), 6-minute walk test (6MWT) and wearable (Fitbit) data. We evaluated feasibility in all pts; associations among PF measures and the ability of PF measures to detect change were evaluated in pts with both baseline (BL) and 3-month (3M) data. We used Pearson correlations to assess the relationship of average daily steps with measures of PF. To assess change, we compared each PF measure from BL to 3M using a 2-sided α=.05 paired t-test. Results: Of the208 pts enrolled, 193 (93%) and 159 (76%) completed surveys, and 121 (58%) and 124 (60%) provided wearable data (evaluable: ≥1 day data) at BL and 3M, respectively. When requiring a stringent BL with 4+ days of data with ≥1 weekend day to be evaluable, 88 (42%) and 120 (58%) provided wearable data at BL and 3M. At both BL and 3M, pt-reported PF was generally more highly correlated with wearable-derived daily steps than clin-reported PF and 6MWT were (Table). Significant declines in PF were observed for pt- and clin-reported PF (all p<0.05), but not other modalities. Conclusions: Longitudinalassessment of multi-modal PF data including pragmatic wearable data collection was feasible in pts receiving chemotherapy. Pt-reported PF was the only modality that was both correlated with step count and able to detect change. Additional wearable metrics, correlations among PF measurements and outcomes, and clinically meaningful change scores will be reported. Optimal PF measurement may improve future reporting of treatment tolerability. Clinical trial information: NCT05214144 . [Table: see text]

Patient factors associated with chemotherapy modifications: Results from the Optimal Breast Cancer Chemotherapy Dosing (OBCD) study.

520 Background: Understanding patient factors associated with an increased likelihood of receiving chemotherapy modifications is important for treatment planning and anticipating which patient groups might require extra support through the course of treatment. Methods: We have evaluated patient and tumor factors associated with chemotherapy modifications in a cohort of 9700 women receiving adjuvant chemotherapy for breast cancer at Kaiser Permanente Northern California (KPNC) and Kaiser Permanente Washington (KPWA) in the Optimal Breast Cancer Chemotherapy Dosing (OBCD) Study diagnosed between 2005-2019. The outcome variable, receipt of a ‘chemotherapy modification’ is defined as a composite representing any of the following deviations from the intended regimen: dose reduction >10% (first cycle or overall), extensive delay (any single delay >14 days), regimen change, or receipt of fewer cycles of any given drug than intended in the original chemotherapy plan. Multivariable-adjusted prevalence ratios (PR) and corresponding 95% confidence intervals (95% CI) were calculated using generalized linear models of the Poisson family with a log link-function and robust standard errors. Results: Several factors were associated with chemotherapy modifications. Notably, older age was associated with an increased likelihood of modifications (p-trend<0.001), with adults aged 80+ years at diagnosis 1.93-fold more likely to experience modification than adults 18-39 years (95% CI: 1.50-2.50). Increased comorbidity and BMI were also associated with increased likelihood of modification (p-trend for both:<0.001), with patients with a Charlson Comorbidity Index of 3+ (vs 0) having an PR of 1.33 (95% CI: 1.19-1.48) and those with a BMI of 35+ kg/m2 (vs <25 kg/m2) having an PR of 1.53 (95% CI: 1.41-1.65). HER2+ status (PR HER2+ vs HER2-: 1.99 95% CI: 1.89-2.10) and higher stage of disease (PR IIIA vs I:1.24; 95% CI: 1.13-1.35; p-trend<0.001) were associated with increased likelihood of chemotherapy modification, while hormone receptor positivity was associated with lower likelihood of modification (PR ER+ and/or PR+ vs ER-/PR-: 0.93; 95% CI: 0.88-0.99). Diagnosis in more recent years was also associated with decreased likelihood of modification (PR 2015-2019 vs 2004-2009: 0.70; 95% CI: 0.66-0.75), as was higher neighborhood income (PR Q4 vs Q1: 0.78; 95% CI: 0.72-0.84). Conclusions: Several patient-level and clinical factors were associated with chemotherapy modifications, including age, comorbidity, BMI, and ER/PR/HER2 status. Future research might focus on the groups noted to have increased risk of treatment modification to better understand the factors underlying these changes, as well as the impact on patient outcomes.

The protective effect of vitamin D on ovarian reserve and anti-mullerian hormone in patients undergoing chemotherapy for breast cancer, a randomized phase ΙΙ clinical trial.

Reduced ovarian reserve is among the crucial long-term side effects of using chemotherapy agents in breast cancer, yielding early ovarian failure. On the other hand, vitamin D is an essential factor in protecting the follicles and an important predictive factor for successful IVF therapy. The aim of this study is evaluation of vitamin D as a agent that can reduce fertility complications of chemotherapy specially in young women. Breast cancer patients undergoing chemotherapy at two cancer institutes were enrolled in this study. The case group received 1000 IU of calcitriol, and the AMH level was measured at the baseline, after chemotherapy, and six months after chemotherapy. The primary end point was improvement in the AMH level after six months of chemotherapy. the secondary endpoint was to evaluate the predictive factors of AMH level decline during chemotherapy. Between 2018 and 2019, 18 and 15 patients were enrolled in the case and control groups, respectively. The mean AMH level (ngr/ml) of the patients in the case and control group were 3.16 and 2.37 ng/mL, respectively (p-value = .16). These levels were 0.387 and 0.19 after six months (p-value = .38). The AMH rise immediately after chemotherapy cycles to six months after chemotherapy, in the case and control groups were 0.86 and 0.44 ng/mL, respectively, which was slightly higher in the case group but not statistically significant between two groups (p-value = .054). Despite a minimal rise in the AMH level after six months of chemotherapy, the study could not demonstrate any protective effect of vitamin D on patients' ovarian reserve undergoing chemotherapy for breast cancer. Further larger studies are needed to evaluate the effect of vitamin D supplements on ovarian reserve beside optimal dose and duration.

Trends and outcomes in patients receiving neoadjuvant chemotherapy for breast cancer in Ontario: A population-based study.

e12664 Background: Modern neoadjuvant chemotherapy (NAC) regimens in breast cancer offer higher rates of pathologic complete response, an ability to guide further adjuvant treatment, and may de-escalate surgery. However, the utilization of NAC has been heterogeneous in Ontario. This study aimed to describe trends in NAC use in Ontario, report survival outcomes, and explore factors associated with overall survival in these patients. Methods: This was a population-based cohort study using linked health administrative data in Ontario, Canada. From the Ontario Cancer Registry, we identified women ≥18 years who underwent neoadjuvant chemotherapy followed by surgery for operable (cT1N1, cT2-3N0, or cT2-3N1) breast cancer between 2012 and 2020. Patients were divided by receptor subtype (triple negative breast cancer [TNBC], ER+/HER2-, ER+/HER2+, ER-/HER2+) and characteristics were compared using standardized mean differences (SMDs). Five-year overall survival (OS) and breast cancer-specific survival (BCSS) were determined and reported for each subtype. Associations with OS and BCSS were calculated for patient and disease characteristics using univariate and multivariable Cox proportional hazards models and Fine and Gray models, respectively. Results: 3,804 women underwent NAC for cT1N1, cT2-3N0, or cT2-3N1 breast cancer in Ontario between 2012 and 2020. The largest contributing subtype was ER+/HER2- patients (39.3%) followed by those with HER2+ disease (ER-/HER2+ 13.8%, ER+/HER2+ 23.4%), and TNBC (23.5%). The median age was 50 years (IQR 42-59 years). Most patients were clinically node-positive (2,736; 71.9%), and underwent mastectomy (2,397; 63.0%). There was a significant increase in the number of patients receiving NAC in Ontario, from 217 in 2012 to 667 in 2019 ( p<0.001), with a greater increase among patients with TNBC or HER2+ disease. Compared to those with ER+/HER2- disease, TNBC patients were treated for smaller tumours (28.6% T3 vs. 39.8%; SMD = 0.24), and were more likely to be node-negative (39.1% N0 vs. 22.1%; SMD = 0.38). Similar trends for nodal status were found for patients with ER-/HER2+ (26.7% N0) and ER+/HER2+ cancer (27.9% N0). 5-year OS for the entire cohort was 88.1% (95% CI 87.1 – 89.2%). Survival was highest for ER+/HER2+ patients (94.2%, 95% CI 92.6 – 95.8%) and lowest for TNBC patients (80.1%, 95% CI 77.5 – 82.8%). Similar patterns were seen for BCSS. Factors associated with OS in a multivariable model included older age (increase in 5 years HR 1.1, 95% CI 1.07 – 1.14), N1 status (HR 1.99, 95% CI 1.61 – 2.47), larger tumour size (T3 HR 1.83, 95% CI 1.34 – 2.5), mastectomy (HR 1.45, 95% CI 1.2 – 1.75), and TNBC (versus ER+/HER2- HR 1.9, 95% CI 1.56 – 2.32). Conclusions: The use of NAC has increased in Ontario, particularly among TNBC and HER2+ patients. Women with TNBC have worse outcomes compared to those with ER+/HER2- disease, despite being treated for less advanced disease.

Radar reflectors for marking of target lymph nodes in patients receiving neoadjuvant chemotherapy for breast cancer: A subgroup analysis of the prospective AXSANA (EUBREAST-03) trial.

Radar reflectors for marking of target lymph nodes in patients receiving neoadjuvant chemotherapy for breast cancer: A subgroup analysis of the prospective AXSANA (EUBREAST-03) trial.

Application of multidisciplinary team model based on full-course management in health promotion of patients with breast cancer.

e13546 Background: To explore the application effectiveness of the multidisciplinary team model based on full-course management, in advancing the health promotion of breast cancer patients. Methods: This research involved a cohort of 84 breast cancer patients, recruited from the First Affiliated Hospital of Nanjing Medical University, spanning December 2022 and June 2023. These participants were divided into a control group and an intervention group using a convenience sampling method. The control group accepted routine nursing care, while the intervention group was treated with the multidisciplinary team approaches based on full-course management. These approaches included informal pre-admission interventions and multi-dimensional improvements to peri-operative patient comfort, integrated regimens combining Chinese and Western medicine to alleviate chemotherapy complications, diversified and extended nursing care focused on improving patients' quality of life, and facilitating physical and psychological rehabilitation. The two groups of patients were evaluated in satisfaction, comfort, quality of life, psychological state and other aspects. The results were evaluated by self-made satisfaction scale, breast cancer complications during chemotherapy questionnaire, Kolcaba Comfort Scale, Quality of Life Scale (QLQ-C30), self-rating Anxiety Scale (SAS) and self-rating Depression Scale (SDS). Patient outcomes were assessed in terms of satisfaction, comfort, quality of life, and psychological state. The results were evaluated by the self-made satisfaction scale, the breast cancer chemotherapy complications questionnaire, the Kolcaba Comfort Scale, the Quality of Life Scale (QLQ-C30), the Self-Rating Anxiety Scale (SAS), and the Self-Rating Depression Scale (SDS). Results: The intervention group showed statistically significant improvements in patient satisfaction, comfort and quality of life scores compared to the control group (P<0.05). Additionally, they exhibited a lower incidence of chemotherapy complications, severe anxiety and depression during the extended care period (P<0.05). Conclusions: The multi-disciplinary team model based on the full-course management demonstrated significant clinical benefits in the application of the full-course management of breast cancer patients. It effectively reduced chemotherapy-related complications, improved peri-operative comfort, decreased the incidence of severe anxiety and depression during the period of extended care, improved the physical and mental well-being of patients, leading to greater satisfaction and an enhanced quality of life.

Patient characteristics associated with primary prophylactic granulocyte colony-stimulating factor (G-CSF) use among women treated for early-stage breast cancer.

e12605 Background: The National Comprehensive Cancer Network (NCCN) recommends several chemotherapy regimens for early-stage breast cancer that have elevated risk of neutropenia (>20%). In these regimens, primary prophylactic use of granulocyte colony-stimulating factor (G-CSF) is recommended. Little is known about how patient-level factors relate to receipt of prophylactic G-CSF among women receiving these regimens. Methods: In the Optimal Breast Cancer Chemotherapy Dosing (OBCD) Study, we examined use of G-CSF among women with stage I-IIIA breast cancer between 2005-2019 in Kaiser Permanente Northern California (KPNC) and Kaiser Permanente Washington (KPWA). We evaluated the patient-level factors associated with primary prophylactic G-CSF use (≤7 days before to ≤3 days after first day of chemotherapy) among women receiving chemotherapy regimens with high risk of neutropenia, for which the NCCN guidelines recommend prophylactic G-CSF use. Multivariable-adjusted prevalence ratios (PR) and their corresponding 95% Confidence Intervals (95% CI) were calculated using generalized linear models of the Poisson family with a log link-function and robust standard errors. Results: Overall, while all 3,083 women receiving these regimens ultimately received G-CSF, 2412 (79%) received primary prophylactic G-CSF within the period 7 days prior to 3 days post first cycle. Younger women had higher prevalence of prophylactic G-CSF receipt (82.7% in ages 18-39 years vs. 58.1% in 70+ years). Black women had higher prevalence of receipt compared to white women (82.7% in non-Hispanic Black women vs 76.1% in White women). Women with a higher body mass index (BMI) had lower prevalence of receipt compared to normal weight women (73.3% in 35+ kg/m2 group vs 81.5% in 18.5-<25 kg/m2 group). In multivariable models, older women were less likely to receive prophylactic G-CSF (PR70+ vs 18-39: 0.69; 95% CI: 0.57-0.84; p-trend<0.001), as were those with a higher BMI (PRBMI 35+ vs 18.5-<25: 0.92; 95% CI: 0.85, 0.97; p-trend=0.006), and a later year of diagnosis (PR2016-19 vs 2005-07: 0.81; 95% CI: 0.77, 0.85; p-trend<0.001). Although race/ethnicity was not significantly associated with receipt of prophylactic G-CSF use overall in multivariable models, we observed Non-Hispanic Black women to experience slightly higher likelihood of G-CSF receipt than Non-Hispanic White women (PR: 1.08; 95% CI: 1.02, 1.15). Conclusions: Women of older age and those with higher BMI were less likely to receive primary prophylactic G-CSF, as were women treated in later years. Further research looking at timing of G-CSF use is warranted, as are studies examining provider/facility-level factors in relation to patterns of G-CSF use, G-CSF’s impact on survival outcomes, and the real-world impact of decisions around G-CSF use across age, BMI, and racial/ethnic groups.

Relationship between Tumor Infiltrating Lymphocytes and Neoadjuvant Chemoterapy Responsiveness: A Cross-Sectional Study on Breast Cancer Patients

Breast cancer is still a significant health problem in the world, with chemotherapy as an essential component in its management. Limited research on tumor- infiltrating lymphocytes (TIL) as a biomarker for the effectiveness of breast cancer treatment was conducted and is still contradictory. This study aims to investigate the relationship between TILs and the clinical response to neoadjuvant chemotherapy in breast cancer. The research used a cross-sectional study on eligible breast cancer patients in Wahidin Sudirohusodo Hospital in Makassar. TIL levels were grouped based on the histopathological examination results of breast tissue samples into three categories: low (0% to 10%), medium 15% to 50% and high (55% to 100%). Responsiveness was assessed based on changes in tumor size after neoadjuvant chemotherapy. The Chi-Square test is the primary analysis in this study. Results of 40 participants, the sample had a median age of 40 (27-73 years), mainly in the clinical stage III (40.0%), had moderate TIL concentration (47.5%), and was responsive to the neoadjuvant chemotherapy (87.5%). There was no significant association between TIL concentration and chemotherapy responsiveness (p > 0.05). However, in post-chemotherapy conditions, the median value of tumor size in the group with the high TIL category was significantly lower than in the low and medium TIL groups (p=0.034). There was no association between TIL levels and the clinical response to neoadjuvant chemotherapy in breast cancer patients. Further research is needed to confirm these findings.

Emulation and evaluation of tumor cell combined chemotherapy in isotropic/anisotropic collagen fiber microenvironments.

The rapid emergence of anisotropic collagen fibers in the tissue microenvironment is a critical transition point in late-stage breast cancer. Specifically, the fiber orientation facilitates the likelihood of high-speed tumor cell invasion and metastasis, which pose lethal threats to patients. Thus, based on this transition point, one key issue is how to determine and evaluate efficient combination chemotherapy treatments in late-stage cancer. In this study, we designed a collagen microarray chip containing 241 high-throughput microchambers with embedded metastatic breast cancer cell MDA-MB-231-RFP. By utilizing collagen's unique structure and hydromechanical properties, the chip constructed three-dimensional isotropic and anisotropic collagen fiber structures to emulate the tumor cell microenvironment at early and late stages. We injected different chemotherapeutic drugs into its four channels and obtained composite biochemical concentration profiles. Our results demonstrate that anisotropic collagen fibers promote cell proliferation and migration more than isotropic collagen fibers, suggesting that the geometric arrangement of fibers plays an important role in regulating cell behavior. Moreover, the presence of anisotropic collagen fibers may be a potential factor leading to the poor efficacy of combined chemotherapy in late-stage breast cancer. We investigated the efficacy of various chemotherapy drugs using cell proliferation inhibitors paclitaxel and gemcitabine and tumor cell migration inhibitors 7rh and PP2. To ensure the validity of our findings, we followed a systematic approach that involved testing the inhibitory effects of these drugs. According to our results, the drug combinations' effectiveness could be ordered as follows: paclitaxel + gemcitabine > gemcitabine + 7rh > PP2 + paclitaxel > 7rh + PP2. This study shows that the biomimetic chip system not only facilitates the creation of a realistic in vitro model for examining the cell migration mechanism in late-stage breast cancer but also has the potential to function as an effective tool for future chemotherapy assessment and personalized medicine.

Comprehensive analysis of plasma methylome reveals distinct patterns of methylation changes between responders and non-responders to neoadjuvant chemotherapy in breast cancer

The potential of cell-free DNA (cfDNA) methylation profiling in oncology is increasingly recognized for its ability to offer a comprehensive assessment of tumor biology. In this report, we explore the plasma methylome dynamics in patients with early breast cancer (BC) undergoing neoadjuvant chemotherapy (NACT) using an agnostic genome-wide approach with cell-free DNA immunoprecipitation and sequencing (cfMeDIP-seq). Our cohort comprised seven women with triple-positive BC, assessed for cfDNA methylation changes at multiple time points during their treatment course. Genome-wide analysis revealed distinctive patterns of differential methylation in patients achieving pathological complete response (pCR), with no significant epigenomic modifications in patients with residual disease (RD). Gene set enrichment analysis highlighted dynamic variations in functional pathways associated with therapy response, including metabolism, immune response, and response to xenobiotics, with a notable reversibility post-treatment. Principal component analysis of the differentially methylated regions demonstrated a clear distinction between pCR and RD patients, indicating the potential of cfMeDIP-seq for the non-invasive assessment of therapy response. Such findings suggest that cfMeDIP-seq could complement ctDNA offering broader insights into the global modifications induced by chemotherapy. Although future research is needed to validate and expand on our findings, we offer a proof-of-principle of the potential utility of cfMeDIP-seq in the personalized management of BC.