Efficacy In Breast Cancer Research Articles

BRD4-directed super-enhancer organization of transcription repression programs links to chemotherapeutic efficacy in breast cancer

BRD4 is well known for its role in super-enhancer organization and transcription activation of several prominent oncogenes including c-MYC and BCL2 As such, BRD4 inhibitors are beingpursued as promising therapeutics for cancer treatment. However, drug resistance also occurs for BRD4-targeted therapies. Here, we report that BRD4 unexpectedly interacts with the LSD1/NuRD complex and colocalizes with this repressive complex on super-enhancers. Integrative genomic and epigenomic analyses indicate that the BRD4/LSD1/NuRD complex restricts the hyperactivation of a cluster of genes that are functionally linked to drug resistance. Intriguingly, treatment of breast cancer cells with a small-molecule inhibitor of BRD4, JQ1, results in no immediate activation of the drug-resistant genes, but long-time treatment or destabilization of LSD1 by PELI1 decommissions the BRD4/LSD1/NuRD complex, leading to resistance to JQ1 as well as to a broad spectrum of therapeutic compounds. Consistently, PELI1 is up-regulated in breast carcinomas, its level is negatively correlated with that of LSD1, and the expression level of the BRD4/LSD1/NuRD complex-restricted genes is strongly correlated with a worse overall survival of breast cancer patients. Together, our study uncovers a functional duality of BRD4 in super-enhancer organization of transcription activation and repression linking to oncogenesis and chemoresistance, respectively, supporting the pursuit of a combined targeting of BRD4 and PELI1 in effective treatment of breast cancer.

Biomarkers of everolimus efficacy in breast cancer therapy

Everolimus is an inhibitor of serine/ threonine kinase mTOR. The drug is approved for the treatment of metastatic ER positive, HER2 negative breast cancers and benefits a subset of patients with these breast cancers in combination with hormonal therapies. Despite extensive efforts, no additional predictive biomarkers to guide therapeutic decisions for everolimus have been introduced in clinical practice. This paper discusses predictive biomarkers for everolimus efficacy in breast cancer. A search of the medline and web of science databases was performed using the words "everolimus" and "biomarkers". References of retrieved articles were manually scanned for additional relevant articles. Everolimus benefits a subset of patients with metastatic ER positive, HER2 negative breast cancers in combination with hormonal therapies. Despite extensive efforts no additional predictive biomarkers to guide therapeutic decisions for everolimus therapy have been confirmed for use in clinical practice. However, promising biomarker leads for everolimus efficacy in breast cancer have been suggested and include expression of proteins in the mTOR pathway in ER positive, HER2 negative breast cancers. In HER2 positive cancers PIK3CA mutations, and PTEN expression loss are prognostic. Other clinical predictive biomarkers with more limited data include characteristics derived from whole genome sequencing, subsets of circulating leukocytes and changes in Standardized Uptake Values (SUV) of Positron Emission Tomography (PET) scans. Putative predictive biomarkers for everolimus efficacy in breast cancer patients, both genomic and clinical, deserve further study and could lead to a better selection of responsive patients.

Sentinel Lymph Node Biopsy Efficacy in Breast Cancer: A 4-year Experience Report

Sentinel lymph node biopsy has been one of the most important advances in oncologic surgery, especially in breast cancer, since it decreases the high morbidity associated with radical axillary dissection, and allows treatment personalization. The staging of axillary nodes in breast cancer is fundamental as it is a prognostic indicator and determines the need for adjuvant therapy. Sentinel lymph node is detected by injecting a radioisotope and dye through the periareolar area that consequently travels through mammary glands to axillary lymph nodes. We conducted a retrospective study that included 57 women with a histopathological diagnosis of breast cancer, and underwent sentinel node biopsy. Transoperative pathology analysis reported metastases in 24% of the patients, requiring radical axillary dissection. Sensitivity was 97%, and specificity was 85%, reflecting high efficacy of the sentinel lymph node biopsy, and thus benefitting patients by decreasing morbidity. Sentinel node biopsy is the standard procedure for correct staging of patients with early breast cancer, and no clinical evidence of lymph node involvement. Further, it decreases morbidity in these patients by preventing radical axillary dissection, a previously standard approach, without compromising the diagnosis and hence, the prognosis of the patients. We demonstrated that with the correct technique for sentinel lymph node biopsy, the prognosis for patients is much better than for those patients that undergo radical axillary dissection.

Quantum Chemical Investigation of 1-Aminohomopiperidine in Treatment of Breast Cancer Based on Molecular Docking Strategy

The density functional theory DFT-B3LYP strategy is promising technique for investigating the molecular structure, wavenumber assignments and several structural properties. The compounds with piperidine ring were valuable substrates in the development of drugs. Therefore, this work was carried out for 1-aminohomopiperidine (1AHP) with B3LYP/6-311++G(d,p) calculations. Broad frequency analyses, molecular stability interactions and charge exchanges of the molecule have been detailed by natural bond orbital (NBO) analysis. Frontier molecular orbital analysis and the UV absorption have been studied by using DFT method. Furthermore, the molecular docking results exposed that the title molecule has a good binding affinity to the active sites interaction with ERα (estrogen receptor alpha) and used as a potential agent of breast cancer efficacy.

Reduction of breast tumor drug resistance by 2,3,5,4'-tetrahydroxystilbene for exhibition synergic chemotherapeutic effect.

Chemotherapy drugs have limited efficacy in breast cancer due to multidrug resistance generated by cancer cells against anticancer drugs. In this study, we developed a novel derivative, 2, 3, 5, 4‘-tetrahydroxystilbene (TG1) by modifying 2, 3, 5, 4‘-tetrahydroxystilbene-2-O-beta-D-glucoside (THSG). In-vivo zebrafish embryo tests revealed that TG1 showed low toxicity. The equitoxic combination of DOX or DTX with TG1 in MCF-7/Adr reduced the IC50 of DOX or DTX, and the combination index (CI) showed strong synergistic effects in the 1:3 molar ratio of DTX: TG1 and 1:5 molar ratio of DOX: TG1. Moreover, fluorescence images confirmed the cellular uptake of DOX when combined with TG1 in MCF-7/Adr. Western blotting analysis indicated downregulation of p-glycoprotein (P-gp) after MCF-7/Adr treated with TG1. In conclusion, the combined therapy of DTX or DOX and TG1 increases drug efficacy via suppressing the p-glycoprotein efflux pump. These results suggest that TG1 may have potential use for breast cancer patients, especially those with multidrug resistance.

Cancer du sein HER2-low : comment un concept biologique s’immisce-t-il dans la décision thérapeutique ?: HER2-low breast cancer: how does a biological concept interfere in therapeutic decision?

The emergence of a new tumor entity called HER2-low breast cancer leads us to reconsider therapeutic indications in patients whose tumors were usually considered as luminal or triple negative. The development of antibody-drug conjugates (ADCs) allows using HER2 as a vector of a cytoxic drug with significant clinical efficacy in breast cancer with low HER2 expression. Trastuzumab deruxtecan monotherapy is currently evaluated in phase III trials in HER2-low patients, but also in combination in earlier phase studies. Many ADCs are in development, with highly anticipated results. The toxicities of these various ADCs seem manageable and compatible with prolonged administration. Her2-low breast cancer subtype may benefit from dedicated therapeutic strategies in the next few years.

Nomogram to Predict Tumor-Infiltrating Lymphocytes in Breast Cancer Patients.

Background: Tumor-infiltrating lymphocytes (TILs) play important roles in the prediction of prognosis and neoadjuvant therapy (NAT) efficacy in breast cancer (BRCA) patients, in this study, we identified clinicopathological factors related to BRCA TILs, then to construct and validate nomogram to predict high density of TILs. Methods: A total of 826 patients diagnosed with BRCA in Sun Yat-Sen University cancer center were enrolled in nomogram cohort. TILs were assessed using hematoxylin-eosin (H&E) staining by two pathologists. Complete clinical data were collected for analysis. Then the enrolled patients were split into a training set and validation set at a ratio of 8:2. and the backward multivariate binary logistic regression model was used to establish nomogram for predicting BRCA TILs, which were further evaluated and validated using the C-index, receiver operating characteristic (ROC) curves and calibration curves. Then another independent NAT cohort of 106 patients was established for verifying this nomogram in NAT efficacy prediction. Results: TILs were significantly correlated with body mass index (BMI), tumor differentiation, ER, PR, HER2 expression, Ki67, blood biochemical indicators including total bilirubin (TBIL), indirect bilirubin (IBIL), total protein (TP), Globulin (GLOB), inorganic phosphorus (IP), calcium (Ca). In which ER expression level [OR = 0.987, 95%CI (0.982–0.992), p < 0.001], IP [OR = 4.462, 95%CI (1.171∼17.289), p = 0.029], IBIL [OR = 0.906, 95%CI (0.845–0.966), p = 0.004] and TP [OR = 1.053, 95%CI (1.010–1.098, p = 0.016)] were independent predictors of TILs. Then nomogram was established, for which calibration curves (C-index = 0.759) and ROC curve (AUC = 0.759, 95%CI 0.717–0.801) in training sets, calibration curves (C-index = 0.708) and ROC curve (AUC = 0.708, 95%CI 0.617–0.800) in validation sets demonstrated great evaluation efficiency. Besides, independent NAT cohort verified this nomogram can distinguish patients with greater NAT efficacy (p = 0.041). Conclusion: The finds of clinicopathological factors associated with TILs could help clinicians to understand the tumor immunity of BRCA and improve treatment system for patients, and the established nomogram with high evaluation efficiency may be used as a complement tool for distinguishing patients with better NAT efficacy.

Multimodal liquid biopsy for early monitoring and outcome prediction of chemotherapy in metastatic breast cancer

Circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) are two cancer-derived blood biomarkers that inform on patient prognosis and treatment efficacy in breast cancer. We prospectively evaluated the clinical validity of quantifying both CTCs (CellSearch) and ctDNA (targeted next-generation sequencing). Their combined value as prognostic and early monitoring markers was assessed in 198 HER2-negative metastatic breast cancer patients. All patients were included in the prospective multicenter UCBG study COMET (NCT01745757) and treated by first-line chemotherapy with weekly paclitaxel and bevacizumab. Blood samples were obtained at baseline and before the second cycle of chemotherapy. At baseline, CTCs and ctDNA were respectively detected in 72 and 74% of patients and were moderately correlated (Kendall’s τ = 0.3). Only 26 (13%) patients had neither detectable ctDNA nor CTCs. Variants were most frequently observed in TP53 and PIK3CA genes. KMT2C/MLL3 variants detected in ctDNA were significantly associated with a lower CTC count, while the opposite trend was seen with GATA3 alterations. Both CTC and ctDNA levels at baseline and after four weeks of treatment were correlated with survival. For progression-free and overall survival, the best multivariate prognostic model included tumor subtype (triple negative vs other), grade (grade 3 vs other), ctDNA variant allele frequency (VAF) at baseline (per 10% increase), and CTC count at four weeks (≥5CTC/7.5 mL). Overall, this study demonstrates that CTCs and ctDNA have nonoverlapping detection profiles and complementary prognostic values in metastatic breast cancer patients. A comprehensive liquid-biopsy approach may involve simultaneous detection of ctDNA and CTCs.

High-Throughput In Vitro Gene Expression Profile to Screen of Natural Herbals for Breast Cancer Treatment.

Breast cancer has surpassed lung cancer as the most commonly diagnosed cancer in women worldwide. Some therapeutic drugs and approaches could cause side effects and weaken the immune system. The combination of conventional therapies and traditional Chinese medicine (TCM) significantly improves treatment efficacy in breast cancer. However, the chemical composition and underlying anti-tumor mechanisms of TCM still need to be investigated. The primary aim of this study is to provide unique insights to screen the natural components for breast cancer therapy using high-throughput transcriptome analysis. Differentially expressed genes were identified based on two conditions: single samples and groups were classified according to their pharmaceutical effect. Subsequently, the sample treated with E. cochinchinensis Lour. generated the most significant DEGs set, including 1,459 DEGs, 805 upregulated and 654 downregulated. Similarly, group 3 treatment contained the most DEGs (414 DEGs, 311 upregulated and 103 downregulated). KEGG pathway analyses showed five significant pathways associated with the inflammatory and metastasis processes in cancer, which include the TNF, IL−17, NF-kappa B, MAPK signaling pathways, and transcriptional misregulation in cancer. Samples were classified into 13 groups based on their pharmaceutical effects. The results of the KEGG pathway analyses remained consistent with signal samples; group 3 presents a high significance. A total of 21 genes were significantly regulated in these five pathways, interestingly, IL6, TNFAIP3, and BRIC3 were enriched on at least two pathways, seven genes (FOSL1, S100A9, CXCL12, ID2, PRS6KA3, AREG, and DUSP6) have been reported as the target biomarkers and even the diagnostic tools in cancer therapy. In addition, weighted correlation network analysis (WGCNA) was used to identify 18 modules. Among them, blue and thistle2 were the most relevant modules. A total of 26 hub genes in blue and thistle2 modules were identified as the hub genes. In conclusion, we screened out three new TCM (R. communis L., E. cochinchinensis Lour., and B. fruticosa) that have the potential to develop natural drugs for breast cancer therapy, and obtained the therapeutic targets.

BSCI-14. tGLI1 is an actionable therapeutic target in breast cancer brain metastases

Breast cancer is the second leading cause of brain metastases in women; patients with breast cancer brain metastasis (BCBM) survive a median of 14.1 months following diagnosis. Cancer stem cells are thought to be one of the driving forces behind distant metastasis, treatment resistance, and late-stage recurrence. Despite advances made in understanding breast cancer stem cells (BCSC), it remains challenging to effectively target BCSC underscoring the need to identify and inhibit novel mediators of BCSC for treating BCBM patients. The hedgehog-smoothened pathway is an important mediator of breast cancer stem cells (BCSC); however, FDA-approved therapies targeting smoothened have demonstrated limited clinical efficacy in breast cancer. Truncated glioma-associated oncogene homolog 1 (tGLI1) was discovered in our laboratory as an alternative GLI1 splice variant that functions as a tumor-specific gain-of-function transcription factor and terminal effector of the hedgehog pathway. Our laboratory recently reported that tGLI1 promotes preferential metastasis to the brain in breast cancer by activating BCSC and astrocytes in the tumor microenvironment (Oncogene 39:64–78, 2020). tGLI1 knockdown abrogated BCBM, providing the rationale to therapeutically target tGLI1. This study aimed to determine if tGLI1 can be therapeutically targeted. Cell-based chemical screens followed by validations demonstrated that ketoconazole, an FDA-approved azole antifungal, and novel derivatives specifically inhibit tGLI1 leading to suppression of BCSC in vitro and BCBM in vivo. Mechanistic studies suggest that KCZ-dependent cell kill is, in part, mediated through downregulation of tGLI1 target genes OCT4, Nanog, and VEGFA. Based on these data, we opened a window-of-opportunity study in patients with BCBM to determine if ketoconazole penetrates the blood-brain barrier (BBB) and alters tGLI1 signaling in humans (NCT03796273). Preliminary sample analysis demonstrates ketoconazole crosses the blood-tumor barrier and that tGLI1 expression correlates with tGLI1 signaling in resected samples. Collectively, these data establish tGLI1 as an actionable target for BCBM.

M6A RNA Methylation Regulator YTHDF1 Correlated With Immune Microenvironment Predicts Clinical Outcomes and Therapeutic Efficacy in Breast Cancer.

Objective: Increasing evidence highlights the roles of N6-methyladenosine (m6A) and its regulators in oncogenesis. Herein, this study observed the associations of m6A regulators with breast cancer.Methods: RNA-seq profiles of breast cancer were retrieved from the Cancer Genome Atlas (TCGA) database. The expression of m6A regulators was analyzed in tumor and normal tissues. Their expression correlations were analyzed by Spearson test. Overall survival (OS) analysis of these regulators was then presented. Gene set enrichment analysis (GSEA) was performed in high and low YTHDF1 expression groups. The correlations of YTHDF1 expression with immune cells and tumor mutation burden (TMB) were calculated in breast cancer samples. Somatic variation was assessed in high and low YTHDF1 expression groups.Results: Most of m6A regulators were abnormally expressed in breast cancer compared to normal tissues. At the mRNA levels, there were closely relationships between them. Among them, YTHDF1 up-regulation was significantly related to undesirable prognosis (p = 0.025). GSEA results showed that high YTHDF1 expression was associated with cancer-related pathways. Furthermore, YTHDF1 expression was significantly correlated with T cells CD4 memory activated, NK cells activated, monocytes, and macrophages. There were higher TMB scores in YTHDF1 up-regulation group than its down-regulation group. Missense mutation and non-sense mutation were the most frequent mutation types.Conclusion: Our findings suggested that dysregulated m6A regulator YTHDF1 was predictive of survival outcomes as well as response to immunotherapy of breast cancer, and were closely related to immune microenvironment.

STAT1 potentiates oxidative stress revealing a targetable vulnerability that increases phenformin efficacy in breast cancer

Bioenergetic perturbations driving neoplastic growth increase the production of reactive oxygen species (ROS), requiring a compensatory increase in ROS scavengers to limit oxidative stress. Intervention strategies that simultaneously induce energetic and oxidative stress therefore have therapeutic potential. Phenformin is a mitochondrial complex I inhibitor that induces bioenergetic stress. We now demonstrate that inflammatory mediators, including IFNγ and polyIC, potentiate the cytotoxicity of phenformin by inducing a parallel increase in oxidative stress through STAT1-dependent mechanisms. Indeed, STAT1 signaling downregulates NQO1, a key ROS scavenger, in many breast cancer models. Moreover, genetic ablation or pharmacological inhibition of NQO1 using β-lapachone (an NQO1 bioactivatable drug) increases oxidative stress to selectively sensitize breast cancer models, including patient derived xenografts of HER2+ and triple negative disease, to the tumoricidal effects of phenformin. We provide evidence that therapies targeting ROS scavengers increase the anti-neoplastic efficacy of mitochondrial complex I inhibitors in breast cancer.

A nomogram to predict the value of mammary adipose index (MAI) for prediction of response to neoadjuvant chemotherapy in breast cancer patients.

e12607 Background: Breast cancer (BCa) is the most common malignancy in females on a global scale. Neoadjuvant chemotherapy (NACT) is a promising therapeutic approach for the treatment of locally advanced BCa, which result in primary tumor regression and optimal surgical planning. Cumulative evidence has identified a deleterious crosstalk between cancer cells and the surrounding mammary adipose tissue during tumor progression. Mammary adipose index (MAI) is a novel indicator defined by us, which represents the percentage of adipose tissue in breast. Therefore, this study aims to investigate the correlation between MAI and NACT efficacy of BCa by establishing an intuitive nomogram. Methods: Clinical data of 221 BCa patients who received NACT at the First Affiliated Hospital of Nanjing Medical University from January 1, 2018 to May 31, 2020 were retrospectively collected. Besides, patients were divided into major histological response and non-major histological response group in line with Miller-Payne pathology grading. The level of MAI was collected from magnetic resonance imaging of breast, and was divided into two groups according to the cut-off value. The level of MAI and clinicopathological characteristics were collected to assess the predictive roles of NACT response. Univariate analysis was performed by Chi-square test or Fisher’s exact test. Indicators with P &lt; 0.05 were included in multivariate binary logistic regression analysis. The nomogram was constructed based on results of multivariate logistic analysis. The predictive accuracy and discriminative ability were evaluated by C-index and the calibration curve. Results: Among the 221 patients enrolled, 77 cases (34.84%) were represented by major responses of pathologic histology. In univariate analysis, the level of MAI, tumor size, node status, ER status, PR status HER-2 status and Ki-67 status were correlated with NACT. Multivariate Logistic regression analysis showed that tumor size, HER-2 status and the level of MAI were independent influencing factors for the response to NACT in BCa patients. The patients with a high level of MAI (≥0.6916) were more likely to have a worse NACT response. MAI was an independent predictor for NACT efficacy, and area under the curve of ROC, specificity and sensitivity of the predictive model were 0.805, 0.632 and 0.774 respectively. The nomogram established based on these factors showed its discriminatory ability, and the C-index for prediction was 0.881. The calibration curve indicated that the predictive ability of the nomogram was a good fit to actual observation. The difference was statistically significant (P &lt; 0.05). Conclusions: The nomogram constructed in the present study indicated that the level of MAI could predict the efficacy of NACT in BCa patients, which might provide clinical guidance for the selection of appropriate treatment decisions.

16P Understanding the biologic determinants of ribociclib efficacy in breast cancer

Ribociclib improves survival in hormone receptor-positive (HR+)/HER2-negative (HER2-) advanced breast cancer (BC). Deeper understanding of the biology associated with ribociclib efficacy is needed, especially within the HER2-enriched (HER2-E) subtype given recent analysis of MONALEESA program. Here, we performed gene expression (GE) analysis with/without ribociclib monotherapy in BC patient-derived xenografts (PDX).

KIF15 expression characteristics: Relevance toneo-adjuvant chemotherapy efficacy in breast cancer*

Abstract Objective The relationship between the expression of kinesin family member 15 (KIF15) and clinicopathological features in breast cancer (BC) remains controversial. In this study, we aimed to explore the influence of KIF15 expression on the efficacy of neoadjuvant chemotherapy (NAC) and evaluate its clinical value in predicting prognosis for BC patients. Methods Immunohistochemistry was used to detect KIF15 expression in 93 BC patients undergoing NAC to analyze the relationship between KIF15 expression and clinical efficacy and analytical parameters. Results Of the 93 BC patients enrolled, 24.73% who underwent NAC had higher KIF15 expression levels, showing positive correlations with ER, HER-2, Ki67, and lymph node metastasis (P &lt; 0.05). The clinical benefit of NAC was 70.97%, and the major histological response (MHR) rate was 61.29%. The effective therapeutic rate in patients with high KIF15 expression was 95.65%, while the MHR rate was 65.22%. Various molecular BC subtypes with varied clinical and pathological responses exhibited correlation to a large extent. Of all the BC patients studied, 84% of the triple-negative breast cancer (TNBC) patients were evaluated as clinically effective, and 52% of the TNBC patients were evaluated as pathologically effective, and these values were significantly higher than those of the other molecular types (P &lt; 0.05). The expression of KIF15 in 25 TNBC patients showed positive correlations with lymph node metastasis. Conclusion Overexpression of KIF15 was shown to increase BC sensitivity to chemotherapy and demonstrated better outcomes.

Clinical Outcomes for Patients With Metastatic Breast Cancer Treated With Immunotherapy Agents in Phase I Clinical Trials.

BackgroundImmuno-oncology (IO) agents have demonstrated efficacy across many tumor types and have led to change in standard of care. In breast cancer, atezolizumab and pembrolizumab were recently FDA-approved in combination with chemotherapy specifically for patients with PD-L1-positive metastatic triple-negative breast cancer (TNBC). However, the single agent PD-1/PD-L1 inhibitors demonstrate only modest single agent efficacy in breast cancer. The purpose of this study was to investigate the efficacy of novel IO agents in patients with metastatic breast cancer (MBC), beyond TNBC, treated in phase I clinical trials at the University of Colorado.MethodsWe performed a retrospective analysis using a database of patients with MBC who received treatment with IO agents in phase I/Ib clinical trials at the University of Colorado Hospital from January 1, 2012 to July 1, 2018. Patient demographics, treatments and clinical outcomes were obtained.ResultsWe identified 43 patients treated with an IO agent either as a single agent or in combination. The average age was 53 years; 55.8% had hormone receptor-positive/HER2-negative breast cancer, 39.5% TNBC and 4.7% HER2-positive. Patients received an average of 2 prior lines of chemotherapy (range 0-7) in the metastatic setting. Most patients (72.1%) received IO alone and 27.9% received IO plus chemotherapy. Median progression-free survival (PFS) was 2.3 months and median overall survival (OS) was 12.1 months. Patients remaining on study ≥ 6 months (20.9%) were more likely to be treated with chemotherapy plus IO compared to patients with a PFS < 6 months (77.8% v. 14.7%). No differences in number of metastatic sites, prior lines of chemotherapy, breast cancer subtype, absolute lymphocyte count, or LDH were identified between patients with a PFS ≥ 6 months vs. < 6 months.ConclusionsOur phase I experience demonstrates benefit from IO therapy that was not limited to patients with TNBC and confirms improved efficacy from IO agents in combination with chemotherapy. A subset of patients with MBC treated in phase I clinical trials with an IO agent derived prolonged clinical benefit. Predictors of response to immunotherapy in breast cancer remain uncharacterized and further research is needed to identify these factors.

Abstract PS17-14: Evaluating the efficacy of immunotherapy in triple negative breast cancer

Abstract The breast cancer microenvironment comprises a complex stroma including tumor-infiltrating lymphocytes (TILs), which can either stimulate tumor progression or promote anti-tumor immunity in response to tumor-derived cues. In general, of all clinical subtypes, triple-negative breast cancer (TNBC) is characterized by the most extensive infiltration of TILs within tumor stroma, which is consistent with the observation that TNBC seems to clinically respond to immunotherapies at the highest rates. Immune checkpoint blockade (ICB), an immunotherapy that promotes prolonged activation of cytotoxic immune cells to mount robust anti-tumorigenic responses, has yielded limited success in treating breast cancer. IMpassion130 was the first clinical trial to indicate that combining anti-PD-L1 with standard-of-care chemotherapy (nab-paclitaxel) to treat TNBC increases progression-free survival in patients exclusively those with PD-L1 positive tumors. Furthermore, the KEYSTONE-522 trial showed that administering anti-PD-1 in addition to various neoadjuvant chemotherapies increased the pathologic complete response in early stage TNBC patients. Despite promising evidence for immunotherapy success, both clinical trials lacked an experimental ICB-only group, and thus cannot address the therapeutic benefit of ICB alone, or which chemotherapy combination would maximize this benefit. Finally, mechanisms of resistance to ICB in breast cancer remain unexplored. We sought to model ICB response in vivo to elucidate the mechanisms responsible for immunotherapy efficacy in breast cancer, explore the synergistic effects of ICB with chemotherapies, and model ICB resistance.In this study, we investigated the efficacy of anti-PD-L1 as single-agent or in combination with paclitaxel or doxorubicin in the EMT6 (Balb/c) orthotopic mammary tumor model. In this model, single-agent immunotherapy was efficacious in reducing primary tumor growth compared to combination treatment, with a small proportion of complete responses, whereas modest benefit was observed with either chemotherapy alone. Following two rounds of treatment, we analyzed the tumor-immune microenvironment by flow cytometry and gene expression analysis. Anti-PD-L1 alone or in combination with either chemotherapy enhanced infiltration of cytotoxic and effector T cell as well as natural killer cells into the tumor microenvironment. Using gene expression analysis, we observed elevated expression of myeloid recruitment and activation markers in combination-treated tumors, supporting a known role of chemotherapy-induced cell death in myeloid recruitment; however as chemotherapy did not add benefit to tumor response or survival, it is unclear if this effect is detrimental or supportive. Interestingly, completely responsive anti-PD-L1 treated tumors that eventually recurred retained resistance to ICB upon re-implantation in naïve recipient mice, suggesting that tumor-intrinsic factors may contribute to resistance.Herein, we explore an in vivo model that corroborates clinical response to combinatorial immunotherapy approaches in breast cancer patients. We report the immunogenic efficacy of single-agent ICB that upregulates tumoricidal immune cell infiltration into the primary tumor, thereby controlling tumor growth, albeit without achieving complete response in all mice. Additionally, post-therapy recurrent tumors retain resistance upon transplantation, indicating tumor-specific adaptive resistance. This study has potentially significant clinical implications for re-evaluating the contributions of chemotherapy in combination with ICB in TNBC patients. Citation Format: Ann Hanna, Paula I. Gonzalez-Ericsson, Violeta Sanchez, Melinda E. Sanders, Justin M. Balko. Evaluating the efficacy of immunotherapy in triple negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS17-14.

Is there a correlation between miR-301a expression and neoadjuvant chemotherapy efficacy in breast cancer tissue?

Neoadjuvant chemotherapy (NAC) is the standard therapeutic regimen for locally advanced breast cancer. However, clinical physical examination and imaging results fail to accurately assess the treatment response, and postoperative pathological examination has a time lag in response to therapeutic effect which is not conducive to the timely adjustment of treatment strategies. A previous study has shown that miR-301a was associated with invasion and metastasis in breast cancer, and was found to be involved in endocrine therapy resistance; however, evidence regarding the correlation between miR-301a expression and NAC efficacy remains scarce. In this study, 101 patients with locally advanced breast cancer were included. All patients received anthracycline based chemotherapy. The expression level of miR-301a in pretreatment core needle biopsy tissues was determined by real-time polymerase chain reaction analysis. Relevant clinicopathological data were collected, and the correlation between miR-301a expression and NAC efficacy was assessed. Based on our data, miR-301a cannot be used to identify whether breast cancer benefits from NAC, and no correlation was observed between miR-301a expression and clinicopathological characteristics. In conclusion, miR-301a may not be a potential prognostic biomarker of NAC efficacy in breast cancer.

Nomogram-derived prediction of pathologic complete response (pCR) in breast cancer patients treated with neoadjuvant chemotherapy (NCT)

BackgroundPrevious research results on the predictive factors of neoadjuvant chemotherapy (NCT) efficacy in breast cancer are inconsistent, suggesting that the ability of a single factor to predict efficacy is insufficient. Combining multiple potential efficacy-related factors to build a model may improve the accuracy of prediction. This study intends to explore the clinical and biological factors in breast cancer patients receiving NCT and to establish a nomogram that can predict the pathologic complete response (pCR) rate of NCT.MethodsWe selected 165 breast cancer patients receiving NCT from July 2017 to May 2019. Using pretreatment biopsy materials, immunohistochemical studies to assess estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), and Ki-67 expression. The correlation between biological markers and pCR was analyzed. These predictors were used to develop a binary logistic regression model with cross-validation and to show the established predictive model with a nomogram.ResultsThe nomogram for pCR based on lymphovascular invasion, anemia (hemoglobin≤120 g/L), ER, Ki67 expression levels and NCT regimen had good discrimination performance (area under the curve [AUC], 0.758; 95% confidence interval [CI], 0.675–0.841) and calibration coordination. According to the Hosmer-Lemeshow test, the calibration chart showed satisfactory agreement between the predicted and observed probabilities. The final prediction accuracy of cross-validation was 76%.ConclusionsWe developed a nomogram based on multiple clinical and biological covariations that can provide an early prediction of NCT response and can help to quickly assess the individual benefits of NCT.

RNA-seq reveals novel cancer-selective and disease subtype-independent mechanistic targets of withaferin A in human breast cancer cells.

Withaferin A (WA) exhibits cancer chemopreventive efficacy in preclinical models representative of two different subtypes of breast cancer. However, the mechanism(s) underlying breast cancer chemoprevention by WA is not fully elucidated. We performed RNA-seq analyses using a non-tumorigenic mammary epithelial cell line (MCF-10A) and human breast cancer cells (BCC) belonging to the luminal-type (MCF-7), HER2-enriched (SK-BR-3), and basal-like subtype (MDA-MB-231) to identify novel cancer-selective mechanistic targets of WA. The WA-regulated transcriptome was strikingly different between MCF-10A versus BCC. The Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed downregulation of genes associated with cellular senescence in WA-treated BCC. Consequently, the number of senescence-associated β-galactosidase positive cells was decreased significantly in WA-treated BCC but not in the MCF-10A cells. WA treatment caused upregulation of senescence marker p21 more robustly in BCC than in MCF-10A. Breast cancer prevention by WA in rats was also associated with upregulation of p21 protein expression. The Reactome pathway analyses indicated upregulation of genes associated with cellular response to stress/external stimuli in WA-treated BCC but not in MCF-10A. Two proteins represented in these pathways (HSPA6 and NRF2) were further investigated. While HSPA6 was dispensable for WA-mediated apoptosis and autophagy or inhibition of cell migration, the NRF2 knockout cells were more resistant to apoptosis resulting from WA treatment than control cells. Finally, expression of some glycolysis-related proteins was decreased by WA treatment both in vitro and in vivo. In summary, this study provides novel insights into cancer-selective pathways affected by WA that may contribute to its chemopreventive efficacy in breast cancer.