A spatially resolved single-cell genomic atlas of the adult human breast.

The adult human breast is comprised of an intricate network of epithelial ducts and lobules that are embedded in connective and adipose tissue1-3. Although most previous studies have focused on the breast epithelial system4-6, many of the non-epithelial cell types remain understudied. Here we constructed the comprehensive Human Breast Cell Atlas (HBCA) at single-cell and spatial resolution. Our single-cell transcriptomics study profiled 714,331 cells from 126 women, and 117,346 nuclei from 20 women, identifying 12 major cell types and 58 biological cell states. These data reveal abundant perivascular, endothelial and immune cell populations, and highly diverse luminal epithelial cell states. Spatial mapping using four different technologies revealed an unexpectedly rich ecosystem of tissue-resident immune cells, as well as distinct molecular differences between ductal and lobular regions. Collectively, these data provide a reference of the adult normal breast tissue for studying mammary biology and diseases such as breast cancer.

The breast tissue microbiome, stroma, immune cells and breast cancer.

BACKGROUND: Stromal and immune cell composition alterations in benign breast tissue associate with future cancer risk. Pilot data suggest the innate microbiome of normal breast tissue differs between women with and without breast cancer. Microbiome alterations might explain tissue microenvironment variations associated with disease status. METHODS: Prospectively-collected sterile normal breast tissues from women with benign (n=16) or malignant (n=17) disease underwent 16SrRNA sequencing with Illumina MiSeq and Hybrid-denovo pipeline processing. Breast tissue was scored for fibrosis and fat percentages and immune cell infiltrates (lobulitis) classified as absent/mild/moderate/severe. Alpha and beta diversity were calculated on rarefied OTU data and associations analyzed with multiple linear regression and PERMANOVA. RESULTS: Breast tissue stromal fat% was lower and fibrosis% higher in benign disease versus cancer (median 30% versus 60%, p=0.01, 70% versus 30%, p=0.002, respectively). The microbiome varied with stromal composition. Alpha diversity (Chao1) correlated with fat% (r=0.38, p=0.02) and fibrosis% (r=-0.32, p=0.05) and associated with different microbial populations as indicated by beta diversity metrics (weighted UniFrac, p=0.08, fat%, p=0.07, fibrosis%). Permutation testing with FDR control revealed taxa differences for fat% in Firmicutes, Bacilli, Bacillales, Staphylococcaceae and genus Staphylococcus, and fibrosis% in Firmicutes, Spirochaetes, Bacilli, Bacillales, Spirochaetales, Proteobacteria RF32, Sphingomonadales, Staphylococcaceae, and genera Clostridium, Staphylococcus, Spirochaetes, Actinobacteria Adlercreutzia. Moderate/severe lobulitis was more common in cancer (73%) than benign disease (13%), p=0.003, but no significant microbial associations were seen. CONCLUSION: These data suggest a link between breast tissue stromal alterations and its microbiome, further supporting a connection between the breast tissue microenvironment and breast cancer.

Tissue-resident FOLR2+ macrophages associate with CD8+ T cell infiltration in human breast cancer.

Macrophage infiltration is a hallmark of solid cancers, and overall macrophage infiltration correlates with lower patient survival and resistance to therapy. Tumor-associated macrophages, however, are phenotypically and functionally heterogeneous. Specific subsets of tumor-associated macrophage might be endowed with distinct roles on cancer progression and antitumor immunity. Here, we identify a discrete population of FOLR2+ tissue-resident macrophages in healthy mammary gland and breast cancer primary tumors. FOLR2+ macrophages localize in perivascular areas in the tumor stroma, where they interact with CD8+ T cells. FOLR2+ macrophages efficiently prime effector CD8+ T cells ex vivo. The density of FOLR2+ macrophages in tumors positively correlates with better patient survival. This study highlights specific roles for tumor-associated macrophage subsets and paves the way for subset-targeted therapeutic interventions in macrophages-based cancer therapies.

The Leptin Axis and Its Association With the Adaptive Immune System in Breast Cancer.

Adipose tissue secretes various peptides, including leptin. This hormone acts through the leptin receptor (Ob-R), which is expressed ubiquitously on the surface of various cells, including breast cancer cells and immune cells. Increasing evidence points to an interaction between the tumor microenvironment, tumor cells, and the immune system. Leptin plays an important role in breast cancer tumorigenesis and may be implicated in activation of the immune system. While breast cancer cannot be considered an immunogenic cancer, the triple-negative subtype is an exception. Specific immune cells - tumor infiltrating lymphocytes - are involved in the immune response and act as predictive and prognostic factors in certain breast cancer subtypes. The aim of this article is to review the interaction between adipose tissue, through the expression of leptin and its receptor, and the adaptive immune system in breast cancer.

Spatial immunophenotypes predict response to anti-PD1 treatment and capture distinct paths of T cell evasion in triple negative breast cancer.

Only a subgroup of triple-negative breast cancer (TNBC) responds to immune checkpoint inhibitors (ICI). To better understand lack of response to ICI, we analyze 681 TNBCs for spatial immune cell contextures in relation to clinical outcomes and pathways of T cell evasion. Excluded, ignored and inflamed phenotypes can be captured by a gene classifier that predicts prognosis of various cancers as well as anti-PD1 response of metastatic TNBC patients in a phase II trial. The excluded phenotype, which is associated with resistance to anti-PD1, demonstrates deposits of collagen-10, enhanced glycolysis, and activation of TGFß/VEGF pathways; the ignored phenotype, also associated with resistance to anti-PD1, shows either high density of CD163+ myeloid cells or activation of WNT/PPARγ pathways; whereas the inflamed phenotype, which is associated with response to anti-PD1, revealed necrosis, high density of CLEC9A+ dendritic cells, high TCR clonality independent of neo-antigens, and enhanced expression of T cell co-inhibitory receptors.

Changes in Immune Cell Types with Age in Breast are Consistent with a Decline in Immune Surveillance and Increased Immunosuppression.

A majority of breast cancers (BC) are age-related and we seek to determine what cellular and molecular changes occur in breast tissue with age that make women more susceptible to cancer initiation. Immune-epithelial cell interactions are important during mammary gland development and the immune system plays an important role in BC progression. The composition of human immune cell populations is known to change in peripheral blood with age and in breast tissue during BC progression. Less is known about changes in immune populations in normal breast tissue and how their interactions with mammary epithelia change with age. We quantified densities of T cells, B cells, and macrophage subsets in pathologically normal breast tissue from 122 different women who ranged in age from 24 to 74 years old. Donor-matched peripheral blood from a subset of 20 donors was analyzed by flow cytometry. Tissue immune cell densities and localizations relative to the epithelium were quantified in situ with machine learning-based image analyses of multiplex immunohistochemistry-stained tissue sections. In situ results were corroborated with flow cytometry analyses of peri-epithelial immune cells from primary breast tissue preparations and transcriptome analyses of public data from bulk tissue reduction mammoplasties. Proportions of immune cell subsets in breast tissue and donor-matched peripheral blood were not correlated. Density (cells/mm2) of T and B lymphocytes in situ decreased with age. T cells and macrophages preferentially localized near or within epithelial bilayers, rather than the intralobular stroma. M2 macrophage density was higher than M1 macrophage density and this difference was due to higher density of M2 in the intralobular stroma. Transcriptional signature analyses suggested age-dependent decline in adaptive immune cell populations and functions and increased innate immune cell activity. T cells and macrophages are so intimately associated with the epithelia that they are embedded within the bilayer, suggesting an important role for immune-epithelial cell interactions. Age-associated decreased T cell density in peri-epithelial regions, and increased M2 macrophage density in intralobular stroma suggests the emergence of a tissue microenvironment that is simultaneously immune-senescent and immunosuppressive with age.

Single-cell evaluation reveals shifts in the tumor-immune niches that shape and maintain aggressive lesions in the breast.

There is an unmet clinical need for stratification of breast lesions as indolent or aggressive to tailor treatment. Here, single-cell transcriptomics and multiparametric imaging applied to a mouse model of breast cancer reveals that the aggressive tumor niche is characterized by an expanded basal-like population, specialization of tumor subpopulations, and mixed-lineage tumor cells potentially serving as a transition state between luminal and basal phenotypes. Despite vast tumor cell-intrinsic differences, aggressive and indolent tumor cells are functionally indistinguishable once isolated from their local niche, suggesting a role for non-tumor collaborators in determining aggressiveness. Aggressive lesions harbor fewer total but more suppressed-like T cells, and elevated tumor-promoting neutrophils and IL-17 signaling, disruption of which increase tumor latency and reduce the number of aggressive lesions. Our study provides insight into tumor-immune features distinguishing indolent from aggressive lesions, identifies heterogeneous populations comprising these lesions, and supports a role for IL-17 signaling in aggressive progression.

Predicting the immune landscape of invasive breast carcinoma based on the novel signature of immune-related lncRNA.

BACKGROUND: The composition of the population of immune-related long non-coding ribonucleic acid (irlncRNA) generates a signature, irrespective of expression level, with potential value in predicting the survival status of patients with invasive breast carcinoma. METHODS: The current study uses univariate analysis to identify differentially expressed irlncRNA (DEirlncRNA) pairs from RNA-Seq data from The Cancer Genome Atlas (TCGA). 36 pairs of DEirlncRNA pairs were identified. Using various algorithms to construct a model, we have compared the area under the curve and calculated the 5-year curve of Akaike information criterion (AIC) values, which allows determination of the threshold indicating the maximum value for differentiation. Through cut-off point to establish the optimal model for distinguishing high-risk or low-risk groups among breast cancer patients. We assigned individual patients with invasive breast cancer to either high risk or low risk groups depending on the cut-off point, re-evaluated the tumor immune cell infiltration, the effectiveness of chemotherapy, immunosuppressive biomarkers, and immunotherapy. RESULTS: After re-assessing patients according to the threshold, we demonstrated an effective means of distinguish the severity of the disease, and identified patients with different clinicopathological characteristics, specific tumor immune infiltration states, high sensitivity to chemotherapy,wellpredicted response to immunotherapy and thus a more favorable survival outcome. CONCLUSIONS: The current study presents novel findings regarding the use of irlncRNA without the need to predict precise expression levels in the prognosis of breast cancer patients and to indicate their suitability for anti-tumor immunotherapy.

Inflammatory breast cancer appearance at presentation is associated with overall survival.

BACKGROUND: Inflammatory breast cancer (IBC) is a clinical diagnosis. Here, we examined the association of a "classic" triad of clinical signs, swollen involved breast, nipple change, and diffuse skin change, with overall survival (OS). METHOD: Breast medical photographs from patients enrolled on a prospective IBC registry were scored by two independent reviewers as classic (triad above), not classic, and difficult to assign. Chi-squared test, Fisher's exact test, and Wilcoxon rank-sum test were used to assess differences between patient groups. Kaplan-Meier estimates and the log-rank test and Cox proportional hazard regression were used to assess the OS. RESULTS: We analyzed 245 IBC patients with median age 54 (range 26-81), M0 versus M1 status (157 and 88 patients, respectively). The classic triad was significantly associated with smoking, post-menopausal status, and metastatic disease at presentation (p = 0.002, 0.013, and 0.035, respectively). Ten-year actuarial OS for not classic and difficult to assign were not significantly different and were grouped for further analyses. Ten-year OS was 29.7% among patients with the classic sign triad versus 57.2% for non-classic (p < 0.0001). The multivariate Cox regression model adjusting for clinical staging (p < 0.0001) and TNBC status (<0.0001) demonstrated classic presentation score significantly associated with poorer OS time (HR 2.6, 95% CI 1.7-3.9, p < 0.0001). CONCLUSIONS: A triad of classic IBC signs independently predicted OS in patients diagnosed with IBC. Further work is warranted to understand the biology related to clinical signs and further extend the understanding of physical examination findings in IBC.

Down-regulation of a panel of immune-related lncRNAs in breast cancer.

Breast cancer is a common neoplasm among women. This type of cancer is among malignancies in which role of long non-coding RNAs (lncRNAs) has been extensively explored. Some recently recognized lncRNAs have been less investigated in this neoplastic condition. LncRNAs that regulate tumor immunity are among those contributing in the pathogenesis of cancer. In the present expression assay, we compared expressions of nine immune-related lncRNAs namely lnc-MICAL3-2 (AC016027.1), lnc-DDX31 (AL445645.1), LINC01063, LINC02381, ENST0000615051 (AC083809.1), AC009237.14 (lnc-TRIM43B-1), ENST0000603791, LINC1234 and AC008760.1 between breast cancer samples and their paired non-cancerous samples. Expression levels of lnc-MICAL3-2, lnc-DDX31, LINC01063, LINC02381, ENST0000615051 and lnc-TRIM43B-1 were significantly decreased in breast cancer samples compared with paired control tissues (Posterior mean difference= -2.774, -2.012, -2.012, -2.015, -0.884 and -2.872; P values= 0.019, 0.0001, 0.0001, 0.0001, 0.032 and 0.0001, respectively). Expression levels of these lncRNAs have been associated with a number of clinical characteristics of breast cancer patients. Lnc-TRIM43B-1 had the highest performance in distinguishing between tumoral and non-tumoral tissues (AUC=0.82, Sensitivity=76%, Specificity=73.24%). As these lncRNAs could differentiate tumor samples from control samples, they might be regarded as putative tissue markers for breast cancer.

Immune checkpoint inhibitors for triple-negative breast cancer: From immunological mechanisms to clinical evidence.

Breast cancer is the most common cancer type in women worldwide. Triple-negative breast cancer (TNBC), which is characterized by the absence of estrogen receptor/progesterone receptor (ER/PR) and human epidermal growth factor receptor 2 (Her2) expressions, has a poorer prognosis compared with non-TNBC breast tumors. Until recently systemic treatment for TNBC was confined to chemotherapy owing to the lack of actionable targets. Immune checkpoint molecules are expressed on malignant cells or tumor-infiltrating immune cells and can inhibit anti-cancer immune responses. Immune checkpoint inhibitors (ICI), including anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), anti-programmed cell death protein 1 (PD-1), and anti-programmed cell death 1 ligand 1 (PD-L1), induce immune responses in different types of neoplasms. They have recently gained attention for their possible role in TNBC treatment. Several clinical trials have been conducted on the role of immune checkpoint blockade in different settings for TNBC treatment. Available evidence justifies the application of ICI and chemotherapy combination in the management of metastatic TNBC and early-stage TNBC in neoadjuvant setting. This study aims to provide information on the mechanisms of action of ICIs, review the efficacy results of clinical trials using ICIs for TNBC treatment, and assess the side effects of such drugs.

Breast cancer immunotherapy: Current and novel approaches.

The crucial role of the immune system in the progression/regression of breast cancer (BC) should always be taken into account. Various immunotherapy approaches have been investigated for BC, including tumor-targeting antibodies (bispecific antibodies), adoptive T cell therapy, vaccines, and immune checkpoint blockade such as anti-PD-1. In addition, a combination of conventional chemotherapy and immunotherapy approaches contributes to improving patients' overall survival rates. Although encouraging outcomes have been reported in most clinical trials of immunotherapy, some obstacles should still be resolved in this regard. Recently, personalized immunotherapy has been proposed as a potential complementary medicine with immunotherapy and chemotherapy for overcoming BC. Accordingly, this review discusses the brief association of these methods and future directions in BC immunotherapy.

Identification of the prognostic value of ferroptosis-related gene signature in breast cancer patients.

BACKGROUND: Breast cancer (BRCA) is a malignant tumor with high morbidity and mortality, which is a threat to women's health worldwide. Ferroptosis is closely related to the occurrence and development of breast cancer. Here, we aimed to establish a ferroptosis-related prognostic gene signature for predicting patients' survival. METHODS: Gene expression profile and corresponding clinical information of patients from The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database. The Least absolute shrinkage and selection operator (LASSO)-penalized Cox regression analysis model was utilized to construct a multigene signature. The Kaplan-Meier (K-M) and Receiver Operating Characteristic (ROC) curves were plotted to validate the predictive effect of the prognostic signature. Gene Ontology (GO) and Kyoto Encyclopedia of Genes, Genomes (KEGG) pathway and single-sample gene set enrichment analysis (ssGSEA) were performed for patients between the high-risk and low-risk groups divided by the median value of risk score. RESULTS: We constructed a prognostic signature consisted of nine ferroptosis-related genes (ALOX15, CISD1, CS, GCLC, GPX4, SLC7A11, EMC2, G6PD and ACSF2). The Kaplan-Meier curves validated the fine predictive accuracy of the prognostic signature (p < 0.001). The area under the curve (AUC) of the ROC curves manifested that the ferroptosis-related signature had moderate predictive power. GO and KEGG functional analysis revealed that immune-related responses were largely enriched, and immune cells, including activated dendritic cells (aDCs), dendritic cells (DCs), T-helper 1 (Th1), were higher in high-risk groups (p < 0.001). Oppositely, type I IFN response and type II IFN response were lower in high-risk groups (p < 0.001). CONCLUSION: Our study indicated that the ferroptosis-related prognostic signature gene could serve as a novel biomarker for predicting breast cancer patients' prognosis. Furthermore, we found that immunotherapy might play a vital role in therapeutic schedule based on the level and difference of immune-related cells and pathways in different risk groups for breast cancer patients.

T Cells Expressing Receptor Recombination/Revision Machinery Are Detected in the Tumor Microenvironment and Expanded in Genomically Over-unstable Models.

Tumors undergo dynamic immunoediting as part of a process that balances immunologic sensing of emerging neoantigens and evasion from immune responses. Tumor-infiltrating lymphocytes (TIL) comprise heterogeneous subsets of peripheral T cells characterized by diverse functional differentiation states and dependence on T-cell receptor (TCR) specificity gained through recombination events during their development. We hypothesized that within the tumor microenvironment (TME), an antigenic milieu and immunologic interface, tumor-infiltrating peripheral T cells could reexpress key elements of the TCR recombination machinery, namely, Rag1 and Rag2 recombinases and Tdt polymerase, as a potential mechanism involved in the revision of TCR specificity. Using two syngeneic invasive breast cancer transplantable models, 4T1 and TS/A, we observed that Rag1, Rag2, and Dntt in situ mRNA expression characterized rare tumor-infiltrating T cells. In situ expression of the transcripts was increased in coisogenic Mlh1-deficient tumors, characterized by genomic overinstability, and was also modulated by PD-1 immune-checkpoint blockade. Through immunolocalization and mRNA hybridization analyses, we detected the presence of rare TDT+RAG1/2+ cells populating primary tumors and draining lymph nodes in human invasive breast cancer. Analysis of harmonized single-cell RNA-sequencing data sets of human cancers identified a very small fraction of tumor-associated T cells, characterized by the expression of recombination/revision machinery transcripts, which on pseudotemporal ordering corresponded to differentiated effector T cells. We offer thought-provoking evidence of a TIL microniche marked by rare transcripts involved in TCR shaping.

NEFM DNA methylation correlates with immune infiltration and survival in breast cancer.

BACKGROUND: This study aims to determine whether NEFM (neurofilament medium) DNA methylation correlates with immune infiltration and prognosis in breast cancer (BRCA) and to explore NEFM-connected immune gene signature. METHODS: NEFM transcriptional expression was analyzed in BRCA and normal breast tissues using Oncomine and Tumor Immune Estimation Resource (TIMER) databases. The relationship between NEFM DNA methylation and NEFM transcriptional expression was investigated in TCGA. Potential influence of NEFM DNA methylation/expression on clinical outcome was evaluated using TCGA BRCA, The Human Protein Atlas and Kaplan-Meier plotter databases. Association of NEFM transcriptional expression/DNA methylation with cancer immune infiltration was investigated using TIMER and TISIDB databases. RESULTS: High expression of NEFM correlated with better overall survival (OS) and recurrence-free survival (RFS) in TCGA BRCA and Kaplan-Meier plotter, whereas NEFM DNA methylation with worse OS in TCGA BRCA. NEFM transcriptional expression negatively correlated with DNA methylation. NEFM DNA methylation significantly negatively correlated with infiltrating levels of B, CD8+ T/CD4+ T cells, macrophages, neutrophils and dendritic cells in TIMER and TISIDB. NEFM expression positively correlated with macrophage infiltration in TIMER and TISIDB. After adjusted with tumor purity, NEFM expression weekly negatively correlated with infiltration level of B cells, whereas positively correlated with CD8+ T cell infiltration in TIMER gene modules. NEFM expression/DNA methylation correlated with diverse immune markers in TCGA and TISIDB. CONCLUSIONS: NEFM low-expression/DNA methylation correlates with poor prognosis. NEFM expression positively correlates with macrophage infiltration. NEFM DNA methylation strongly negatively correlates with immune infiltration in BRCA. Our study highlights novel potential functions of NEFM expression/DNA methylation in regulation of tumor immune microenvironment.

Macrophage balance fraction determines the degree of immunosuppression and metastatic ability of breast cancer.

Macrophages are important immune cells in the tumor microenvironment and can be divided into two polarized subtypes, M1 and M2. M1 type macrophages have anti-tumor effects, while M2 type macrophages have pro-tumor effect. Most of the current researches are limited to the effect of M1 or M2 macrophages on tumors, while ignoring the overall balance of macrophages. Our research suggests that the macrophage balance fraction (MBF) can more effectively and comprehensively reflect the balance of tumor associated macrophages. Using bioinformatics analysis and in vitro experiments, we found that MBF is also an effective indicator of the degree of immunosuppression and metastatic ability of breast cancer, and different MBF environment can impact the migration and invasion ability of breast cancer cells. Finally, we also found that the mechanism of MBF changes in breast cancer may be affected by breast cancer-derived exosomes. In summary, MBF was proposed and validated as a novel indicator of macrophage balance state. Using this indicator, we found that the balance of macrophages can affect the degree of immunosuppression and metastatic ability of breast cancer.

Tumor-infiltrating B cells and T cells correlate with postoperative prognosis in triple-negative carcinoma of the breast.

BACKGROUND: In this study, we investigated CD20+ TILs in triple-negative breast cancer (TNBC) and their relationship with T lymphocyte subsets (CD4+, CD8+, CD25+, and FOXP3+), including their combined prognostic value using an immunohistochemical staining method. METHODS: We investigated 107 patients with TNBC for whom a full-face section stained by hematoxylin and eosin between 2006 and 2018 at Dokkyo Medical University Hospital was available. RESULTS: The strongest association of infiltrating CD20+ TILs was with CD4+ TILs. There was a significant relationship between CD20+ and CD4+ TILs (r = 0.177; p < 0.001), CD8+ TILs (r = 0.085; p = 0.002), and FOXP3+ TILs (r = 0.0043; p = 0.032). No significant relationships were observed between the CD20+ and CD25+ TILs (r = 0.012; p = 0.264). Multivariate analysis revealed that only the CD20+/FOXP3 ratio was an independent factor for relapse-free survival (p < 0.001) and overall survival (p < 0.001). Patients with tumors highly infiltrated by CD4+, CD8+, and CD20+ TILs had a good prognosis. In contrast, those with tumors weakly infiltrated by CD20+ TILs but highly infiltrated by CD25+ and FOXP3+ TILs had a poor prognosis. CONCLUSIONS: CD20+ TILs may support an increase in CD4+ and CD8+ TILs, which altered the anti-tumor response, resulting in a positive prognosis. CD20+ TILs correlated with FOXP3+ Treg lymphocytes, which were reported to be correlated with a poor prognosis. Our study suggested that TIL-B cells have dual and conflicting roles in TIL-T immune reactions in TNBC.

Comparison of tumor microenvironment in primary and paired metastatic ER+/HER2- breast cancers: results of a pilot study.

BACKGROUND: Tumor microenvironment (TME) is a dynamic setting and changes in TILs and their subpopulations are potential candidates to influence the metastatic process. Aim of this pilot study is to describe the changes occurring between primary breast cancers and their paired metastases in terms of TILs composition. To assess if these changes influence the process of metastasis development, we used a control group of patients. METHODS: We retrospectively identified 18 Luminal patients, for whom primary and metastatic tissue were available (cases) and 18 paired-matched patients (controls), not relapsed after at least 9 years of follow-up, and we quantified TILs and their composition (i.e. T CD8+ and CD4+/FOXP3+). The presence of TILs was defined as ≥10%. RESULTS: Our results showed that the microenvironment composition of relapsed patients was poor of TILs (median = 5%, I-III quartiles = 0.6-5%), CD8+ (2.5%, 0-5%) and CD4+/FOXP3 + (0%, 0-0.6%) in the primary tumor. Comparable results were observed in their related metastases (TILs 3.8%, 0.6-5%; CD8+ 0%, 0-1.3%; CD4+/FOXP3+ 0%,0-1.9%). On the contrary, the microenvironment in the control group was richer of TILs (5%, 5-17.5%) in comparison to cases, both in primary tumor (p = 0.035) and related metastases (p = 0.018). Although CD8+ in controls were similar to cases at primary tumor (p = 0.6498), but not at metastasis (p = 0.0223), they expressed only one part on the TILs subpopulations (p = 0.0060), while TILs in the cases at primary tumor were almost completely CD8+ (p = 0.5034). CONCLUSIONS: These findings suggest that the lack of activation of immune system in the primary tumor might influence the multifactor process of cancer progression.

6 versus 12 months of adjuvant trastuzumab in HER2+ early breast cancer: A systematic review and meta-analysis.

BACKGROUND: Adjuvant trastuzumab improves survival outcomes of human epidermal receptor 2 positive early breast cancer patients. Currently, administration of 12 months adjuvant trastuzumab is the standard therapy. However, whether 6 months treatment is non-inferior to the standard 12 months treatment remains controversial. METHODS: Relevant records were searched in PubMed, Cochrane Library, Web of Science, and EMBASE through Jan 14, 2020. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) for disease-free survival (DFS) and overall survival (OS) were meta-analyzed. The primary endpoint was DFS with a non-inferiority hazard margin of 1.2 and the second was OS with 1.43. RESULTS: Three randomized clinical studies met the inclusion criteria, including 3974 patients in 6 months group and 3976 in 12 months group. HR for DFS was 1.18 (95% CI 0.97-1.44, P = .09), with the non-inferiority margin comprised in the 95% CI. HR for OS was 1.14 (95% CI 0.98-1.32, P= .08), whereas the upper limit of 95% CI did not exceed the non-inferiority hazard margin. CONCLUSION: Our analysis failed to show that 6 months treatment was non-inferior to 12 months treatment in improving the DFS. Although the non-inferiority of the 6-month adjuvant trastuzumab treatment was found for OS, considering that breast cancer patients should receive additional systematic therapies when disease progression or relapse happens, we suggest that 12 months adjuvant trastuzumab treatment should remain the standard therapeutic strategy for patients with early human epidermal receptor 2 positive breast cancer.

Prognostic significance of PD-L1-positive cancer-associated fibroblasts in patients with triple-negative breast cancer.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are some of the most abundant components of the tumour microenvironment. A recent study suggested that in some cancers, CAFs express programmed death ligand 1 (PD-L1), which can act as a prognostic marker. The aim of this study was to investigate the clinicopathological significance of CAF PD-L1 expression in patients with triple-negative breast cancer (TNBC) and to identify the most suitable primary antibody for immunostaining for CAF PD-L1. METHODS: Immunohistochemical staining (primary antibodies of 73-10, SP142, and E1L3N) and tissue microarrays were used to analyse the expression profiles of PD-L1 in CAF in 61 patients with TNBC who underwent surgery. Overall survival (OS) was compared based on CAF PD-L1 expression, and the risk factors for OS were analysed. The relationship between clinicopathological parameters and survival was also examined. RESULTS: Thirty-four (55.7%) patients were positive for CAF PD-L1 (73-10) expression. Compared with CAF PD-L1 negativity, there was a significant correlation between CAF PD-L1 positivity and better OS (p = 0.029). CAF PD-L1 expression, evaluated using SP-142 or E1L3N, did not correlate with OS. CAF PD-L1-positivity (73-10) correlated significantly with better prognosis in multivariate analyses (hazard ratio: 0.198; 95% confidence interval: 0.044-0.891; p = 0.035). CONCLUSIONS: CAF PD-L1 expression is a novel marker for a better prognosis of patients with TNBC, and the 73-10 assay may be suitable for immunostaining CAF PD-L1.