PDL1 expression in inflammatory breast cancer is frequent and predicts for the pathological response to chemotherapy

Inflammatory breast cancer microenvironment repertoire based on DNA methylation data deconvolution reveals actionable targets to enhance the treatment efficacy

BACKGROUND

Although the clinical signs of inflammatory breast cancer (IBC) resemble acute inflammation, the role played by infiltrating immune and stromal cells in this aggressive disease is uncharted. The tumor microenvironment (TME) presents molecular alterations, such as epimutations, prior to morphological abnormalities. These changes affect the distribution and the intricate communication between the TME components related to cancer prognosis and therapy response. Herein, we explored the global DNA methylation profile of IBC and surrounding tissues to estimate the microenvironment cellular composition and identify epigenetically dysregulated markers.

METHODS

We used the HiTIMED algorithm to deconvolve the bulk DNA methylation data of 24 IBC and six surrounding non-tumoral tissues (SNT) (GSE238092) and determine their cellular composition. The prognostic relevance of cell types infiltrating IBC and their relationship with clinicopathological variables were investigated. CD34 (endothelial cell marker) and CD68 (macrophage marker) immunofluorescence staining was evaluated in an independent set of 17 IBC and 16 non-IBC samples.

RESULTS

We found lower infiltration of endothelial, stromal, memory B, dendritic, and natural killer cells in IBC than in SNT samples. Higher endothelial cell (EC) and stromal cell content were related to better overall survival. EC proportions positively correlated with memory B and memory CD8+ T infiltration in IBC. Immune and EC markers exhibited distinct DNA methylation profiles between IBC and SNT samples, revealing hypermethylated regions mapped to six genes (CD40, CD34, EMCN, HLA-G, PDPN, and TEK). We identified significantly higher CD34 and CD68 protein expression in IBC compared to non-IBC.

CONCLUSIONS

Our findings underscored cell subsets that distinguished patients with better survival and dysregulated markers potentially actionable through combinations of immunotherapy and epigenetic drugs.

The Immune Response of Cancer Cells in Breast and Gynecologic Neoplasms

Cancer diseases constitute a major health problem which leads to the death of millions of people annually. They are unique among other diseases because cancer cells can perfectly adapt to the environment that they create themselves. This environment is usually highly hostile and for normal cells it would be hugely difficult to survive, however neoplastic cells not only can survive but also manage to proliferate. One of the reasons is that they can alter immunological pathways which allow them to be flexible and change their phenotype to the one needed in specific conditions. The aim of this paper is to describe some of these immunological pathways that play significant roles in gynecologic neoplasms as well as review recent research in this field. It is of high importance to possess extensive knowledge about these processes, as greater understanding leads to creating more specialized therapies which may prove highly effective in the future.

Inflammatory breast cancer: An overview about the histo-pathological aspect and diagnosis

Inflammatory Breast Cancer (IBC) is a rare and aggressive form of locally advanced breast cancer, classified as stage T4d according to the tumor-node-metastasis staging criteria. This subtype of breast cancer is known for its rapid progression and significantly lower survival rates compared to other forms of breast cancer. Despite its distinctive clinical features outlined by the World Health Organization, the histopathological characteristics of IBC remain not fully elucidated, presenting challenges in its diagnosis and treatment. Histologically, IBC tumors often exhibit a ductal phenotype, characterized by emboli composed of pleomorphic cells with a high nuclear grade. These emboli are predominantly found in the papillary and reticular dermis of the skin overlaying the breast, suggesting a primary involvement of the lymphatic vessels. The tumor microenvironment in IBC is a complex network involving various cells such as macrophages, monocytes, and predominantly T CD8+ lymphocytes, and elements including blood vessels and extracellular matrix molecules, which play a pivotal role in the aggressive nature of IBC. A significant aspect of IBC is the frequent loss of expression of hormone receptors like estrogen and progesterone receptors, a phenomenon that is still under active investigation. Moreover, the overexpression of ERBB2/HER2 and TP53 in IBC cases is a topic of ongoing debate, with studies indicating a higher prevalence in IBC compared to non-inflammatory breast cancer. This overview seeks to provide a comprehensive understanding of the histopathological features and diagnostic approaches to IBC, emphasizing the critical areas that require further research.

Deciphering the molecular biology of inflammatory breast cancer through molecular characterization of patient samples and preclinical models

Inflammatory breast cancer is an aggressive subtype of breast cancer with dismal patient prognosis and a unique clinical presentation. In the past two decades, molecular profiling technologies have been used in order to gain insight into the molecular biology of IBC and to search for possible targets for treatment. Although a gene signature that accurately discriminates between IBC and nIBC patient samples and preclinical models was identified, the overall genomic and transcriptomic differences are small and ambiguous, mainly due to the limited sample sizes of the evaluated patient series and the failure to correct for confounding effects of the molecular subtypes. Nevertheless, data collected over the past 20 years by independent research groups increasingly support the existence of several IBC-specific biological characteristics. In this review, these features are classified as established, emerging and conceptual hallmarks based on the level of evidence reported in the literature. In addition, a synoptic model is proposed that integrates all hallmarks and that can explain how cancer cell intrinsic mechanisms (i.e. NF-κB activation, genomic instability, MYC-addiction, TGF-β resistance, adaptive stress response, chromatin remodeling, epithelial-to-mesenchymal transition) can contribute to the establishment of the dynamic immune microenvironment associated with IBC. It stands to reason that future research projects are needed to further refine (parts of) this model and to investigate its clinical translatability.

Scoparone attenuates PD-L1 expression in human breast cancer cells by MKP-3 upregulation

Breast cancer is a frequently occurring malignant tumor that is one of the leading causes of cancer-related deaths in women worldwide. Monoclonal antibodies that block programed cell death 1 (PD-1)/programed cell death ligand 1 (PD-L1) - a typical immune checkpoint - are currently the recommended standard therapies for many advanced and metastatic tumors such as triple-negative breast cancer. However, some patients develop drug resistance, leading to unfavorable treatment outcomes. Therefore, other approaches are required for anticancer treatments, such as downregulation of PD-L1 expression and promotion of degradation of PD-L1. Scoparone (SCO) is a bioactive compound isolated from Artemisia capillaris that exhibits antitumor activity. However, the effect of SCO on PD-L1 expression in cancer has not been confirmed yet. This study aimed to evaluate the role of SCO in PD-L1 expression in breast cancer cells in vitro. Our results show that SCO downregulated PD-L1 expression in a dose-dependent manner, via AKT inhibition. Interestingly, SCO treatment did not alter PTEN expression, but increased the expression of mitogen-activated protein kinase phosphatase-3 (MKP-3). In addition, the SCO-induced decrease in PD-L1 expression was reversed by siRNA-mediated MKP-3 knockdown. Collectively, these findings suggest that SCO inhibited the expression of PD-L1 in breast cancer cells by upregulating MKP-3 expression. Therefore, SCO may serve as an innovative combinatorial agent for cancer immunotherapy.

Immunotherapy for inflammatory breast cancer: current evidences and future perspectives

PURPOSE OF REVIEW

Inflammatory breast cancer (IBC) is the most fatal type presentation of clinical breast cancer. The immune tumor microenvironment (TME) of IBC is characterized by signals of immune evasion but suggests actionable vulnerability to immune-checkpoint inhibitors (ICIs). In this review, we aimed to summarize the most important preclinical evidences of IBC immune-vulnerability and the first data from clinical trials evaluating ICIs in IBC.

RECENT FINDINGS

IBC is characterized by a preexisting active immune TME suppressed by mechanisms of immune-escape, including inhibitory immune-checkpoints, whose expression is higher than in non-IBC. Clinical trials evaluating ICIs in patients with IBC are burdened by slow accrual and low enrollment.

SUMMARY

Because of the limited data from clinical trials, no conclusions about the activity of ICIs in IBC can be drawn. Ongoing clinical trials are assessing many promising ICI-based combination approaches. An enhanced multicenter collaboration to evaluate ICIs in patients with this aggressive form of disease and to improve clinical outcomes is required.

The immunogram of inflammatory breast cancer

Inflammatory breast cancer (IBC) is the most aggressive and fatal clinical presentation of breast cancer. Despite the term "inflammatory", based on the clinical presentation, IBC is biologically driven by an immunosuppressive tumor microenvironment (TME). Whether IBC can be switched into an immune-inflamed TME by immune-checkpoint inhibitors (ICIs) is a matter of debate. Presently, measurable biomarkers of IBC-TME have never been synthetized into a comprehensive portray of the immune-milieu (i.e., an immunogram), describing the immune-vulnerability of IBC and potentially predicting the response to ICIs. We propose an immunogram for IBC, based on preclinical and clinical studies, including six parameters: the presence of immune-effector cells, of immune-suppressive cells and of immune checkpoints, the general immune status, the activation of immune-suppressive pathways, the tumor foreignness. The IBC immunogram suggests the existence of a preexisting immune TME that is suppressed by mechanisms of immune-escape but might be restored by ICIs. The combination of chemotherapy and ICIs in patients with IBC is based on a strong biological rationale. However, the design and the development of clinical trials assessing the incorporation of ICIs raise many methodological and practical issues. In parallel with the further comprehension of IBC biology, the prospective validation and integration of biomarkers predictive of response to ICIs are warranted.

PD-L1 Expression in Triple-negative Breast Cancer-a Comparative Study of 3 Different Antibodies

BACKGROUND

Assessment of programmed death protein-ligand 1 (PD-L1) in triple-negative breast cancer (TNBC) has entered daily practice to identify patients eligible for treatment with immune checkpoint inhibitors. However, different antibodies and different cut-offs for PD-L1 positivity are used, and the interchangeability of these methods is not clear. The aim of our study was to analyze whether different PD-L1 antibodies can be used interchangeably to identify TNBC patients as PD-L1 positive.

METHODS

A tissue microarray encompassing 147 TNBC cases was immunohistochemically analyzed using 3 different antibodies against PD-L1: SP142, SP263, and E1L3N. PD-L1 positivity was determined as ≥1% of positive tumor-associated immune cells. The staining patterns of the 3 antibodies were compared and correlated with clinicopathological data.

RESULTS

A total of 84 cases were evaluable for PD-L1 analysis with all 3 antibodies. PD-L1 was positive in 50/84 patients (59.5%) with SP263, in 44/84 (52.4%) with E1L3N, and in 29/84 (34.5%) with SP142. There was no statistical difference between the performance of SP263 and E1L3N, but both antibodies stained significantly more cases than the SP142 antibody.

CONCLUSIONS

Our results show that the 3 PD-L1 antibodies identify different TNBC patient subgroups as PD-L1 positive and, therefore cannot be used interchangeably. Additional studies are needed to further investigate the use and impact of different PD-L1 antibody clones for predictive selection of TNBC patients for treatment with immune checkpoint inhibitors.

Breast cancer vaccines: New insights into immunomodulatory and nano-therapeutic approaches

Breast cancer (BC) is known to be a highly heterogeneous disease that is clinically subdivided into four primary molecular subtypes, each having distinct morphology and clinical implications. These subtypes are principally defined by hormone receptors and other proteins involved (or not involved) in BC development. BC therapeutic vaccines [including peptide-based vaccines, protein-based vaccines, nucleic acid-based vaccines (DNA/RNA vaccines), bacterial/viral-based vaccines, and different immune cell-based vaccines] have emerged as an appealing class of cancer immunotherapeutics when used alone or combined with other immunotherapies. Employing the immune system to eliminate BC cells is a novel therapeutic modality. The benefit of active immunotherapies is that they develop protection against neoplastic tissue and readjust the immune system to an anti-tumor monitoring state. Such immunovaccines have not yet shown effectiveness for BC treatment in clinical trials. In recent years, nanomedicines have opened new windows to increase the effectiveness of vaccinations to treat BC. In this context, some nanoplatforms have been designed to efficiently deliver molecular, cellular, or subcellular vaccines to BC cells, increasing the efficacy and persistence of anti-tumor immunity while minimizing undesirable side effects. Immunostimulatory nano-adjuvants, liposomal-based vaccines, polymeric vaccines, virus-like particles, lipid/calcium/phosphate nanoparticles, chitosan-derived nanostructures, porous silicon microparticles, and selenium nanoparticles are among the newly designed nanostructures that have been used to facilitate antigen internalization and presentation by antigen-presenting cells, increase antigen stability, enhance vaccine antigenicity and remedial effectivity, promote antigen escape from the endosome, improve cytotoxic T lymphocyte responses, and produce humoral immune responses in BC cells. Here, we summarized the existing subtypes of BC and shed light on immunomodulatory and nano-therapeutic strategies for BC vaccination. Finally, we reviewed ongoing clinical trials on BC vaccination and highlighted near-term opportunities for moving forward.

Bilateral Inflammatory Breast Cancer That Developed Two Years after Treatment for Triple-negative Breast Cancer

A 66-year-old woman underwent partial mastectomy and a sentinel lymph node biopsy for left breast cancer; the pathological diagnosis was invasive ductal carcinoma (pT1aN0, pStage I, triple-negative subtype). Postoperative radiotherapy was performed. Two years later, she developed redness and induration at both breasts. The diagnosis was bilateral inflammatory breast cancer. After four cycles of dose-dense epirubicin and cyclophosphamide followed by 12 weekly paclitaxel cycles, bilateral total mastectomy and axillary lymph node dissection were performed. At the one-year follow-up after undergoing operation and radiotherapy, she remained alive without recurrence. Dose-dense treatment regimens may help patients achieve complete resection without short-term recurrence.

A Novel Prognostic Ferroptosis-Related lncRNA Signature Associated with Immune Landscape in Invasive Breast Cancer

Breast cancer (BC) represents the most common form of malignant tumors in women. However, the effectiveness of BC immunotherapy remains very low. Ferroptosis is a recently described form of programmed cell death which has unique characteristics, and associated long-chain noncoding RNAs (lncRNA) are thought to influence the occurrence and development of a variety of tumors. We identified 1,636 lncRNAs associated with ferroptosis in BC patients. 299 differentially expressed ferroptosis-related lncRNAs were subjected to univariate, LASSO regression, and multivariate Cox regression analyses to construct a ten ferroptosis-related lncRNA signature. This ten ferroptosis-related lncRNA signature performed very well in predicting survival of BC patients, and the risk score of the mRNA signature was identified as an independent prognostic factor in this cancer entity. In addition, the signature could be used to predict the immune landscape of BC patients. Low-risk patients had enriched immune-related pathways and more infiltration of most types of immune cells. The signature was also associated with the tumor mutation burden in BC. The results have allowed us to assess the potential for immunotherapy targets exposed by this model. The ferroptosis-related lncRNA risk model reported in the current study has clinical utility in BC prognosis and predicted immunotherapy response.

Nanomedicine as a Promising Tool to Overcome Immune Escape in Breast Cancer

Breast cancer is the most common type of malignancy and leading cause of cancer death among women worldwide. Despite the current revolutionary advances in the field of cancer immunotherapy, clinical response in breast cancer is frequently below expectations, in part due to various mechanisms of cancer immune escape that produce tumor variants that are resistant to treatment. Thus, a further understanding of the molecular events underlying immune evasion in breast cancer may guarantee a significant improvement in the clinical success of immunotherapy. Furthermore, nanomedicine provides a promising opportunity to enhance the efficacy of cancer immunotherapy by improving the delivery, retention and release of immunostimulatory agents in targeted cells and tumor tissues. Hence, it can be used to overcome tumor immune escape and increase tumor rejection in numerous malignancies, including breast cancer. In this review, we summarize the current status and emerging trends in nanomedicine-based strategies targeting cancer immune evasion and modulating the immunosuppressive tumor microenvironment, including the inhibition of immunosuppressive cells in the tumor area, the activation of dendritic cells and the stimulation of the specific antitumor T-cell response.

Prognostic Value of Programmed Death Ligand-1 Expression in Solid Tumors Irrespective of Immunotherapy Exposure: A Systematic Review and Meta-Analysis

BACKGROUND

The programmed cell death-1/programmed cell death ligand-1 (PD-L1) pathway, which plays a crucial role in cancer immune surveillance, is the target of several approved immunotherapeutic agents and is used as a predictive biomarker in some solid tumors. However, its use as a prognostic marker (i.e., regardless of therapy used) is not established clearly with available data demonstrating inconsistent prognostic impact of PD-L1 expression in solid tumors.

METHODS

We conducted a systematic literature search of electronic databases and identified publications exploring the effect of PD-L1 expression on overall survival and/or disease-free survival. Hazard ratios were pooled in a meta-analysis using generic inverse-variance and random-effects modeling. We used the Deeks method to explore subgroup differences based on disease site, stage of disease, and method of PD-L1 quantification.

RESULTS

One hundred and eighty-six studies met the inclusion criteria. Programmed cell death ligand-1 expression was associated with worse overall survival (hazard ratio 1.33, 95% confidence interval 1.26-1.39; p < 0.001). There was significant heterogeneity between disease sites (subgroup p = 0.002) with pancreatic, hepatocellular, and genitourinary cancers associated with the highest magnitude of adverse outcomes. Programmed cell death ligand-1 was also associated with worse overall disease-free survival (hazard ratio 1.19, 95% confidence interval 1.09-1.30; p < 0.001). Stage of disease did not significantly affect the results (subgroup p = 0.52), nor did the method of quantification via immunohistochemistry or messenger RNA (subgroup p = 0.70).

CONCLUSIONS

High expression of PD-L1 is associated with worse survival in solid tumors albeit with significant heterogeneity among tumor types. The effect is consistent in early-stage and metastatic disease and is not sensitive to method of PD-L1 quantification. These data can provide additional information for the counseling of patients with cancer about prognosis.

Inflammatory breast cancer with excellent response to pembrolizumab-chemotherapy combination: A case report

Inflammatory breast cancer (IBC) is a rare variety of breast cancer accounting for two percent of breast cancer diagnoses in the United States. It is characterized by peau d'orange, breast edema and erythema on physical examination and dermal lymphatic invasion by tumor emboli on histological examination. Micrometastases to lymphatics and bone marrow at the time of diagnosis and angiogenic properties of IBC explain the high propensity of this cancer to relapse and metastasize, its aggressiveness and poor prognosis. Preoperative sequential anthracycline and taxane (plus trastuzumab and pertuzumab if HER2-positive) based chemotherapy is the current standard of care for IBC. We herein report a case of stage IIIC triple-negative IBC treated with pembrolizumab plus chemotherapy based neoadjuvant therapy with a complete clinical and complete pathological response. This is the first case of triple-negative IBC treated with this regimen reported in the literature, thereby providing clinical data on the tolerability and efficacy of pembrolizumab plus chemotherapy based neoadjuvant regimen for the treatment of IBC.

Early on-treatment transcriptional profiling as a tool for improving pathological response prediction in HER2-positive inflammatory breast cancer

Background

Inflammatory breast cancer (IBC) is a rare and understudied disease, with 40% of cases presenting with human epidermal growth factor receptor 2 (HER2)-positive subtype. The goals of this study were to (i) assess the pathologic complete response (pCR) rate of short-term neoadjuvant dual-HER2-blockade and paclitaxel, (ii) contrast baseline and on-treatment transcriptional profiles of IBC tumor biopsies associated with pCR, and (iii) identify biological pathways that may explain the effect of neoadjuvant therapy on tumor response.

Patients and Methods

A single-arm phase II trial of neoadjuvant trastuzumab (H), pertuzumab (P), and paclitaxel for 16 weeks was completed among patients with newly diagnosed HER2-positive IBC. Fresh-frozen tumor biopsies were obtained pretreatment (D1) and 8 days later (D8), following a single dose of HP, prior to adding paclitaxel. We performed RNA-sequencing on D1 and D8 tumor biopsies, identified genes associated with pCR using differential gene expression analysis, identified pathways associated with pCR using gene set enrichment and gene expression deconvolution methods, and compared the pCR predictive value of principal components derived from gene expression profiles by calculating and area under the curve for D1 and D8 subsets.

Results

Twenty-three participants were enrolled, of whom 21 completed surgery following neoadjuvant therapy. Paired longitudinal fresh-frozen tumor samples (D1 and D8) were obtained from all patients. Among the 21 patients who underwent surgery, the pCR and the 4-year disease-free survival were 48% (90% CI 0.29-0.67) and 90% (95% CI 66-97%), respectively. The transcriptional profile of D8 biopsies was found to be more predictive of pCR (AUC = 0.91, 95% CI: 0.7993-1) than the D1 biopsies (AUC = 0.79, 95% CI: 0.5905-0.9822).

Conclusions

In patients with HER2-positive IBC treated with neoadjuvant HP and paclitaxel for 16 weeks, gene expression patterns of tumor biopsies measured 1 week after treatment initiation not only offered different biological information but importantly served as a better predictor of pCR than baseline transcriptional analysis.

Trial Registration

ClinicalTrials.gov identifier: NCT01796197 (https://clinicaltrials.gov/ct2/show/NCT01796197); registered on February 21, 2013.

Differential effects of CD20+ B cells and PD-L1+ immune cells on pathologic complete response and outcome: comparison between inflammatory breast cancer and locally advanced breast cancer patients

PURPOSE

This study evaluated epidemiologic and immune factors associated with pathologic complete response (pCR), breast cancer-specific survival (BCSS) and disease-free survival (DFS) outcomes in inflammatory (IBC) and locally advanced breast cancer (LABC) patients.

METHODS

Tumor-infiltrating lymphocytes (TILs) and CD20+ B-cell frequencies (CD20+), and PD-L1 expression on tumor (PD-L1+carcinoma cells) and immune (PD-L1+TILs) cells were analyzed by immunohistochemistry along with clinicopathologic factors as modifiers of pCR and outcomes in 221 IBC and 162 LABC patients. Analysis included Kaplan-Meier curves and Cox proportional hazard models.

RESULTS

IBC and LABC display similar levels of TILs, CD20+, and combined CD20+ and PD-L1+TILs (CD20+PD-L1+TILs), while LABC contained more PD-L1+TILs and PD-L1+ carcinoma cells. Absence of lymphovascular involvement, high TILs, PD-L1+ carcinoma cells, and combined CD20+ and PD-L1+ carcinoma cells correlated with pCR in IBC and LABC patients. High PD-L1+TILs correlated with pCR only in LABC; less lymph node involvement at diagnosis, CD20+ and CD20+PD-L1+TILs correlated with pCR only in IBC (P < 0.04, all comparisons). Achievement of pCR in IBC and LABC patients correlated with BCSS and DFS (P < 0.02). In multivariate analyses, pCR remained an independent prognostic factor of improved DFS in IBC and LABC patients, but of BCSS in only LABC. CD20+PD-L1+TILs remained an independent prognostic factor of improved DFS and BCSS only in IBC.

CONCLUSION

CD20+PD-L1+TILs are an independent prognostic biomarker of improved outcomes in IBC, but not LABC. Selecting IBC patients by CD20 and PD-L1 status could stratify patients and potentially identify those in whom activating CD20 agents and anti-PD-1/PD-L1 therapy could be explored.

Clinical impact of PD-L1 expression in triple-negative breast cancer patients with residual tumor burden after neoadjuvant chemotherapy

BACKGROUND

Studies on PD-L1 expression in breast cancer have gained importance in recent years, especially in triple-negative breast cancer (TNBC). Our aim was to analyze the differential expression of PD-L1 to explore its correlation with response to neoadjuvant chemotherapy (NACT) and patient survival.

METHODS

PD-L1 expression was evaluated immunohistochemically (Ventana SP263 clone kit) by staining tumor specimen. PD-L1 positivity was defined as membranous staining > 1%, > 5%, > 10%, and > 20% on either tumor cell (TC) and /or immune cell (IC).

RESULTS

Fifty patients with locally advanced TNBC, who had a partial response to NACT, were included in the study. PD-L1 staining was observed in TCs in 25 patients (50%) and in ICs in 23 patients (46%) when PD-L1 > 1% was considered positive. Patients with PD-L1 positivity on ICs were more likely to respond to chemotherapy as measured by "MD Anderson Cancer Center Residual Cancer Burden Index" (14/22, 63.6% vs. 10/27, 37%, p = 0.064). The 5-year disease-free survival (DFS) and disease-specific survival (DSS) rates were 46.3% and 51.4%, respectively. A high (> 20%) tumoral PD-L1 positivity was associated with a better DFS and DSS.

CONCLUSIONS

Studies in the literature mostly focused on PD-L1 expression in inflammatory cells. However, our results suggest that patients with a high PD-L1 expression on TCs were more likely to have a better outcome. Since patients with residual tumor burden who express PD-L1 on TILs were more likely to respond to NACT, an immune checkpoint inhibitor therapy in addition to NACT would be an important option for TNBC with locally advanced disease.

Genetic Variants and Tumor Immune Microenvironment: Clues for Targeted Therapies in Inflammatory Breast Cancer (IBC)

To better understand the etiology of inflammatory breast cancer (IBC) and identify potential therapies, we studied genomic alterations in IBC patients. Targeted, next-generation sequencing (NGS) was performed on cell-free DNA (cfDNA) (n = 33) and paired DNA from tumor tissues (n = 29) from 32 IBC patients. We confirmed complementarity between cfDNA and tumor tissue genetic profiles. We found a high incidence of germline variants in IBC patients that could be associated with an increased risk of developing the disease. Furthermore, 31% of IBC patients showed deficiencies in the homologous recombination repair (HRR) pathway (BRCA1, BRCA2, PALB2, RAD51C, ATM, BARD1) making them sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. We also characterized the tumor-infiltrating lymphocytes (TILs) in tumor tissue biopsies by studying several markers (CD4, CD8, FoxP3, CD20, PD-1, and PD-L1) through immunohistochemistry (IHC) staining. In 7 of 24 (29%) patients, tumor biopsies were positive for PD-L1 and PD-1 expression on TILs, making them sensitive to PD-1/PD-L1 blocking therapies. Our results provide a rationale for considering PARP inhibitors and PD-1/PDL1 blocking immunotherapy in qualifying IBC patients.

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.

Effect of Primary Systemic Therapy on PD-1, PD-L1, and PD-L2 mRNA Expression in Advanced Breast Cancer

OBJECTIVE

The association between PD-1, PD-L1, and PD-L2 expression and prognosis has been extensively studied in various cancers but remained controversial in breast cancer. Besides, little is known about the prognostic value of PD-1, PD-L1, and PD-L2 upregulation or downregulation following systemic therapy (chemotherapy and hormonal therapy) in breast cancer. Therefore, we aim to investigate the change of PD-1, PD-L1, and PD-L2 expression in mRNA level after primary systemic therapy in breast cancer patients and its clinical implications.

METHODS

Expression of PD-1, PD-L1, and PD-L2 mRNA were measured before-after chemotherapy and hormonal therapy with real-time PCR in 80 advanced breast cancer patients. The correlation between alteration of PD-1, PD-L1, and PD-L2 expression and clinicopathological characteristics as well as overall survival was also statistically analyzed.

RESULTS

Chemotherapy and hormonal therapy altered PD-1, PD-L1, and PD-L2 expression in breast cancer with most patients have an increase expression. As much as 57.1%, 62.9% and 60% patients have an increase PD-1, PD-L1, and PD-L2 expression after chemotherapy, while 60%, 60%, and 64% patients have an increase PD-1, PD-L1, and PD-L2 expression after hormonal therapy. Alteration of PD-1, PD-L1, and PD-L2 expression was not correlated with all clinicopathological characteristics. Increase in PD-1, PD-L1, and PD-L2 expression was significantly associated with better OS (p=0.031, p=0.019, and p=0.019 for PD-1, PD-L1, and PD-L2, respectively), which remained significant in multivariate analysis including age, stage, primary systemic therapy, histology grade, subtype and primary tumor histology (HR PD-1 0.5 (95% CI 0.28-0.88) p=0.031; HR PD-L1 0.43 (95% CI 0.24-0.8) p=0.019; HR PD-L2 (95% CI 0.24-0.87) p=0.019).  Conclusion: Expression of PD-1, PD-L1, and PD-L2 in breast cancer patients is mostly enhanced after chemotherapy and hormonal therapy, and the enhancement is associated with good OS. This result revealed the potential of measuring PD-1, PD-L1, and PD-L2 mRNA expression in predicting clinical outcome.

Immune landscape of inflammatory breast cancer suggests vulnerability to immune checkpoint inhibitors

Background. Anti-PD1/PDL1 immune checkpoint inhibitors (ICIs) showed promising results in breast cancer, and exploration of additional actionable immune checkpoints is ongoing. Inflammatory breast cancer (IBC) is an aggressive form of disease, the immune tumor microenvironment (TME) of which is poorly known. We aimed at providing the first comprehensive immune portrait of IBCs. Methods. From the gene expression profiles of 137 IBC and 252 non-IBC clinical samples, we measured the fractions of 22 immune cell types, expression of signatures associated with tertiary lymphoid structures (TLS) and with the response to ICIs (T cell-inflamed signature: TIS) and of 18 genes coding for major actionable immune checkpoints. The IBC/non-IBC comparison was adjusted upon the clinicopathological variables. Results. The immune profiles of IBCs were heterogeneous. CIBERSORT analysis showed profiles rich in macrophages, CD8+ and CD4 + T-cells, with remarkable similarity with melanoma TME. The comparison with non-IBCs showed significant enrichment in M1 macrophages, γδ T-cells, and memory B-cells. IBCs showed higher expression of TLS and TIS signatures. The TIS signature displayed values in IBCs close to those observed in other cancers sensitive to ICIs. Two-thirds of actionable immune genes (HAVCR2/TIM3, CD27, CD70, CTLA4, ICOS, IDO1, LAG3, PDCD1, TNFRSF9, PVRIG, CD274/PDL1, and TIGIT) were overexpressed in IBCs as compared to normal breast and two-thirds were overexpressed in IBCs versus non-IBCs, with very frequent co-overexpression. For most of them, the overexpression was associated with better pathological response to chemotherapy. Conclusion. Our results suggest the potential higher vulnerability of IBC to ICIs. Clinical trials.

Progress for Immunotherapy in Inflammatory Breast Cancer and Emerging Barriers to Therapeutic Efficacy

Simple Summary

Despite recent advances in the treatment of other breast cancer subtypes, inflammatory breast cancer (IBC) remains a significant clinical challenge, with an overall 5-year survival rate of 39%. Though immunotherapy has shown remarkable efficacy in other difficult-to-treat cancers, such approaches have yet to show substantial therapeutic efficacy in IBC. Here, we summarize the known immune composition of IBC tumors, as well as past and present efforts to advance immunotherapy in the treatment of IBC.

Abstract

Inflammatory breast cancer (IBC) is a rare and aggressive subtype of breast cancer that carries a particularly poor prognosis. Despite the efficacy of immunotherapy in other difficult to treat forms of breast cancer, progress for immunotherapy in IBC has been difficult. Though immunotherapy has been under clinical investigation in IBC since the 1970s, few approaches have shown significant therapeutic efficacy, and no immunotherapy regimens are currently used in the treatment of IBC. Here, we provide a comprehensive summary of what is known about the immune composition of IBC tumors, clinical and basic science evidence describing the role for immune checkpoints such as PD-L1 in IBC pathobiology, as well as past and present attempts to advance ICIs in the treatment of IBC.

Clinicopathological and prognostic significance of programmed cell death ligand 1 expression in patients diagnosed with breast cancer: meta-analysis

BACKGROUND

Uncertainty exists regarding the clinical relevance of programmed cell death ligand 1 (PD-L1) expression in breast cancer.

METHODS

A systematic review was performed in accordance with PRISMA guidelines. Observational studies that compared high versus low expression of PD-L1 on breast cancer cells were identified. Log hazard ratios (HRs) for disease-free and overall survival and their standard errors were calculated from Kaplan-Meier curves or Cox regression analyses, and pooled using the inverse-variance method. Dichotomous variables were pooled as odds ratios (ORs) using the Mantel-Haenszel method.

RESULTS

Sixty-five studies with 19 870 patients were included; 14 404 patients were classified as having low and 4975 high PD-L1 expression. High PD-L1 was associated with achieving a pathological complete response following neoadjuvant chemotherapy (OR 3.30, 95 per cent confidence interval 1.19 to 9.16; P < 0.01; I2 = 85 per cent). Low PD-L1 expression was associated with human epidermal growth factor receptor 2 (OR 3.98, 1.81 to 8.75; P < 0.001; I2 = 96 per cent) and luminal (OR 14.93, 6.46 to 34.51; P < 0.001; I2 = 99 per cent) breast cancer subtypes. Those with low PD-L1 had favourable overall survival rates (HR 1.30, 1.05 to 1.61; P = 0.02; I2 = 85 per cent).

CONCLUSION

Breast cancers with high PD-L1 expression are associated with aggressive clinicopathological and immunohistochemical characteristics and are more likely to achieve a pathological complete response following neoadjuvant chemotherapy. These breast cancers are, however, associated with worse overall survival outcomes.

New Treatment Strategies for the Inflammatory Breast Cancer

OPINION STATEMENT

Inflammatory breast cancer (IBC) remains the most aggressive type of breast cancer. During the past decade, enormous progress has been made to refine diagnostic criteria and establish multimodality treatment strategies as keys for the improvement of survival outcomes. Multiple genomic studies enabled a better understanding of underlying tumor biology, which is responsible for the complex and aggressive nature of IBC. Despite these important achievements, outcomes for this subgroup of patients remain unsatisfactory compared to locally advanced non-IBC counterparts. Global efforts are now focused on identifying novel strategies that will improve treatment response, prolong survival for metastatic patients, achieve superior local control, and possibly increase the cure rate for locally advanced disease. Genomic technologies constitute the most important tool that will support future clinical progress. Gene-expressing profiling of the tumor tissue and liquid biopsy are important parts of the everyday clinical practice aiming to guide treatment decisions by providing information on tumor molecular drivers or primary and acquired resistance to treatment. The International IBC expert panel and IBC International Consortium made a tremendous effort to define IBC as a distinct entity of BC, and they will continue to lead and support the research for this rare and very aggressive disease. Finally, a uniform platform is now required to develop and lead large, multi-arm, proof-of-concept clinical trials that perform rapid, focused, and cost-effective evaluations of potential novel therapeutics in IBC.

Co-Regulation of Immune Checkpoint PD-L1 with Interferon-Gamma Signaling is Associated with a Survival Benefit in Renal Cell Cancer

Background

Programmed death ligand (PD-L1)-based immune checkpoint blockade therapy for metastatic renal cell carcinoma (RCC) achieves significant response rates in a subgroup of patients. The relevance of PD-L1 gene regulation for disease outcome is not clear.

Objective

To evaluate PD-L1 expression and its dependence on interferon-γ (IFN-γ) in RCC cell lines and tissues in relation to disease outcome.

Methods and Patients

Regulation of PD-L1-mRNA and PD-L1 protein was studied in cell lines from clear cell RCC (ccRCC) and papillary RCC (pRCC) by quantitative RT-PCR and Western-blot analysis. PD-L1-mRNA correlation and gene-set enrichment analysis (GSEA) of the IFN-γ pathway were conducted with RNA-Seq from ccRCC, pRCC, and skin cutaneous melanoma (SKCM) tissue. In addition, patient overall survival (OS) and disease-free survival (DFS) (cBioPortal for Cancer Genomics) were considered.

Results

In ccRCC-like cell lines, PD-L1 was induced by canonical IFN-γ signaling, whereas in a pRCC-like cell line, PD-L1 was refractory towards IFN-γ signaling. In ccRCC and SKCM tissues, GSEA revealed significant IFN-γ pathway activation in tissue samples with high PD-L1-mRNA levels. This was not observed in pRCC tissue. ccRCC and SKMC patients with low PD-L1-mRNA levels had significantly shorter OS and DFS than those with high PD-L1-mRNA levels. In pRCC patients, no significant difference in OS and DFS with regard to PD-L1-mRNA tissue levels was obvious.

Conclusions

The findings suggest that ccRCC and pRCC differ with respect to PD-L1 regulation by IFN-γ-signaling. High PD-L1-mRNA levels in tumor tissues with a positive IFN-γ signature favorably affect OS and DFS.

Electronic supplementary material

The online version of this article (10.1007/s11523-020-00728-8) contains supplementary material, which is available to authorized users.

Update on systemic treatment for newly diagnosed inflammatory breast cancer

Background

Inflammatory breast cancer (IBC) is a rare and aggressive disease, accounting for 2-4% of new cases of breast cancer. Owing to its aggressive nature, IBC represent approximately 8-10% of breast cancer deaths. Management of IBC requires a multidisciplinary team for decision-making involving a composite of systemic treatment, surgery, and radiation, or "Trimodality Treatment." Because of the rarity of the disease, systemic therapy of IBC traditionally has been extrapolated from non-IBC clinical trials.

Aim of Review

The purpose of this review is to provide an overview of the development of systemic treatment of IBC from the past to the present by focusing on IBC clinical trials, including chemotherapy and targeted therapies.

Key Scientific Concepts of Review

We discuss their effects on pathologic complete response (pCR) and survival outcomes, the predictive markers, and the adverse events of these therapies. Further, we summarized the current standard treatment stratified by molecular subtypes based on clinical data. Finally, we discuss the future trend of systemic therapy, including immunotherapy and ongoing IBC clinical trials.

PD-L1 Expression after Neoadjuvant Chemotherapy in Triple-Negative Breast Cancers Is Associated with Aggressive Residual Disease, Suggesting a Potential for Immunotherapy

The consequences of neoadjuvant chemotherapy (NAC) for PD-L1 activity in triple-negative breast cancers (TNBC) are not well-understood. This is an important issue as PD-LI might act as a biomarker for immune checkpoint inhibitors' (ICI) efficacy, at a time where ICI are undergoing rapid development and could be beneficial in patients who do not achieve a pathological complete response. We used immunohistochemistry to assess PD-L1 expression in surgical specimens (E1L3N clone, cutoff for positivity: ≥1%) on both tumor (PD-L1-TC) and immune cells (PD-L1-IC) from a cohort of T1-T3NxM0 TNBCs treated with NAC. PD-L1-TC was detected in 17 cases (19.1%) and PD-L1-IC in 14 cases (15.7%). None of the baseline characteristics of the tumor or the patient were associated with PD-L1 positivity, except for pre-NAC stromal TIL levels, which were higher in post-NAC PD-L1-TC-positive than in negative tumors. PD-L1-TC were significantly associated with a higher residual cancer burden (p = 0.035) and aggressive post-NAC tumor characteristics, whereas PD-L1-IC were not. PD-L1 expression was not associated with relapse-free survival (RFS) (PD-L1-TC, p = 0.25, and PD-L1-IC, p = 0.95) or overall survival (OS) (PD-L1-TC, p = 0.48, and PD-L1-IC, p = 0.58), but high Ki67 levels after NAC were strongly associated with a poor prognosis (RFS, p = 0.0014, and OS, p = 0.001). A small subset of TNBC patients displaying PD-L1 expression in the context of an extensive post-NAC tumor burden could benefit from ICI treatment after standard NAC.

Transcriptome analysis of the procession from chronic pancreatitis to pancreatic cancer and metastatic pancreatic cancer

Exploring the underlying mechanisms of cancer development is useful for cancer treatment. In this paper, we analyzed the transcriptome profiles from the human normal pancreas, pancreatitis, pancreatic cancer and metastatic pancreatic cancer to study the intricate associations among pancreatic cancer progression. We clustered the transcriptome data, and analyzed the differential expressed genes. WGCNA was applied to construct co-expression networks and detect important modules. Importantly we selected the module in a different way. As the pancreatic disease deteriorates, the number of differentially expressed genes increases. The gene networks of T cells and interferon are upregulated in stages. In conclusion, the network-based study provides gradually activated gene networks in the disease progression of pancreatitis, pancreatic cancer, and metastatic pancreatic cancer. It may contribute to the rational design of anti-cancer drugs.

Immune phenotype of patients with stage IV metastatic inflammatory breast cancer

Background

Inflammatory breast cancer (IBC) is a rare but aggressive carcinoma characterized by severe erythema and edema of the breast, with many patients presenting in advanced metastatic disease. The “inflammatory” nature is not due to classic immune-mediated inflammation, but instead results from tumor-mediated blockage of dermal lymphatic ducts. Previous work has shown that expression of PD-L1 on tumor cells can suppress T cell activation in triple-negative (TN) non-IBC breast cancer. In the present work, we investigated immune parameters in peripheral blood of metastatic IBC patients to determine whether cellular components of the immune system are altered, thereby contributing to pathogenesis of the disease. These immune parameters were also compared to PD-1 and PD-L1 expression in IBC tumor biopsies.

Methods

Flow cytometry-based immune phenotyping was performed using fresh peripheral blood from 14 stage IV IBC patients and compared to 11 healthy age-similar control women. Immunohistochemistry for CD20, CD3, PD-1, and PD-L1 was performed on tumor biopsies of these metastatic IBC patients.

Results

IBC patients with Stage IV disease had lymphopenia with significant reductions in circulating T, B, and NK cells. Reductions were observed in all subsets of CD4⁺ T cells, whereas reductions in CD8⁺ T cells were more concentrated in memory subsets. Immature cytokine-producing CD56^bright NK cells expressed higher levels of FcγRIIIa and cytolytic granule components, suggesting accelerated maturation to cytolytic CD56^dim cells. Immunohistochemical analysis of tumor biopsies demonstrated moderate to high expression of PD-1 in 18.2% of patients and of PD-L1 in 36.4% of patients. Interestingly, a positive correlation was observed between co-expression levels of PD-L1 and PD-1 in tumor biopsies, and higher expression of PD-L1 in tumor biopsies correlated with higher expression of cytolytic granule components in blood CD4⁺ T cells and CD56^dim NK cells, and higher numbers of CD8⁺ effector memory T cells in peripheral blood. PD-1 expression in tumor also correlated with increased infiltration of CD20⁺ B cells in the tumor.

Conclusions

Our results suggest that while lymphocyte populations are severely compromised in stage IV IBC patients, an immune response toward the tumor had occurred in some patients, providing biological rationale to evaluate PD-1/PD-L1 immunotherapies for IBC.

Supplementary information

The online version contains supplementary material available at 10.1186/s13058-020-01371-x.

PELICAN-IPC 2015-016/Oncodistinct-003: A Prospective, Multicenter, Open-Label, Randomized, Non-Comparative, Phase II Study of Pembrolizumab in Combination With Neo Adjuvant EC-Paclitaxel Regimen in HER2-Negative Inflammatory Breast Cancer

Inflammatory breast cancer (IBC) is a highly aggressive entity with a poor outcome and relative resistance to treatment. Despite progresses achieved during the last decades, the survival remains significantly lower than non-IBC. Recent clinical trials assessing PD-1/PD-L1 inhibitors showed promising results in non-IBC. Pembrolizumab, an anti-PD-1 monoclonal antibody, revolutionized the treatment of different cancers. Several recent studies suggested a potential interest of targeting the immune system in IBC by revealing a more frequent PD-L1 expression and an enriched immune microenvironment when compared with non-IBC. Here, we describe the rationale and design of PELICAN-IPC 2015-016/Oncodistinct-003 trial, an open-label, randomized, non-comparative, phase II study assessing efficacy, and safety of pembrolizumab in combination with anthracycline-containing neoadjuvant chemotherapy in HER2-negative IBC. The trial is ongoing. The primary endpoint is the pCR rate (ypT0/Tis, ypN0) in overall population and the co-primary endpoint is safety profile during a run-in phase. Key secondary objectives include tolerability, invasive disease-free, event-free and overall survivals, as well as collection of tumor and blood samples for translational research.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ (NCT03515798).

PD-L1 regulates tumorigenesis and autophagy of ovarian cancer by activating mTORC signaling

PD-L1 is a well-known immune co-stimulatory molecule that regulates tumour cell escape from immunity by suppressing the immune response. However, the clinical significance of PD-L1 in the progression of ovarian cancer is unclear. Our study demonstrated that PD-L1 is up-regulated in ovarian tumour tissue compared with its expression level in adjacent normal tissue. Furthermore, we confirmed that PD-L1 increases the proliferation of cancer cells by activating the AKT-mTORC signalling pathway, which is also enhanced by the expression of S6K, the substrate of mTORC. In addition, PD-L1 promotes the autophagy of ovarian cancer cells by up-regulating the expression of BECN1, a crucial molecule involved in the regulation of autophagy. In conclusion, PD-L1 may provide a target for the development of a novel strategy for the treatment of ovarian cancer.

Biomarkers for Inflammatory Breast Cancer: Diagnostic and Therapeutic Utility

Inflammatory breast cancer (IBC) is a rare and highly aggressive subtype of advanced breast cancer. The aggressive behavior, resistance to chemotherapy, angiogenesis, and high metastatic potential are key intrinsic characteristics of IBC caused by many specific factors. Pathogenesis and behavior of IBC are closely related to tumor surrounding inflammatory and immune cells, blood vessels, and extracellular matrix, which are all components of the tumor microenvironment (TME). The tumor microenvironment has a crucial role in the local immune r09esponse. The communication between intrinsic and extrinsic components of IBC and the abundance of cytokines and chemokines in the TME strongly contribute to the aggressiveness and high angiogenic potential of this tumor. Critical modes of interaction are cytokine-mediated communication and direct intercellular contact between cancer cells and tumor microenvironment with a variety of pathway crosstalk. This review aimed to summarize current knowledge of predictive and prognostic biomarkers in IBC.

A high neutrophil-lymphocyte ratio and platelet-lymphocyte ratio are associated with a worse outcome in inflammatory breast cancer

Introduction

Inflammatory breast cancer (IBC) is an uncommon, but aggressive form of breast cancer that accounts for a disproportionally high fraction of breast cancer related mortality. The aim of this study was to explore the peripheral immune response and the prognostic value of blood-based biomarkers, such as the neutrophil-to-lymphocyte ratio (NLR), in a large IBC cohort.

Patients & methods

We retrospectively identified 127 IBC patients and collected lab results from in-hospital medical records. The differential count of leukocytes was determined at the moment of diagnosis, before any therapeutic intervention. A cohort of early stage (n = 108), locally advanced (n = 74) and metastatic breast cancer patients (n = 41) served as a control population.

Results

The NLR was significantly higher in IBC compared to an early stage breast cancer cohort, but no difference between IBC patients and locally advanced breast cancer patients was noted. In the metastatic setting, there was also no significant difference between IBC and nIBC. However, a high NLR (>4.0) remained a significant predictor of worse outcome in IBC patients (HR: 0.49; 95% CI: 0.24–1.00; P = .05) and a lower platelet-lymphocyte ratio (PLR) (≤210) correlated with a better disease-free survival (DFS) (HR: 0.51; 95% CI: 0.28–0.93; P = .03).

Conclusion

Patients with a high NLR (>4.0) have a worse overall prognosis in IBC, while the PLR correlated with relapse free survival (RFS). Since NLR and PLR were not specifically associated with IBC disease, they can be seen as markers of more extensive disease.

•

There is no association between NLR or PLR and inflammatory breast cancer (IBC).

•

IBC and non-inflammatory breast cancer elicit a similar peripheral immune response.

•

A high neutrophil-to-lymphocyte ratio (NLR) is associated with a worse overall survival in IBC.

•

A high platelet-lymphocyte ratio (PLR) correlates with a worse disease-free survival in IBC.

•

An elevated PLR or NLR should be seen as a marker of more extensive disease in IBC.

Programmed cell death ligand-1 and cytotoxic T cell infiltrates in metastatic cutaneous squamous cell carcinoma of the head and neck

BACKGROUND

Metastatic cutaneous squamous cell carcinoma (cSCC) carries a poor prognosis. Increased numbers of CD8+ cytotoxic T cells are associated with a favorable prognosis and programmed cell death receptor-1 is a suppressor of the CD8+ cytotoxic T cell response. We aim to define their expression in metastatic cutaneous squamous cell carcinoma.

METHODS

Cytotoxic T cell infiltrates and tumoral PD-L1 expression in lymph node metastases from patients with cSCC of the head and neck were analyzed.

RESULTS

High tumoral PD-L1 expression, intratumoral and peritumoral CD8+ cell density in metastases were significantly associated with poor primary tumor differentiation. Low PD-L1 expression, intratumoral and peritumoral CD8+ density were associated with lower grade primary tumor differentiation. Low PD-L1 expression correlated with disease progression.

CONCLUSIONS

Increased expression of PD-L1 correlates with increased CD8+ cell density. Increased expression of PD-L1 in poorly differentiated tumors may be more likely to benefit from anti PD-1/PD-L1 therapy.

Soluble PD-L1: a potential immune marker for HIV-1 infection and virological failure

Despite viral control, basal chronic inflammation and its related comorbidities remain unsolved problems among HIV-infected individuals. Soluble factors derived from myeloid cells have emerged as potent markers associated with HIV-related comorbidities and mortality. In the present report, we explored the relationship between soluble programmed death-ligand 1 (sPD-L1) and HIV-1 infection, antiretroviral therapy (ART), CD4/CD8 ratio, viral load (VL), and sexually transmitted coinfections.A prospective observational study on 49 HIV-1 infected adults.We found sPD-L1 levels were significantly higher in 49 HIV infected subjects than in 30 uninfected adults (1.05 ng/ml vs 0.52 ng/ml; P < .001). In this line, sPD-L1 levels were found to be elevated in 16 HIV infected subjects with undetectable VL compared with the uninfected subjects (0.75 ng/ml vs 0.52 ng/ml; P = .02). Thirteen ART-treated individuals with virological failure exhibited the highest sPDL1 levels, which were significantly higher than both 20 ART naïve infected individuals (1.68 ng/ml vs 0.87 ng/ml; P = .003) and the 16 ART-treated individuals with suppressed viremia (1.68 ng/ml vs 0.79 ng/ml; P = 002). Entire cohort data showed a statistically significant positive correlation between VL and sPD-L1 levels in plasma (r = 0.3; P = 036).Our findings reveal sPDL-1 as a potential biomarker for HIV infection especially interesting in those individuals with virological failure.

Silencing Signal Transducer and Activator of Transcription 3 (STAT3) and Use of Anti-Programmed Cell Death-Ligand 1 (PD-L1) Antibody Induces Immune Response and Anti-Tumor Activity

BACKGROUND The treatment of cancer is still unable to meet the needs of patients and remains a huge challenge. This study investigated the immune response and anti-cancer effect of silencing STAT3 combined with the use of anti-PD-L1 antibody. MATERIAL AND METHODS Transfected CT26.WT cells were used to subcutaneously inoculate C57B/L6 mice, which were subsequently injected with anti-PD-L1 antibody. Treated mice were examined for tumor formation and inflammation using HE staining. Tumors were investigated for apoptosis using the TUNEL assay. The expression of STAT3, PD-L1, and C-met was studied immunohistochemistrially and by using PCR and Western blot analysis. RESULTS Four weeks after inoculation, tumors were observed in the inoculated mice. HE staining showed obvious inflammation in mice injected with cells that were silenced for STAT3 and injected with PD-L1 antibody. TUNEL assay showed low level of apoptosis in mice injected with cells silenced for STAT3 or injected with PD-L1 antibody, and higher level of apoptosis following combined treatment of STAT3 silencing and PD-L1 antibody injection. Immunohistochemistry, PCR, and Western blot analyses revealed that the expression of C-met, PD-L1, and STAT3 was significantly reduced in tumors following the combined treatment. Compared with treatment of STAT3 silencing or PD-L1 antibody injection, the combined treatment enhanced apoptosis. CONCLUSIONS Silencing STAT3 and PD-L1 antibody injection in combination increased apoptosis in tumor cells and thus offers better anti-cancer activity.

Breast Cancer: A Molecularly Heterogenous Disease Needing Subtype-Specific Treatments

Breast cancer is the most commonly occurring cancer in women. There were over two-million new cases in world in 2018. It is the second leading cause of death from cancer in western countries. At the molecular level, breast cancer is a heterogeneous disease, which is characterized by high genomic instability evidenced by somatic gene mutations, copy number alterations, and chromosome structural rearrangements. The genomic instability is caused by defects in DNA damage repair, transcription, DNA replication, telomere maintenance and mitotic chromosome segregation. According to molecular features, breast cancers are subdivided in subtypes, according to activation of hormone receptors (estrogen receptor and progesterone receptor), of human epidermal growth factors receptor 2 (HER2), and or BRCA mutations. In-depth analyses of the molecular features of primary and metastatic breast cancer have shown the great heterogeneity of genetic alterations and their clonal evolution during disease development. These studies have contributed to identify a repertoire of numerous disease-causing genes that are altered through different mutational processes. While early-stage breast cancer is a curable disease in about 70% of patients, advanced breast cancer is largely incurable. However, molecular studies have contributed to develop new therapeutic approaches targeting HER2, CDK4/6, PI3K, or involving poly(ADP-ribose) polymerase inhibitors for BRCA mutation carriers and immunotherapy.

NOTCH and DNA repair pathways are more frequently targeted by genomic alterations in inflammatory than in non-inflammatory breast cancers

Inflammatory breast cancer (IBC) is the most pro‐metastatic form of breast cancer. Better understanding of its pathophysiology and identification of actionable genetic alterations (AGAs) are crucial to improve systemic treatment. We aimed to define the DNA profiles of IBC vs noninflammatory breast cancer (non‐IBC) clinical samples in terms of copy number alterations (CNAs), mutations, and AGAs. We applied targeted next‐generation sequencing (tNGS) and array‐comparative genomic hybridization (aCGH) to 57 IBC and 50 non‐IBC samples and pooled these data with four public datasets profiled using NGS and aCGH, leading to a total of 101 IBC and 2351 non‐IBC untreated primary tumors. The respective percentages of each molecular subtype [hormone receptor‐positive (HR+)/HER2−, HER2+, and triple‐negative] were 68%, 15%, and 17% in non‐IBC vs 25%, 35%, and 40% in IBC. The comparisons were adjusted for both the molecular subtypes and the American Joint Committee on Cancer (AJCC) stage. The 10 most frequently altered genes in IBCs were TP53 (63%), HER2/ERBB2 (30%), MYC (27%), PIK3CA (21%), BRCA2 (14%), CCND1 (13%), GATA3 (13%), NOTCH1 (12%), FGFR1 (11%), and ARID1A (10%). The tumor mutational burden was higher in IBC than in non‐IBC. We identified 96 genes with an alteration frequency (p < 5% and q < 20%) different between IBC and non‐IBC, independently from the molecular subtypes and AJCC stage; 95 were more frequently altered in IBC, including TP53, genes involved in the DNA repair (BRCA2) and NOTCH pathways, and one (PIK3CA) was more frequently altered in non‐IBC. Ninety‐seven percent of IBCs displayed at least one AGA. This percentage was higher than in non‐IBC (87%), notably for drugs targeting DNA repair, NOTCH signaling, and CDK4/6, whose pathways were more frequently altered (DNA repair) or activated (NOTCH and CDK4/6) in IBC than in non‐IBC. The genomic landscape of IBC is different from that of non‐IBC. Enriched AGAs in IBC may explain its aggressiveness and provide clinically relevant targets.

Programmed Cell Death Ligand 1 in Breast Cancer: Technical Aspects, Prognostic Implications, and Predictive Value

In the light of recent advances in the immunotherapy field for breast cancer (BC) treatment, especially in the triple-negative subtype, the identification of reliable biomarkers capable of improving patient selection is paramount, because only a portion of patients seem to derive benefit from this appealing treatment strategy. In this context, the role of programmed cell death ligand 1 (PD-L1) as a potential prognostic and/or predictive biomarker has been intensively explored, with controversial results. The aim of the present review is to collect available evidence on the biological relevance and clinical utility of PD-L1 expression in BC, with particular emphasis on technical aspects, prognostic implications, and predictive value of this promising biomarker. IMPLICATIONS FOR PRACTICE: In the light of the promising results coming from trials of immune checkpoint inhibitors for breast cancer treatment, the potential predictive and/or prognostic role of programmed cell death ligand 1 (PD-L1) in breast cancer has gained increasing interest. This review provides clinicians with an overview of the available clinical evidence regarding PD-L1 as a biomarker in breast cancer, focusing on both data with a possible direct impact on clinic and methodological pitfalls that need to be addressed in order to optimize PD-L1 implementation as a clinically useful tool for breast cancer management.

Pathological and molecular characteristics of inflammatory breast cancer

Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer characterized by the presence of many dermal tumor emboli in the papillary and reticular dermis of the skin overlying the breast. IBC patients, compared to other breast cancer patients, have more frequently metastatic axillary lymph nodes. IBC is often high grade, negative for hormone receptors and presents with amplification of the HER2 gene. Invasive IBC is frequently of ductal phenotype, even if a specific histological distinction for these lesions has not been described. The pathogenesis and evolution of IBC are strongly dependent upon tumor microenvironment, characterized by several macrophages/monocytes and lymphocytes. The tumor and microenvironment cells are well molecularly characterized, showing the main contributor of inflammatory pathways in tumor biology of IBC. In addition, several molecular alterations are described in this tumor, such as mutations of ERBB2, KRAS, BRAF, EGFR, PIK3CA, PTEN, AKT1, and AKT3 genes that could suggest a therapeutic stratification of IBC patients with the combination of different biological target therapies.

PDL1 expression is associated with longer postoperative, survival in adrenocortical carcinoma

Adrenocortical carcinomas (ACCs) are heterogeneous cancers associated with a very poor prognosis. The improvement of prognostic tools and systemic therapy are urgently needed. Targeting the immune system using checkpoint inhibitors such as PD1/PDL1 inhibitors is an attractive novel therapeutic strategy for poor-prognosis tumors. Multiple clinical trials are ongoing, including in advanced ACC. However, PDL1 expression has been studied in ACC in only one heterogeneous series of 28 clinical samples. Here, we have retrospectively analyzed PDL1 mRNA expression in 146 clinical ACC samples and searched for correlations between expression and biological and clinicopathological data, including post-operative disease-free survival (DFS). PDL1 mRNA expression was heterogeneous across samples. "PDL1-high" tumors were not associated with the classical prognostic variables but were associated with longer DFS in both uni- and multivariate analyses. High PDL1 mRNA expression was associated with biological signs of the cytotoxic local immune response. Supervised analysis between "PDL1-high" and "PDL1-low" tumors identified a robust 370-gene signature whose ontology analysis suggested the existence in "PDL1-high" tumors of a cytotoxic T-cell response, however, associated with some degree of T-cell exhaustion. In conclusion, PDL1 mRNA expression refines the prognostication in ACC and high expression is associated with longer DFS. Clinical validation at the protein level and functional validation are required to fully understand the role of PDL1 in ACC. Reactivation of dormant tumor-infiltrating lymphocytes by PDL1-inhibitors could represent a promising strategy in "PDL1-high" ACCs, supporting the ongoing clinical trials.

PD-L1 Acts as a Promising Immune Marker to Predict the Response to Neoadjuvant Chemotherapy in Breast Cancer Patients

BACKGROUND

Programmed death ligand 1 (PD-L1) is a negative immune stimulatory molecule that plays a key role in tumor immune escape. We analyzed the clinical value of PD-L1-positive expression in predicting the outcome of breast cancer patients and to establish its role as new biomarker to guide precise treatment.

PATIENTS AND METHODS

PubMed and Embase were searched for all original English-language articles published before January 30, 2019; all articles reported the predictive and prognostic implications of PD-L1⁺ in breast cancer. Data were analyzed by Stata SE 12 software.

RESULTS

The PD-L1⁺ rate varied from 19.7% to 77.6% in breast cancer patients. Specifically, patients with estrogen receptor-positive, progesterone receptor-positive, luminal A, luminal B, and HER2⁺ disease subtypes had lower PD-L1 expression, while the PD-L1⁺ percentages did not follow any trend in patients with Ki-67⁺, normal-like, HER2 overexpression, and basal-like subtype. In addition, PD-L1⁺ was observed to be associated with significantly improved pathologic complete response to neoadjuvant chemotherapy (odds ratio = 2.01; 95% confidence interval, 1.35-3.01; P < .05). Using PD-L1⁺ to predict pathologic response showed obvious accuracy. However, PD-L1⁺ did not show significant association with risk of higher recurrence or metastasis, or higher death risk (hazard ratio = 0.91, P = .655; hazard ratio = 1.00, P = .995).

CONCLUSION

PD-L1⁺ is a promising immune parameter with the potential to predict response to neoadjuvant chemotherapy, but it cannot indicate a higher risk of death, recurrence, or metastasis.

Inflammatory Breast Cancer: a Separate Entity

PURPOSE OF REVIEW

Inflammatory breast cancer (IBC) is an uncommon but highly aggressive subtype of breast cancer that contributes significantly to breast cancer-related mortality. In this review, we provide an overview of the clinical and molecular characteristics of IBC, and highlight some areas of need for ongoing research.

RECENT FINDINGS

The disease is characterized by florid tumor emboli that obstruct dermal lymphatics, leading to swelling and inflammation of the affected breast. Recent studies have focused on tumor cell intrinsic features, such as signaling through pathways involved in growth and stem-like behavior, as well as extrinsic features, such as the immune system, that can be leveraged to develop new potential therapies. Key efforts have led to an increase in awareness of the disease as well as new insights into IBC pathogenesis. However, there is a strong need for new therapies designed specifically for IBC, and many unanswered questions remain.

PARP1 Inhibition Radiosensitizes Models of Inflammatory Breast Cancer to Ionizing Radiation

Sustained locoregional control of disease is a significant issue in patients with inflammatory breast cancer (IBC), with local control rates of 80% or less at 5 years. Given the unsatisfactory outcomes for these patients, there is a clear need for intensification of local therapy, including radiation. Inhibition of the DNA repair protein PARP1 has had little efficacy as a single agent in breast cancer outside of studies restricted to patients with BRCA mutations; however, PARP1 inhibition (PARPi) may lead to the radiosensitization of aggressive tumor types. Thus, this study investigates inhibition of PARP1 as a novel and promising radiosensitization strategy in IBC. In multiple existing IBC models (SUM-149, SUM-190, MDA-IBC-3), PARPi (AZD2281-olaparib and ABT-888-veliparib) had limited single-agent efficacy (IC₅₀ > 10 μmol/L) in proliferation assays. Despite limited single-agent efficacy, submicromolar concentrations of AZD2281 in combination with RT led to significant radiosensitization (rER 1.12-1.76). This effect was partially dependent on BRCA1 mutational status. Radiosensitization was due, at least in part, to delayed resolution of double strand DNA breaks as measured by multiple assays. Using a SUM-190 xenograft model in vivo, the combination of PARPi and RT significantly delays tumor doubling and tripling times compared with PARPi or RT alone with limited toxicity. This study demonstrates that PARPi improves the effectiveness of radiotherapy in IBC models and provides the preclinical rationale for the opening phase II randomized trial of RT ± PARPi in women with IBC (SWOG 1706, NCT03598257).

Primary tumor resection for initially staged IV breast cancer: An emphasis on programmed death-ligand 1 expression, promoter methylation status, and survival

Conventional therapy modalities for advanced breast cancer are problematic, whereas checkpoint blockade immunotherapy has been considered as a promising approach. This study aims to determine programmed death-ligand 1 (PD-L1) expression and methylation status of PD-L1 promoter in primary tumor tissue and metastatic foci of patients with stage IV breast cancer.Clinicopathological data and survival rates of 57 breast cancer patients, who were initially staged IV, and operated for intact tumors, were retrospectively analyzed. Immunohistochemical analysis of PD-L1 using 57 primary tumors, 33 paired metastatic lymph nodes, and 14 paired distant metastases was performed. Additionally, the methylation rate of the PD-L1 gene promoter region was determined with real-time polymerase chain reaction (PCR) analysis in 38 samples.Overall PD-L1 expression in primary tumors was 23.1% (12/52). PD-L1 positivity was reduced in lymph nodes by 15.2% (5/33) and in distant metastases by 21.4% (3/14). PD-L1 expression diverged between primary and metastatic foci in a subset of cases (18.2% for lymph node and 33.3% for distant metastasis). In general, the PD-L1 promoter was not methylated, and mean methylation rates were low (min. 0%-max. 21%). We observed no correlation between PD-L1 expression, promoter methylation, and survival.Neither the expression nor the methylation status of PD-L1 in patients, who were presented with stage IV breast cancer and operated for an intact primary tumor, had a statistically significant relation with survival. Discordance in PD-L1 expression between primary tumor and metastasis should be considered during pathological and clinical management of patients who would undergo checkpoint blockade therapy.

Perspectives on Inflammatory Breast Cancer (IBC) Research, Clinical Management and Community Engagement from the Duke IBC Consortium

Inflammatory breast cancer (IBC) is an understudied and aggressive form of breast cancer with a poor prognosis, accounting for 2-6% of new breast cancer diagnoses but 10% of all breast cancer-related deaths in the United States. Currently there are no therapeutic regimens developed specifically for IBC, and it is critical to recognize that all aspects of treating IBC - including staging, diagnosis, and therapy - are vastly different than other breast cancers. In December 2014, under the umbrella of an interdisciplinary initiative supported by the Duke School of Medicine, researchers, clinicians, research administrators, and patient advocates formed the Duke Consortium for IBC to address the needs of patients in North Carolina (an ethnically and economically diverse state with 100 counties) and across the Southeastern United States. The primary goal of this group is to translate research into action and improve both awareness and patient care through collaborations with local, national and international IBC programs. The consortium held its inaugural meeting on Feb 28, 2018, which also marked Rare Disease Day and convened national research experts, clinicians, patients, advocates, government representatives, foundation leaders, staff, and trainees. The meeting focused on new developments and challenges in the clinical management of IBC, research challenges and opportunities, and an interactive session to garner input from patients, advocates, and community partners that would inform a strategic plan toward continuing improvements in IBC patient care, research, and education.

Immunotherapy in breast cancer

The idea of using the immune system to fight cancer is over 100 years old. A new molecular approach led to a better understanding of the immune system. Checkpoint regulation, understanding the roles of Tregs, Th1, and Th2, development of Chimeric antigen receptor (CAR)-T cells, as well as regulation of dendritic cells and macrophages, are just a few examples of our understating that has also led to the discovery of immune checkpoint inhibitors (ICIs) and modulators. This led the Nobel Prize committee in 2018, to award Dr. James P. Allison the Nobel Prize in medicine for the discovery of Cytotoxic T-lymphocyte-associated antigen-4, and Dr. Tasuku Honjo for the discovery of programmed cell death-1 (PD-1)/PD-1-ligand (PDL-1). Several ICIs are already approved by the regulatory authorities, and many more are currently used in studies of several solid tumors and hematologic malignancies. Positive studies have led to the US Food and Drug Administration (FDA) and European Medicines Agency approval of a number of these compounds, but none to date are approved in breast cancer (BC). Moreover, PD-1/PDL-1, MSI high (and dMMR), and tumor mutational burden are the currently “best” predictive markers for benefit from immunotherapy. BCs have some of these markers positive only in subsets but less frequently expressed than most other solid tumors, for example, malignant melanoma or non-small cell lung cancer. To improve the potential efficacy of ICI in BC, the addition of chemotherapy was one of the strategies. Many early and large clinical trials in all phases are underway in BC. We will discuss the role of immune system in BC editing, and the potential impact of immunotherapy in BC outcomes.