Identification of the Tumor Infiltrating Lymphocytes (TILs) Landscape in Pure Squamous Cell Carcinoma of the Bladder

Background: Tumor infiltrating lymphocytes (TILs) are known as important prognostic biomarkers and build the fundament for immunotherapy. However, the presence of TILs and its impact on outcome in pure squamous cell carcinoma (SCC) of the bladder remains uncertain. Methods: Out of 1600 patients undergoing radical cystectomy, 61 patients revealed pure bladder SCC in the final histopathological specimen. Retrospectively, immunohistochemical staining was performed on a subset of TILs (CD3+, CD4+, CD8+, CD20+). Endpoints were overall survival (OS), cancer-specific survival (CSS) and progression-free survival (PFS). The Kaplan−Meier method was used to evaluate survival outcomes. Results: Strong infiltration of CD3+ was found in 27 (44%); of CD4+ in 28 (46%); of CD8+ in 26 (43%); and of CD20+ in 27 tumors (44%). Improved OS was observed for strong CD3+ (p < 0.001); CD4+ (p = 0.045); CD8+ (p = 0.001); and CD20+ infiltration (p < 0.001). Increased rates of PFS were observed for CD3+ (p = 0.025) and CD20+ TILs (p = 0.002). In multivariate analyses, strong CD3+ (HR: 0.163, CI: 0.044−0.614) and strong CD8+ TILs (HR: 0.265, CI: 0.081−0.864) were revealed as predictors for OS and the strong infiltration of CD20+ cells (HR: 0.095, CI: 0.019−0.464) for PFS. Conclusions: These first results of TILs in bladder SCC revealed predictive values of CD3+, CD8+ and CD20+.

The prognostic value of stromal tumor-infiltrating lymphocytes in intrahepatic cholangiocarcinoma: a population-based study

OBJECTIVE

We assess the predictive value impacted by tumor-infiltrating lymphocytes (TILs) for overall survival (OS) and progression-free survival (PFS) in patients with intrahepatic cholangiocarcinoma (ICC) undergoing complete resection.

METHODS

Sixty-eight patients with resectable ICC were included in this study. We studied stromal TIL density and scored it by staining sections from surgically resected ICC patients with hematoxylin and eosin (HE). The clinical data and prognosis of patients with ICC were obtained by searching clinical and follow-up records.

RESULTS

A stromal TIL negative status was a predictor of poor OS (HR = 0.41, 95% CI 0.20-0.83, p = .01) and poor PFS (HR = 0.47, 95% CI 0.23-0.97, p = .04) independently. Low stromal TIL density was associated with high levels of CA125 (p = .03) and CA19-9 (p < .01). The high level of CA19-9 (p = .05), high differentiation (p = .02), a large diameter (p = .05), a positive bile duct/vascular cancer embolus (p = .03) and positive satellite nodules (p = .02) were tendencies to develop tumors for patients with a negative status of stromal TIL.

CONCLUSION

Our data prompt for the prediction of the PFS and OS of patients with ICC after complete resection, stromal TILs play an important role.

Tumor-infiltrating lymphocytes in early breast cancer: an exploratory analysis focused on HER2+ subtype in Portuguese patients

Tumor-infiltrating lymphocytes (TILs) have shown prognostic value in breast cancer. This study evaluated the TILs scores in 186 Portuguese patients diagnosed with early breast cancer, with special focus on HER2 subtype. Stromal TILs were scored on the core needle biopsies, as well as in the resected specimen in HER2+ patients submitted to neoadjuvant treatment with trastuzumab and pertuzumab. TILs were higher in tumors with negative hormone receptor status and HER2 amplifications, and in triple-negative breast cancer. In HER2+ patients treated with dual anti-HER neoadjuvant therapy, the TILs score on the surgical specimen was generally lower than in the biopsy.

Prosaposin, tumor-secreted protein, promotes pancreatic cancer progression by decreasing tumor-infiltrating lymphocytes

Glycoproteins produced by tumor cells are involved in cancer progression, metastasis, and the immune response, and serve as possible therapeutic targets. Considering the dismal outcomes of pancreatic ductal adenocarcinoma (PDAC) due to its unique tumor microenvironment, which is characterized by low antitumor T-cell infiltration, we hypothesized that tumor-derived glycoproteins may serve as regulating the tumor microenvironment. We used glycoproteomics with tandem mass tag labeling to investigate the culture media of three human PDAC cell lines, and attempted to identify the key secreted proteins from PDAC cells. Among the identified glycoproteins, prosaposin (PSAP) was investigated for its functional contribution to PDAC progression. PSAP is highly expressed in various PDAC cell lines; however, knockdown of intrinsic PSAP expression did not affect the proliferation and migration capacities. Based on the immunohistochemistry of resected human PDAC tissues, high PSAP expression was associated with poor prognosis in patients with PDAC. Notably, tumors with high PSAP expression showed significantly lower CD8+ T-cell infiltration than those with low PSAP expression. Furthermore, PSAP stimulation decreased the proportion of CD8+ T cells in peripheral blood monocytes. Finally, in an orthotopic transplantation model, the number of CD8+ T cells in the PSAP shRNA groups was significantly increased, resulting in a decreased tumor volume compared with that in the control shRNA group. PSAP suppresses CD8+ T-cell infiltration, leading to the promotion of PDAC progression. However, further studies are warranted to determine whether this study contributes to the development of a novel immunomodulating therapy for PDAC.

Relationship between consolidation tumor ratio and tumor-infiltrating lymphocytes in small-sized lung adenocarcinoma

Background

Consolidation tumor ratio (CTR) is associated with cancer progression and histological invasiveness in lung adenocarcinoma (LAD). However, little is known about the association between CTR and immune‐related factors, including tumor‐infiltrating lymphocytes (TILs) density or tumor expression of programmed death ligand 1 (PD‐L1) and indoleamine 2,3‐dioxygenase 1 (IDO1) in small‐sized LAD.

Methods

This study included 258 patients with LAD (<3 cm) who underwent surgery. Patients were assigned to four groups: CTR = 0; 0 < CTR <0.5; 0.5 ≤ CTR <1 (ground‐glass opacity [GGO] group); and CTR = 1 (pure‐solid group). CD4⁺, CD8⁺, and FoxP3⁺ TIL density and PD‐L1 and IDO1 tumor expression were assessed by immunohistochemistry.

Results

Among the GGO group, CD8⁺ and FoxP3⁺ TIL density increased significantly with increasing CTR (p < 0.001 and p < 0.001, respectively). Moreover, PD‐L1 and IDO1 expression was significantly higher in the pure‐solid group than in the GGO group (p < 0.001 and p < 0.001, respectively).

Conclusions

CTR was correlated with the abundance of CD8⁺ and FoxP3⁺ TILs in the GGO group. PD‐L1 and IDO1 positivity rates were significantly higher in the pure‐solid group than in the GGO group. Increased CTR may be correlated with immunosuppressive condition.

Immune Cell and Biochemical Biomarkers in Advanced Laryngeal Cancer

Objective

The aim of this study was to evaluate cell and biochemical biomarkers and establish their prognostic value in patients with advanced laryngeal cancer.

Material and Methods

A prospective study included 52 patients with advanced laryngeal carcinoma surgically treated at the tertiary referral center. Tumor tissue was immunohistochemically stained for T-cell markers (CD4 and CD8), and levels of cytokines (IL-6 and IL-8) and C-reactive protein were analyzed from blood samples.

Results

Overall 3-year survival (OS) of patients included in the study was 69.2% and the disease specific survival (DSS) 72.5%. Higher expression of CD4⁺ and CD8⁺ were significant prognostic factors with positive impact on both OS and DSS in univariate analysis, but not in multivariate analysis. Levels of IL-8 were a significant predictor of 3-year OS and DSS survival in patients with advanced laryngeal cancer but not levels of IL-6 and CRP values.

Conclusion

Though high expression of CD4 and CD8 were demonstrated in the tumor tissue, but their prognostic role was not established. Higher values of IL-8 proved to be significant negative predictor of DSS. This could further collaborate the inclusion of combination of biomarkers in assessment of favorable treatment choice in patients with advanced laryngeal carcinoma.

Validation of the Optimum Timing of Assessment of Tumor Infiltrating Lymphocytes During Preoperative Chemotherapy for Breast Cancer

BACKGROUND/AIM

Tumor microenvironment (TME) assessment is considered to play an important role in the prediction of prognosis and therapeutic response following breast cancer treatment. No consensus has been reached regarding evaluation methods despite reports on the utilization of tumor-infiltrating lymphocytes (TILs) for immune TME (iTME) monitoring. Optimum timing of iTME assessment has not yet been established.

PATIENTS AND METHODS

Two hundred thirty-nine patients were treated with neoadjuvant chemotherapy (NAC). During the period from diagnostic needle biopsy to NAC initiation for breast cancer, the optimal evaluation timing was examined using a receiver operating characteristic (ROC) curve analysis.

RESULTS

A significant correlation between TILs and pathological complete response (pCR) was only observed in the short-term group (≤35 days) (p=0.033). Prognostic analysis revealed that in the short-term group, patients with high TIL levels had a significantly better survival prognosis relative to those with low TIL levels (>35 days) [disease-free survival (DFS): p=0.001, overall survival (OS): p=0.021]. TILs were identified as an independent factor affecting DFS in a multivariate analysis (p=0.008, hazard ratio=0.130).

CONCLUSION

TIL assessment during NAC for breast cancer is a prognostic predictor only when performed at ≤35 days before NAC initiation.

Spatial analysis of tumor-infiltrating lymphocytes in histological sections using deep learning techniques predicts survival in colorectal carcinoma

This study aimed to explore the prognostic impact of spatial distribution of tumor‐infiltrating lymphocytes (TILs) quantified by deep learning (DL) approaches based on digitalized whole‐slide images stained with hematoxylin and eosin in patients with colorectal cancer (CRC). The prognostic impact of spatial distributions of TILs in patients with CRC was explored in the Yonsei cohort (n = 180) and validated in The Cancer Genome Atlas (TCGA) cohort (n = 268). Two experienced pathologists manually measured TILs at the most invasive margin (IM) as 0–3 by the Klintrup–Mäkinen (KM) grading method and this was compared to DL approaches. Inter‐rater agreement for TILs was measured using Cohen's kappa coefficient. On multivariate analysis of spatial TIL features derived by DL approaches and clinicopathological variables including tumor stage, microsatellite instability, and KRAS mutation, TIL densities within 200 μm of the IM (f_im200) remained the most significant prognostic factor for progression‐free survival (PFS) (hazard ratio [HR] 0.004 [95% confidence interval, CI, 0.0001–0.15], p = 0.0028) in the Yonsei cohort. On multivariate analysis using the TCGA dataset, f_im200 retained prognostic significance for PFS (HR 0.031 [95% CI 0.001–0.645], p = 0.024). Inter‐rater agreement of manual KM grading was insignificant in the Yonsei (κ = 0.109) and the TCGA (κ = 0.121) cohorts. The survival analysis based on KM grading showed statistically significant different PFS in the TCGA cohort, but not the Yonsei cohort. Automatic quantification of TILs at the IM based on DL approaches shows prognostic utility to predict PFS, and could provide robust and reproducible TIL density measurement in patients with CRC.

Prognostic Significance of NLR, PLR, LMR and Tumor Infiltrating T Lymphocytes in Patients Undergoing Surgical Resection for Hilar Cholangiocarcinoma

Objective

This study evaluated the prognostic significance of preoperative neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), lymphocyte to monocyte ratio (LMR) and tumor-infiltrating lymphocytes (TILs), and whether these preoperative blood inflammatory indicators were associated with TILs in hilar cholangiocarcinoma (HCCA).

Methods

A total of 76 patients with HCCA who underwent radical resection were included. Data on their clinicopathologic characteristics, perioperative features, and survival outcomes were analyzed. The optimal cutoff levels for the NLR, PLR and LMR were defined by using the web application Cut-off Finder. The densities of specific immune cells (CD3⁺, CD4⁺, CD8⁺) within the tumor microenvironment were examined by immunohistochemical. The association of the number of CD3⁺, CD4⁺ and CD8⁺ T cells infiltration in the local tumor microenvironment with preoperative NLR, PLR and LMR level was analyzed. Survival curves were calculated using the Kaplan-Meier estimate. Univariate and multivariate logistic regression models were used to identify factors associated with overall survival.

Results

The optimal cutoff value of preoperative NLR, PLR and LMR was 2.00, 117.60, and 4.02, respectively. NLR was significantly negatively correlated with CD3⁺ and CD8⁺ T cell infiltration, but not with CD4⁺ T cells. PLR had no correlation with CD3⁺, CD4⁺, or CD8⁺ T cell infiltration, while LMR had a significantly positive correlation with CD3⁺ T cells infiltration but not with CD4⁺ or CD8⁺ T cells. In the multivariate logistic regression model, T stage, lymph node metastasis, CA19-9 and LMR were independent risk factors associated with overall survival (OS). Survival curves indicated that HCCA patients with low CD3⁺ T cells infiltration and low preoperative LMR live shorter than others.

Conclusions

LMR played as an independent factor for predicting the survival in patients with HCCA after R0 radical resection. A high LMR was associated with an accumulation of CD3⁺ T cells in HCCA.

Spontaneous xenogeneic GvHD in Wilms' tumor Patient-Derived xenograft models and potential solutions

Severely immunocompromised NOD.Cg-Prkdc^scid Il2rg^tm1Sug (NOG) mice are among the ideal animal recipients for generation of human cancer models. Transplantation of human solid tumors having abundant tumor-infiltrating lymphocytes (TILs) can induce xenogeneic graft-versus-host disease (xGvHD) following engraftment and expansion of the TILs inside the animal body. Wilms' tumor (WT) has not been recognized as a lymphocyte-predominant tumor. However, 3 consecutive generations of NOG mice bearing WT patient-derived xenografts (PDX) xenotransplanted from a single donor showed different degrees of inflammatory symptoms after transplantation before any therapeutic intervention. In the initial generation, dermatitis, auto-amputation of digits, weight loss, lymphadenopathy, hepatitis, and interstitial pneumonitis were observed. Despite antibiotic treatment, no response was noticed, and thus the animals were prematurely euthanized (day 47 posttransplantation). Laboratory and histopathologic evaluations revealed lymphoid infiltrates positively immunostained with anti-human CD3 and CD8 antibodies in the xenografts and primary tumor, whereas no microbial infection or lymphoproliferative disorder was found. Mice of the next generation that lived longer (91 days) developed sclerotic skin changes and more severe pneumonitis. Cutaneous symptoms were milder in the last generation. The xenografts of the last 2 generations also contained TILs, and lacked lymphoproliferative transformation. The systemic immunoinflammatory syndrome in the absence of microbial infection and posttransplant lymphoproliferative disorder was suggestive of xGvHD. While there are few reports of xGvHD in severely immunodeficient mice xenotransplanted from lymphodominant tumor xenografts, this report for the first time documented serial xGvHD in consecutive passages of WT PDX-bearing models and discussed potential solutions to prevent such an undesired complication.

A Pragmatic Machine Learning Approach to Quantify Tumor-Infiltrating Lymphocytes in Whole Slide Images

Simple Summary

Tumor tissues sampled from patients contain prognostic and predictive information beyond what is currently being used in clinical practice. Large-scale digitization enables new ways of exploiting this information. The most promising analysis pipelines include deep learning/artificial intelligence (AI). However, to ensure success, AI often requires a time-consuming curation of data. In our approach, we repurposed AI pipelines and training data for cell segmentation and classification to identify tissue-infiltrating lymphocytes (TILs) in lung cancer tissue. We showed that our approach is able to identify TILs and provide prognostic information in an unseen dataset from lung cancer patients. Our methods can be adapted in myriad ways and may help pave the way for the large-scale deployment of digital pathology.

Abstract

Increased levels of tumor-infiltrating lymphocytes (TILs) indicate favorable outcomes in many types of cancer. The manual quantification of immune cells is inaccurate and time-consuming for pathologists. Our aim is to leverage a computational solution to automatically quantify TILs in standard diagnostic hematoxylin and eosin-stained sections (H&E slides) from lung cancer patients. Our approach is to transfer an open-source machine learning method for the segmentation and classification of nuclei in H&E slides trained on public data to TIL quantification without manual labeling of the data. Our results show that the resulting TIL quantification correlates to the patient prognosis and compares favorably to the current state-of-the-art method for immune cell detection in non-small cell lung cancer (current standard CD8 cells in DAB-stained TMAs HR 0.34, 95% CI 0.17–0.68 vs. TILs in HE WSIs: HoVer-Net PanNuke Aug Model HR 0.30, 95% CI 0.15–0.60 and HoVer-Net MoNuSAC Aug model HR 0.27, 95% CI 0.14–0.53). Our approach bridges the gap between machine learning research, translational clinical research and clinical implementation. However, further validation is warranted before implementation in a clinical setting.

Prognostic and Predictive Relevance of Tumor-Infiltrating Lymphocytes in Squamous Cell Head-Neck Cancer Patients Treated with Radical Radiotherapy/Chemo-Radiotherapy

Microenvironmental conditions control the entrance and thriving of cytotoxic lymphocytes in tumors, allowing or preventing immune-mediated cancer cell death. We investigated the role of tumor-infiltrating lymphocyte (TIL) density in the outcome of radiotherapy in a series of squamous cell head−neck tumors (HNSCC). Moreover, we assessed the link between markers of hypoxia and TIL density. One-hundred twenty-one patients with HNSCC treated prospectively with radical radiotherapy/chemo-radiotherapy were analyzed. The assessment of TIL density was performed on hematoxylin and eosin biopsy sections before radiotherapy. TIL density ranged from 0.8 to 150 lymphocytes per ×40 optical field (median 27.5). Using the median value, patients were grouped into two categories of low and high TIL density. Early T-stage tumors had a significantly higher TIL density (p < 0.003), but we found no association with N-stage. Overexpression of HIF1α, HIF2α, and CA9 was significantly linked with poor infiltration by TILs (p < 0.03). A significant association of high TIL density with better disease-specific overall survival and improved locoregional relapse-free survival was noted (p = 0.008 and 0.02, respectively), which was also confirmed in multivariate analysis. It is concluded that HNSCC phenotypes that allow for the intratumoral accumulation of lymphocytes have a better outcome following radical radiotherapy/chemo-radiotherapy. Intratumoral-activated HIF- and CA9-related pathways characterize immunologically cold tumors and may be used as targets for therapeutic interventions.

A Fraction of CD8+ T Cells from Colorectal Liver Metastases Preferentially Repopulate Autologous Patient-Derived Xenograft Tumors as Tissue-Resident Memory T Cells

The diversity of T cells in the human liver may reflect the composition of TILs in CRLM. Our ex vivo characterization of CRLM vs. adjacent liver tissue detected CD103+CD39+CD8+ T_RM cells predominantly in CRLM, which prompted further assessments. These T_RM cells responded to cognate antigens in vitro. As functional activities of autologous TILs are central to the implementation of personalized cancer treatments, we applied a patient-derived xenograft (PDX) model to monitor TILs' capacity to control CRLM-derived tumors in vivo. We established PDX mice with CRLMs from two patients, and in vitro expansion of their respective TILs resulted in opposing CD4+ vs. CD8+ TIL ratios. These CRLMs also displayed mutated KRAS, which enabled trametinib-mediated inhibition of MEK. Regardless of the TIL subset ratio, persistent or transient control of CRLM-derived tumors of limited size by the transferred TILs was observed only after trametinib treatment. Of note, a portion of transferred TILs was observed as CD103+CD8+ T_RM cells that strictly accumulated within the autologous CRLM-derived tumor rather than in the spleen or blood. Thus, the predominance of CD103+CD39+CD8+ T_RM cells in CRLM relative to the adjacent liver and the propensity of CD103+CD8+ T_RM cells to repopulate the autologous tumor may identify these TILs as strategic targets for therapies against advanced CRC.

Immunology and immunotherapy in breast cancer

Immuno-oncology is a rapidly developing field in medicine. Drug combination therapies have already been studied in many clinical trials on various tumor types. In recent years, a checkpoint inhibition therapy with monoclonal antibodies targeting PD-1 and its ligand PD-L1 has been developed. Breast cancer had been examined in the field of immune-oncology relatively recently. This review focuses on clinical evidence regarding immune checkpoint inhibition for curative treatment of various breast cancer subtypes. In addition, we present the results of studies demonstrating the prognostic and predictive value of levels of tumorinfiltrating lymphocytes (CD4 and CD8), their quantitative ratios, and their correlation with regulatory genes (PD-1, PD-L1, and FOX-P3).

Prognostic Significance of Lymphocyte Infiltrate Localization in Triple-Negative Breast Cancer

High infiltration by tumor-infiltrating lymphocytes (TILs) is associated with favorable prognosis in different tumor types, but the clinical significance of their spatial localization within the tumor microenvironment is debated. To address this issue, we evaluated the accumulation of intratumoral TILs (itTILs) and stromal TILs (sTILs) in samples from 97 patients with early triple-negative breast cancer (TNBC) in the center (sTIL central) and periphery (sTIL peripheral) of tumor tissues. Moreover, the presence of primary and secondary lymphoid aggregates (LAs) and the expression levels of the cancer testis antigen (CTA), NY-ESO-1, and PD-L1 were explored. High infiltration by itTILs was observed in 12/97 samples (12.3%), unrelated to age, Ki67 expression, tumor size, histologic type and grade, and LA presence. NY-ESO-1 was expressed in tumor cells in 37 samples (38%), with a trend suggesting a correlation with itTIL infiltration (p = 0.0531). PD-L1 expression was detected in immune cells in 47 samples (49%) and was correlated with histologic grade, sTILs, and LA formation. The presence of primary LAs was significantly correlated with better disease-free survival (DFS) (p = 0.027). Moreover, no tumor progression was observed during >40 months of clinical follow up in the 12 patients with high itTILs or in the 14 patients with secondary LAs. Thus, careful evaluation of lymphoid infiltrate intratumoral localization might provide important prognostic information.

Poorer survival outcomes in patients with multiple versus single primary melanoma

BACKGROUND

Given equivocal results related to overall survival (OS) for patients with multiple primary melanomas (MPMs) compared with those with single primary melanomas (SPMs) in previous reports, the authors sought to determine whether OS differs between these 2 cohorts in their center using their UPCI-96-99 database. Secondary aims were to assess the differences in recurrence-free survival (RFS). In a subset of patients, transcriptomic profiling of peripheral blood mononuclear cells (PBMCs) was performed to assess disease-associated genes of interest.

METHODS

This retrospective case-controlled study included patients with MPMs and age-, sex-, and stage-matched controls with SPMs at a 1:1 ratio. Cox regression models were used to evaluate the effect of the presence of MPMs on death and recurrence. NanoString PanCancer Immune Profiling was used to assess peripheral blood immune status in patients.

RESULTS

In total, 320 patients were evaluated. The mean patient age was 47 years; 43.8% were male. Patients with MPMs had worse RFS and OS (P = .023 and P = .0019, respectively). The presence of MPMs was associated with an increased risk of death (hazard ratio [HR], 4.52, P = .0006), and increased risk of disease recurrence (HR, 2.17; P = .004) after adjusting for age, sex, and stage. The degree of tumor-infiltrating lymphocytes (TILs) was different between the first melanoma of MPMs and SPMs. Expression of CXCL6 and FOXJ1 was increased in PBMCs isolated from patients with MPMs.

CONCLUSIONS

Patients with MPMs had worse RFS and OS compared with patients with SPMs. Immunologic differences were also observed, including TIL content and expression of CXCL6/FOXJ1 in PBMCs of patients with MPMs, which warrant further investigation.

Building Efficient CNN Architectures for Histopathology Images Analysis: A Case-Study in Tumor-Infiltrating Lymphocytes Classification

Background

Deep learning methods have demonstrated remarkable performance in pathology image analysis, but they are computationally very demanding. The aim of our study is to reduce their computational cost to enable their use with large tissue image datasets.

Methods

We propose a method called Network Auto-Reduction (NAR) that simplifies a Convolutional Neural Network (CNN) by reducing the network to minimize the computational cost of doing a prediction. NAR performs a compound scaling in which the width, depth, and resolution dimensions of the network are reduced together to maintain a balance among them in the resulting simplified network. We compare our method with a state-of-the-art solution called ResRep. The evaluation is carried out with popular CNN architectures and a real-world application that identifies distributions of tumor-infiltrating lymphocytes in tissue images.

Results

The experimental results show that both ResRep and NAR are able to generate simplified, more efficient versions of ResNet50 V2. The simplified versions by ResRep and NAR require 1.32× and 3.26× fewer floating-point operations (FLOPs), respectively, than the original network without a loss in classification power as measured by the Area under the Curve (AUC) metric. When applied to a deeper and more computationally expensive network, Inception V4, NAR is able to generate a version that requires 4× lower than the original version with the same AUC performance.

Conclusions

NAR is able to achieve substantial reductions in the execution cost of two popular CNN architectures, while resulting in small or no loss in model accuracy. Such cost savings can significantly improve the use of deep learning methods in digital pathology. They can enable studies with larger tissue image datasets and facilitate the use of less expensive and more accessible graphics processing units (GPUs), thus reducing the computing costs of a study.

Development of Training Materials for Pathologists to Provide Machine Learning Validation Data of Tumor-Infiltrating Lymphocytes in Breast Cancer

Simple Summary

The High Throughput Truthing project aims to develop a dataset of stromal tumor-infiltrating lymphocytes (sTILs) density evaluations in hematoxylin and eosin-stained invasive breast cancer specimens fit for a regulatory purpose. After completion of the pilot study, the analysis demonstrated inconsistencies and gaps in the provided training to pathologists. Select regions of interest (ROIs) were reviewed by an expert panel, who provided annotations and commentary on the challenges of the sTILs assessment. We used these annotations to develop a training document and reference standard for new training materials. These materials will train crowd-sourced pathologists to help create an algorithm validation dataset and contribute to sTILs evaluations in clinical practice.

Abstract

The High Throughput Truthing project aims to develop a dataset for validating artificial intelligence and machine learning models (AI/ML) fit for regulatory purposes. The context of this AI/ML validation dataset is the reporting of stromal tumor-infiltrating lymphocytes (sTILs) density evaluations in hematoxylin and eosin-stained invasive breast cancer biopsy specimens. After completing the pilot study, we found notable variability in the sTILs estimates as well as inconsistencies and gaps in the provided training to pathologists. Using the pilot study data and an expert panel, we created custom training materials to improve pathologist annotation quality for the pivotal study. We categorized regions of interest (ROIs) based on their mean sTILs density and selected ROIs with the highest and lowest sTILs variability. In a series of eight one-hour sessions, the expert panel reviewed each ROI and provided verbal density estimates and comments on features that confounded the sTILs evaluation. We aggregated and shaped the comments to identify pitfalls and instructions to improve our training materials. From these selected ROIs, we created a training set and proficiency test set to improve pathologist training with the goal to improve data collection for the pivotal study. We are not exploring AI/ML performance in this paper. Instead, we are creating materials that will train crowd-sourced pathologists to be the reference standard in a pivotal study to create an AI/ML model validation dataset. The issues discussed here are also important for clinicians to understand about the evaluation of sTILs in clinical practice and can provide insight to developers of AI/ML models.

AHCC®, a Standardized Extract of Cultured Lentinula Edodes Mycelia, Promotes the Anti-Tumor Effect of Dual Immune Checkpoint Blockade Effect in Murine Colon Cancer

Treatment strategies combining immune checkpoint blockade (ICB) with other agents have emerged as a promising approach in the treatment of cancers. AHCC^®, a standardized extract of cultured Lentinula edodes mycelia, has been reported to inhibit tumor growth and enhance immune cell function. Here we investigated whether AHCC^® promotes the therapeutic effect of immunotherapy in cancers. A combination of oral AHCC^® and dual immune checkpoint blockade (DICB), including PD-1/CTLA-4 blockade, had reduced tumor growth and increased granzyme B and Ki-67 expression by tumor-infiltrating CD8⁺ T cells in MC38 colon cancer bearing mice compared to a combination of water and DICB. In the same tumor bearing mice, AHCC^® and DICB treatment also altered the composition of the gut microbiome with the increased abundance of the species of Ruminococcaceae family which is associated with increased therapeutic efficacy of immunotherapy. The anti-tumor effect of AHCC^® and DICB was not found in MC38 tumor-bearing mice treated with antibiotics. These data suggest that AHCC^® increases the anti-tumor effect of DICB by enhancing T cell function and affecting the gut microbiome.

An activation to memory differentiation trajectory of tumor-infiltrating lymphocytes informs metastatic melanoma outcomes

There is a need for better classification and understanding of tumor-infiltrating lymphocytes (TILs). Here, we applied advanced functional genomics to interrogate 9,000 human tumors and multiple single-cell sequencing sets using benchmarked T cell states, comprehensive T cell differentiation trajectories, human and mouse vaccine responses, and other human TILs. Compared with other T cell states, enrichment of T memory/resident memory programs was observed across solid tumors. Trajectory analysis of single-cell melanoma CD8+ TILs also identified a high fraction of memory/resident memory-scoring TILs in anti-PD-1 responders, which expanded post therapy. In contrast, TILs scoring highly for early T cell activation, but not exhaustion, associated with non-response. Late/persistent, but not early activation signatures, prognosticate melanoma survival, and co-express with dendritic cell and IFN-γ response programs. These data identify an activation-like state associated to poor response and suggest successful memory conversion, above resuscitation of exhaustion, is an under-appreciated aspect of successful anti-tumoral immunity.

A phenotypic signature that identifies neoantigen-reactive T cells in fresh human lung cancers

A common theme across multiple successful immunotherapies for cancer is the recognition of tumor-specific mutations (neoantigens) by T cells. The rapid discovery of such antigen responses could lead to improved therapies through the adoptive transfer of T cells engineered to express neoantigen-reactive T cell receptors (TCRs). Here, through CITE-seq (cellular indexing of transcriptomes and epitopes by sequencing) and TCR-seq of non-small cell lung cancer (NSCLC) tumor-infiltrating lymphocytes (TILs), we develop a neoantigen-reactive T cell signature based on clonotype frequency and CD39 protein and CXCL13 mRNA expression. Screening of TCRs selected by the signature allows us to identify neoantigen-reactive TCRs with a success rate of 45% for CD8+ and 66% for CD4+ T cells. Because of the small number of samples analyzed (4 patients), generalizability remains to be tested. However, this approach can enable the quick identification of neoantigen-reactive TCRs and expedite the engineering of personalized neoantigen-reactive T cells for therapy.

Neoadjuvant chemoradiation alters the immune microenvironment in pancreatic ductal adenocarcinoma

Patients with pancreatic ductal adenocarcinoma (PDAC) have a grim prognosis despite complete surgical resection and intense systemic therapies. While immunotherapies have been beneficial with many different types of solid tumors, they have almost uniformly failed in the treatment of PDAC. Understanding how therapies affect the tumor immune microenvironment (TIME) can provide insights for the development of strategies to treat PDAC. We used quantitative multiplexed immunofluorescence (qmIF) quantitative spatial analysis (qSA), and immunogenomic (IG) analysis to analyze formalin-fixed paraffin embedded (FFPE) primary tumor specimens from 44 patients with PDAC including 18 treated with neoadjuvant chemoradiation (CRT) and 26 patients receiving no treatment (NT) and compared them with tissues from 40 treatment-naïve melanoma patients. We find that relative to NT tumors, CD3+ T cell infiltration was increased in CRT treated tumors (p = .0006), including increases in CD3+CD8+ cytotoxic T cells (CTLs, p = .0079), CD3+CD4+FOXP3- T helper cells (Th, p = .0010), and CD3+CD4+FOXP3+ regulatory T cells (Tregs, p = .0089) with no difference in CD68+ macrophages. IG analysis from micro-dissected tissues indicated overexpression of genes involved in antigen presentation, T cell activation, and inflammation in CRT treated tumors. Among treated patients, a higher ratio of Tregs to total T cells was associated with shorter survival time (p = .0121). Despite comparable levels of infiltrating T cells in CRT PDACs to melanoma, PDACs displayed distinct spatial profiles with less T cell clustering as defined by nearest neighbor analysis (p < .001). These findings demonstrate that, while CRT can achieve high T cell densities in PDAC compared to melanoma, phenotype and spatial organization of T cells may limit benefit of T cell infiltration in this immunotherapy-resistant tumor.

Tumor-infiltrating ICOS+ Effector Regulatory T-Cells in Oral Squamous Cell Carcinoma as a Promising Biomarker for Prognosis and 'Hot' Tumor

BACKGROUND

Tumor immunity in the tumor microenvironment is activated in patients with feasible clinical responses to immune checkpoint inhibitors. The immunological profile of tumor-infiltrating lymphocytes (TILs) obtained from patients with oral squamous cell carcinoma (OSCC) was examined in relation to their prognosis.

MATERIALS AND METHODS

Surface antigens, including immune checkpoint molecules, on TILs from 31 patients with primary OSCC were analyzed by flow cytometry. The activation status of TILs was examined through a heatmap analysis and unsupervised clustering classified patients into groups with activated or inactivated TILs. A supervised machine-learning algorithm for single-cell analyses in relation to prognosis was run using the Cluster Identification, Characterization, and Regression (CITRUS) program.

RESULTS

None of surface antigens were related to prognosis. The CITRUS program revealed a relationship between CD45RA^-CD4⁺ CD25^high inducible T-cell co-stimulator (ICOS)⁺ TILs and recurrence, and also identified a similar fraction significantly specific to the group with activated TILs. The disease-free survival rate for patients with ≥95% ICOS⁺ TILs was significantly lower than that for those with <95% ICOS⁺ TILs. Furthermore, a review of clinicopathological factors related to prognosis identified the percentage of ICOS⁺ TILs to be an independent prognostic factor for patients with OSCC.

CONCLUSION

CD25^highICOS⁺ regulatory T-cells in TILs have potential as a biomarker for predicting recurrence after surgical treatment and clinical responses to immune checkpoint inhibitors in patients with OSCC.

Human Papillomavirus, Cytomegalovirus Infection and P16 Staining in Breast Tumors from Peruvian Women

Objective:

To evaluate the frequency distribution of viral infections in Peruvian Breast Cancer (BC) lesions and its association with clinicopathological features. Additionally, a prospective evaluation of p16 and Tumor-infiltrating lymphocytes (TIL) levels were performed for developing a comprehensive analysis.

Methods:

Detection of high risk- human papillomavirus (HR- HPV) through qPCR was performed in 447 BC and 79 non-cancer frozen samples. Paired paraffin samples from 238 BC were stained with Human cytomegalovirus (HCMV) and p16 immunohistochemistry. TIL was calculated in 397 BC cases.

Results:

HCMV was positive in 72.5%. HR- HPV was detected in 2.9% of BC and 1.3% of non-malignant samples. P16+ was found in 28.15% and median TIL percentage was 30. HR- HPV infection was associated with non-ductal histology (p=0.003) and p16+ (p=0.017). Positive P16+ was associated with higher T stage (p=0.022), grade (p=0.009), TIL level (p=0.002), and triple-negative phenotype (p=0.021).

Conclusion:

HCMV is frequent, but HR- HPV infection is unusual in Peruvian BC. P16+ is associated with HR- PVH infection, high TIL and aggressive features.

Regulatory T Cells with Additional COX-2 Expression Are Independent Negative Prognosticators for Vulvar Cancer Patients

Vulvar cancer incidence numbers have been steadily rising over the past decades. In particular, the number of young patients with vulvar cancer has recently increased. Therefore, the need to identify new prognostic factors and, in addition, therapeutic options for vulvar carcinoma is more apparent. The aim of this study was to analyze the influx of COX-2 positive tumor-infiltrating lymphocytes and monocytes and their influence on prognosis. Using subtyping by immunofluorescence, the majority of COX-2 expressing immune cells were identified as FOXP3-positive regulatory T cells. In addition, peri- and intra-tumoral macrophages in the same tumor tissue were detected simultaneously as M2-polarized macrophages. COX-2 positive immune cells were independent negative prognostic markers in long-term overall survival of patients with vulvar cancer. These results show an influence of immune cell infiltration for vulvar carcinoma patients. Immune cell infiltration and immune checkpoint expression may, therefore, become interesting targets for further research on new vulvar cancer treatment strategies.

Tumor-infiltrating lymphocytes for adoptive cell therapy: recent advances, challenges, and future directions

INTRODUCTION

Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TILs) is a highly personalized type of cancer immunotherapy. TIL-based ACT exploits naturally occurring TILs, derived from the patients' tumor. This treatment has shown consistent clinical responses in melanoma, and recent results point toward a potential use in multiple cancer diagnoses. However, several limitations have restricted the clinical development and adaptation of TIL-based ACT.

AREAS COVERED

In this review, we present the principles of TIL-based ACT and discuss the most significant limitations for therapeutic efficacy and its widespread application. The topics of therapeutic resistance (both innate and acquired), treatment-related toxicity, and the novel research topic of metabolic barriers in the tumor microenvironment (TME) are covered.

EXPERT OPINION

There are many ongoing areas of research focusing on improving clinical efficacy and optimizing TIL-based ACT. Many strategies have shown great potential, particularly strategies advancing TIL efficacy (such as increasing and harnessing ex vivo the sub-population of tumor-reactive TILs) and manufacturing processes. Novel approaches can help overcome current limitations and potentially result in TIL-based ACT entering the mainstream of cancer therapy across tumor types.

Transcriptomic profiles of neoantigen-reactive T cells in human gastrointestinal cancers

Tumor-infiltrating neoantigen-reactive T cells can mediate regression of metastatic gastrointestinal cancers yet remain poorly characterized. We performed immunological screening against personalized neoantigens in combination with single-cell RNA sequencing on tumor-infiltrating lymphocytes from bile duct and pancreatic cancer patients to characterize the transcriptomic landscape of neoantigen-reactive T cells. We found that most neoantigen-reactive CD8⁺ T cells displayed an exhausted state with significant CXCL13 and GZMA co-expression compared with non-neoantigen-reactive bystander cells. Most neoantigen-reactive CD4⁺ T cells from a patient with bile duct cancer also exhibited an exhausted phenotype but with overexpression of HOPX or ADGRG1 while lacking IL7R expression. Thus, neoantigen-reactive T cells infiltrating gastrointestinal cancers harbor distinct transcriptomic signatures, which may provide new opportunities for harnessing these cells for therapy.

Is there any correlation between tumor infiltrating lymphocytes and expression of EGFR in squamous cell carcinoma of head and neck? A retrospective observational study

BACKGROUND

: The dismal survival of one of the commonest malignancies of the world, head neck squamous cell carcinomas (HNSCC), has prompted researchers to probe into its various characteristics, especially those which reflect the outcome. Over the years, even though epidermal growth factor receptor (EGFR) and tumor-infiltrating lymphocytes (TIL) have emerged as useful biomarkers of the disease, the two parameters have rarely been considered in conjunction.

AIMS AND OBJECTIVES

The study aimed to assess if there is any correlation between TIL levels (both stromal and intratumoral) and site, grade, stage, and EGFR score of HNSCC.

MATERIALS AND METHODS

A retrospective observational study was conducted in which histopathologically confirmed cases of HNSCC were included. The site of tumor, grade, stage, stromal and intratumoral TIL levels, and EGFR score were noted for each case. The data were analyzed using standard statistical tests.

RESULTS

The study population consisted of 122 patients with a mean age of 53.8 ± 9.2 years. The oral cavity was the commonest site of tumor (109 cases, 89.3%). Most cases were moderately differentiated (75, 61.5%). Pathological staging showed 66 cases (54%) to be in pT1, and 92 cases (75.4%) to be in pN0. In 68 cases (55.7%), stromal TIL level was high, and intratumoral TIL was low in 102 cases (83.6%). A statistically significant correlation was found between TIL levels and site, grade, pathological stage, and EGFR score of HNSCC.

CONCLUSION

This pioneering study is unique in its exploration of the correlation between two significant biomarkers of HNSCC - TIL and EGFR score.

Tumor Infiltrating Lymphocytes are Prognostic Factors and Can Be Markers of Sensitivity to Chemoradiotherapy in Head and Neck Squamous Cell Carcinoma

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) are assessed by the ratio of the area of lymphocytes infiltrating the stroma. TILs are important in breast cancer and malignant melanoma and are being established as a marker of prognosis and sensitivity to chemotherapy. This has resulted in various therapies being developed in fields such as breast cancer. However, the evaluation of TILs in head and neck squamous cell carcinoma (HNSCC) is not progressing, and the prognosis is still poor. Thus, investigating whether or not the evaluation of TILs is also effective in HNSCC and prognoses can be predicted with just biopsy samples alone is required.

METHODS

This study included 153 patients who were diagnosed with HNSCC between January 2010 and December 2019, underwent treatment, and could be followed up thereafter at our institution.

RESULTS

TILs, overall survival (OS), and progression-free survival (PFS) were evaluated in all patients, the chemoradiotherapy arm, and the surgery arm. The cut-off value for TILs was 50%. In all patients, OS was 69.8% and 40.2% (P = 0.01) and PFS was 58.4% and 31.6% (P = 0.003) in the high and low TIL groups, respectively. Multivariate analyses revealed that TILs independently predicted prognosis. In the chemoradiotherapy arm, OS was 70.8% and 31.6% (P = 0.012) and PFS was 63.4% and 20.3% (P = 0.001) in the high and low TIL groups, respectively. No significant differences were noted in the surgery arm.

CONCLUSIONS

In HNSCC, TILs can be used as a prognosis predictor and chemoradiotherapy biomarker. Assessments can be performed just with hematoxylin-eosin staining and is very simple. This will greatly contribute to report personalized therapy progress. Further evaluations and, thus, prospective clinical multicenter trials are needed to use TILs in clinical practice for HNSCC.

Association of B7-H3 expression with racial ancestry, immune cell density, and androgen receptor activation in prostate cancer

Background

B7 homolog 3 (B7‐H3) is an immunomodulatory molecule that is highly expressed in prostate cancer (PCa) and belongs to the B7 superfamily, which includes PD‐L1. Immunotherapies (antibodies, antibody‐drug conjugates, and chimeric antigen receptor T cells) targeting B7‐H3 are currently in clinical trials; therefore, elucidating the molecular and immune microenvironment correlates of B7‐H3 expression may help to guide trial design and interpretation. The authors tested the interconnected hypotheses that B7‐H3 expression is associated with genetic racial ancestry, immune cell composition, and androgen receptor signaling in PCa.

Methods

An automated, clinical‐grade immunohistochemistry assay was developed by to digitally quantify B7‐H3 protein expression across 2 racially diverse cohorts of primary PCa (1 with previously reported transcriptomic data) and pretreatment and posttreatment PCa tissues from a trial of intensive neoadjuvant hormonal therapy.

Results

B7‐H3 protein expression was significantly lower in self‐identified Black patients and was inversely correlated with the percentage African ancestry. This association with race was independent of the significant association of B7‐H3 protein expression with ERG/ETS and PTEN status. B7‐H3 messenger RNA expression, but not B7‐H3 protein expression, was significantly correlated with regulatory (FOXP3‐positive) T‐cell density. Finally, androgen receptor activity scores were significantly correlated with B7‐H3 messenger RNA expression, and neoadjuvant intensive hormonal therapy was associated with a significant decrease in B7‐H3 protein expression.

Conclusions

The current data underscore the importance of studying racially and molecularly diverse PCa cohorts in the immunotherapy era. This study is among the first to use genetic ancestry markers to add to the emerging evidence that PCa in men of African ancestry may have a distinct biology associated with B7‐H3 expression.

Lay Summary

B7‐H3 is an immunomodulatory molecule that is highly expressed in prostate cancer and is under investigation in clinical trials.

The authors determined that B7‐H3 protein expression is inversely correlated with an individual's proportion of African ancestry.

The results demonstrate that B7‐H3 messenger RNA expression is correlated with the density of tumor T‐regulatory cells.

Finally, in the first paired analysis of B7‐H3 protein expression before and after neoadjuvant intensive hormone therapy, the authors determined that hormone therapy is associated with a decrease in B7‐H3 protein levels, suggesting that androgen signaling may positively regulate B7‐H3 expression.

These results may help to guide the design of future clinical trials and to develop biomarkers of response in such trials.

B7‐H3 protein expression was significantly lower in self‐identified Black patients and was inversely correlated with the percentage African ancestry. Androgen receptor activity scores were significantly correlated with B7‐H3 messenger RNA expression, and neoadjuvant intensive hormonal therapy was associated with a significant decrease in B7‐H3 protein expression, consistent with a presumed androgen receptor binding site upstream of the B7‐H3 promoter.

Lymphocytes Infiltration and Expression of PD-1 and PD-L1 in Colorectal Cancer Between HIV-Infected and Non-HIV-Infected Patients: A Propensity Score Matched Cohort Study

Background

Tumor-infiltrating lymphocytes (TILs) and expression of programmed cell death 1 (PD-1)/programmed death ligand-1 (PD-L1) are crucial for antitumor immunity. However, the status remains undetermined in HIV-infected colorectal cancer (CRC), limiting the use of immunotherapy in HIV-infected CRC patients.

Methods

We examined 27 HIV-infected patients and 120 non-HIV-infected patients with CRC from 2015-2020 at Shanghai Public Health Clinical Center. After matching the propensity score, 13 paired patients in the two groups were also compared. The expression of PD-1/PD-L1 as well as tumor-infiltrating CD4, CD8, and CD56 immune cells was examined using multiplex immunofluorescent analysis. The cell density for positive staining was calculated (cells/mm²) and compared between HIV-infected and non-HIV-infected groups. In addition, the co-expression of PD-1 on immune cells and PD-L1 on tumor cells was compared in these two groups.

Results

The mean densities of tumor-infiltrating CD4, CD8, CD56 immune cells were 620.2, 261.2, and 0.2 cells/mm², respectively, in HIV-infected colorectal tumors compared with 698.6, 243, and 14 cells/mm² in non-HIV-infected tumors. PD-1 expression was 227 cells/mm² in HIV-infected tumors and 365.2 cells/mm² in non-HIV-infected tumors. Besides, PD-L1 expression was 108.5 cells/mm² in HIV-infected tumors and 126.8 cells/mm² in non-HIV-infected tumors, and no significant difference was found between the two groups. Similarly, there were no significant differences in the expression of PD-1 on TILs and PD-L1 on tumor cells.

Conclusion

HIV-infected CRC patients had similar tumor-infiltrating lymphocytes (CD4 and CD8 T cells) compared to non-HIV-infected controls and substantially similar PD-1 expression on TILs and PD-L1 expression on tumors. These results support the inclusion of HIV-infected CRC patients in future immunotherapy trials.

Magnetic resonance imaging of tumor-infiltrating lymphocytes by anti-CD3-conjugated iron oxide nanoparticles

Immune checkpoint blockade, considered a revolutionary approach in cancer treatment, is only effective in patients with high tumor-infiltrating lymphocytes (TILs). This work aimed to investigate the feasibility of targeted contrast agent (CA) based on dextran-coated superparamagnetic iron oxide nanoparticles (SPIONs-DEX) for TILs detection by magnetic resonance imaging (MRI) studies. To do so, we synthesized an MRI CA by conjugating SPIONs-DEX to an anti-CD3 monoclonal antibody via cyanogen bromide as a cross-linker. In vitro assessments demonstrated the higher labeling efficiency of the developed CA to CD3+ lymphocytes compared to SPIONs-DEX. In vivo MRI of a xenograft model of CD3+ lymphocytes revealed the significant signal loss after the intravenous injection of the bioconjugate by ~ 34% and 21% in T 2 * -weighted and T 2 -weighted images, respectively. The histopathological evaluation of xenograft tumors confirmed the labeling of lymphocytes by the targeted CA. This approach could open up a new horizon in the non-invasive assessment of TILs to identify patients eligible for immunotherapy.

Highly efficient PD-1-targeted CRISPR-Cas9 for tumor-infiltrating lymphocyte-based adoptive T cell therapy

Adoptive T cell therapy (ACT) with expanded tumor-infiltrating lymphocytes (TIL) can induce durable responses in cancer patients from multiple histologies, with response rates of up to 50%. Antibodies blocking the engagement of the inhibitory receptor programmed cell death protein 1 (PD-1) have been successful across a variety of cancer diagnoses. We hypothesized that these approaches could be combined by using CRISPR-Cas9 gene editing to knock out PD-1 in TILs from metastatic melanoma and head-and-neck, thyroid, and colorectal cancer. Non-viral, non-plasmid-based PD-1 knockout was carried out immediately prior to the traditional 14-day TIL-based ACT rapid-expansion protocol. A median 87.53% reduction in cell surface PD-1 expression was observed post-expansion and confirmed at the genomic level. No off-target editing was detected, and PD-1 knockout had no effect on final fold expansion. Edited cells exhibited few phenotypic differences and matched control functionality. Pre-clinical-scale results were confirmed at a clinical scale by generating a PD-1-deficient TIL product using the good manufacturing practice facilities, equipment, procedures, and starting material used for standard patient treatment. Our results demonstrate that simple, non-viral, non-plasmid-based CRISPR-Cas9 methods can be feasibly adopted into a TIL-based ACT protocol to produce treatment products deficient in molecules such as PD-1, without any evident negative effects.

Promoting antigen escape from dendritic cell endosomes potentiates anti-tumoral immunity

The cross-presenting capacity of dendritic cells (DCs) can be limited by non-specific degradation during endosome maturation. To bypass this limitation, we present in this study a new Accum-based formulation designed to promote endosome-to-cytosol escape. Treatment of primary DCs with Accum linked to the xenoantigen ovalbumin (OVA) triggers endosomal damages and enhances protein processing. Despite multiple challenges using ascending doses of tumor cells, DC prophylactic vaccination results in complete protection due to increased levels of effector CD4 and CD8 T cells as well as high production of pro-inflammatory mediators. When combined with anti-PD-1, therapeutic vaccination using both syngeneic and allogeneic Accum-OVA-pulsed DCs triggers potent anti-tumoral responses. The net outcome culminates in increased CD11c, CD8, and NK infiltration along with a high CD8/Treg ratio. These highly favorable therapeutic effects highlight the promising potential of Accum as a distinct and potent technology platform suitable for the design of next generation cell cancer vaccines.

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Accum-linked antigen enhances antigen processing and presentation

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Pulsed dendritic cells elicit potent effector T cell responses

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Therapeutic vaccination using allogeneic DCs controls pre-established tumors

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The vaccine boosts tumor-infiltrating lymphocytes and increases the CD8/Treg ratio

Transcriptional Expressions of ALDH1A1/B1 as Independent Indicators for the Survival of Thyroid Cancer Patients

Background

Aldehyde dehydrogenase (ALDH) 1 is an important enzyme involved in the regulation of several cellular mechanisms via aldehyde detoxification. High ALDH1 levels were correlated with tumorigenesis and stemness maintenance in cancer.

Methods

We used UALCAN, Human Protein Atlas, Kaplan–Meier plotter, TISIDB, TIMER, and KOBAS databases to investigate the expression and role of ALDH1 in thyroid cancer progression. In addition, quantitative real-time polymerase chain reaction was performed to detect the expression of the target genes in thyroid cancer cell lines and cancer tissues.

Results

Expression of ALDH1A1/B1 was significantly decreased based on individual cancer stages and tumor histology, and high levels of ALDH1A1/B1 were associated with poor overall survival in thyroid cancer patients. Moreover, ALDH1A1/B1 expression was negatively correlated with immune-stimulating genes, major histocompatibility complex, chemokines, and receptors.

Conclusions

These results suggest that ALDH1A1/B1 might serve as potential prognostic biomarkers for thyroid cancer diagnosis.

Tumor-associated high endothelial venules mediate lymphocyte entry into tumors and predict response to PD-1 plus CTLA-4 combination immunotherapy

Recruitment of lymphocytes into tumors is critical for anti-tumor immunity and efficacious immunotherapy. We show in murine models that tumor-associated high endothelial venules (TA-HEVs) are major sites of lymphocyte entry into tumors at baseline and upon treatment with anti-PD-1/anti-CTLA-4 immune checkpoint blockade (ICB). TA-HEV endothelial cells (TA-HECs) derive from post-capillary venules, co-express MECA-79⁺ HEV sialomucins and E/P-selectins, and are associated with homing and infiltration into tumors of various T cell subsets. Intravital microscopy further shows that TA-HEVs are the main sites of lymphocyte arrest and extravasation into ICB-treated tumors. Increasing TA-HEC frequency and maturation increases the proportion of tumor-infiltrating stem-like CD8⁺ T cells, and ameliorates ICB efficacy. Analysis of tumor biopsies from 93 patients with metastatic melanoma reveals that TA-HEVs are predictive of better response and survival upon treatment with anti-PD-1/anti-CTLA-4 combination. These studies provide critical insights into the mechanisms governing lymphocyte trafficking in cancer immunity and immunotherapy.

Patterns of Tumor Infiltrating Lymphocytes in Adenoid Cystic Carcinoma of the Head and Neck

Simple Summary

Adenoid cystic carcinoma (ACC) is a rare tumor with late occurring metastases and recurrences, which makes it necessary for patients to be monitored closely even beyond the usual five years. So far, there is hardly any effective treatment in the palliative situation and trials on immunotherapeutic drugs have not been successful. We sought to find possible prognostic markers by analyzing patterns of tumor infiltrating immune cells and additionally to learn more about possible reasons for this lack of response to immunotherapy. It appears from our data that it is not relevant for prognosis if the tumor is infiltrated by immune cells. This might also be the reason that immunotherapies do not work in this particular disease, which suggests that ACC is not recognized by infiltrating immune cells. Therefore, the tumor would have to be made visible to the immune system, for example, through vaccinations.

Abstract

Adenoid cystic carcinoma (ACC) is a rare malignancy in the head and neck. The prognosis remains poor and late recurrences often occur after 5 years and later. To date, there are no reliable prognostic markers for ACC. In several solid tumors, tertiary lymphoid structures (TLS) are associated with improved survival. This study aims to investigate the role of distribution patterns of tumor infiltrating immune cells (TIL) in ACC. A cohort of 50 patients from three different cancer centers was available for analysis. Sections were stained for CD3, CD4, CD8 and CD20 and evaluated with regard to their distribution of TIL. Patterns were determined as infiltrated-excluded, infiltrated-inflamed and presence of tertiary lymphoid structures. About half of the cases showed an infiltrated-excluded TIL pattern and only a minority of six cases had TLS present within the tumor. Within the inflamed phenotype CD3+ cells were by far the most abundant lymphocyte subtype, and within this compartment, CD8+ T cells were predominant. There was no influence on overall or disease-free survival by any of the TIL patterns. This indicates that ACC is a tumor with very low immunogenicity and even abundance of lymphocytes does not seem to improve prognosis for this disease. Therefore, the observed lack of response towards immunotherapy is not surprising and other methods to induce recognition of ACC by the immune system must be found.

Tumor-Infiltrating Lymphocytes in Patients With Advanced Laryngeal Cancer Undergoing Bioselection

OBJECTIVE

Bioselection to assess tumor response after induction chemotherapy has been introduced as an alternative treatment strategy to total laryngectomy for patients with advanced larynx squamous cell carcinoma (LSCC). Tumor-infiltrating lymphocytes (TILs) have proven to serve as prognostic biomarkers in head and neck cancer but have not been evaluated as a way to select patients for treatment paradigms. The aim of this study is to evaluate the role of pretreatment TILs in patients with advanced LSCC undergoing the bioselection paradigm.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary care hospital.

METHODS

Patients with advanced LSCC treated with bioselection and available tissue were included (N = 76). Patients were stratified into CD8-low and CD8-high cohorts by using the median TIL count. Kaplan-Meier survival analysis and multivariate cox regression were performed with SPSS version 26 (IBM).

RESULTS

After controlling for tobacco use, tumor site, and stage, a high CD8 TIL count was an independent predictor of improved 5-year disease-specific survival (hazard ratio, 0.17 [95% CI, 0.03-0.84]; P = .03). CD8 TIL counts did not predict response to induction chemotherapy; however, subgroup analysis of patients treated with chemoradiation therapy revealed that CD8 TIL count was significantly associated with degree of response (P = .012).

CONCLUSION

These findings support prior data published by our group showing that TILs are predictive of disease-specific survival in patients with head and neck cancer. CD8 TIL counts were significantly associated with degree of clinical response after induction chemotherapy. These results suggest that pretreatment assessment of tumor-infiltrating CD8 cells could be useful in selecting patients.

Pan-immune-inflammation Value and Prognosis in Patients With Esophageal Cancer

Mini-abstract

The pan-immune-inflammation value was associated with clinical outcomes and tumor-infiltrating lymphocytes in 866 esophageal cancers. Systemic immune competence may influence patient prognosis through local immune response.

Objective

To examine the relationship between the pan-immune-inflammation value (PIV), tumor immunity, and clinical outcomes in 866 patients with esophageal cancer.

Background

The PIV, calculated from all immune-inflammatory cells in the peripheral blood count, is a recently proposed marker for clinical outcomes in some types of cancers. Nonetheless, the prognostic significance of PIV in esophageal cancer remains unclear.

Methods

In the derivation cohort (n = 433), we set the optimal cutoff value using a time-dependent receiver operating characteristic (ROC) curve. In the validation cohort (n = 433), the relationships between the PIV, tumor-infiltrating lymphocytes (TILs), CD8 expression by immunohistochemical staining, and patient prognosis were examined.

Results

The area under the ROC curve for the PIV at 5 years was 0.631 in the derivation cohort. The validation cohort, divided into PIV-low cases (n = 223) and PIV-high cases (n = 210), showed significantly worse overall survival (log-rank P = 0.0065; hazard ratio [HR]: 1.48; 95% confidence interval [CI]: 1.12-1.98; P < 0.001; multivariate HR: 1.41; 95% CI: 1.05-1.90; P = 0.023). The prognostic effect of the PIV was not significantly modified by any clinical characteristics (P for interaction > 0.05). The PIV-high cases were significantly associated with a low TIL status (P < 0.001) and low CD8-positive cell counts (P = 0.011).

Conclusions

The PIV was associated with clinical outcomes in esophageal cancer, supporting its role as a prognostic biomarker. Considering the relationship between the PIV and TILs, systemic immune competence may influence patient prognosis through a local immune response.

Prognostic Landscape of Tumor-Infiltrating T and B Cells in Human Cancer

Recently, immunotherapy targeting tumor-infiltrating lymphocytes (TILs) has emerged as a critical and promising treatment in several types of cancer. However, not all cancer types have been tested in immunotherapeutic trials, and different patients and cancer types may have unpredictable clinical outcomes. This situation has created a particular exigency for analyzing the prognostic significance of tumor-infiltrating T cells (TIL-T) and B cells (TIL-B) across different cancer types. To address the critical role of TILs, the abundances of TIL-T and TIL-B cells, as determined by the protein levels of LCK and CD20, were analyzed across heterogeneous human malignancies. TIL-T and TIL-B cells showed varying prognostic significances across heterogeneous cancer types. Additionally, distinct distributions of TIL-T and TIL-B cells were observed in different cancer and tumor microenvironment (TME) subtypes. Next, we analyzed the cellular context for the TME communication network involving the well-acknowledgeable chemokine receptors of TIL-T and TIL-B cells, implying the functional interactions with TME. Additionally, these chemokine receptors, expressed by TIL-T and TIL-B cells, were remarkably correlated with the levels of TIL-T or TIL-B cell infiltrations across nearly all the cancer types, indicating these chemokine receptors as universal targets for up- and down-regulating the TIL-T and TIL-B cells. Lastly, we provide the prognostic landscape of TIL-T and TIL-B cells across 30 cancer types and the subgroups defined by gender, histopathology, histological grade, therapeutic approach, drug, and TME subtype, which are intended to be a resource to fuel the investigations of TILs, with important implications for cancer immunotherapy.

Tumor-Infiltrating Lymphocytes in Colorectal Cancer: The Fundamental Indication and Application on Immunotherapy

The clinical success of immunotherapy has revolutionized the treatment of cancer patients, bringing renewed attention to tumor-infiltrating lymphocytes (TILs) of various cancer types. Immune checkpoint blockade is effective in patients with mismatched repair defects and high microsatellite instability (dMMR-MSI-H) in metastatic colorectal cancer (CRC), leading the FDA to accelerate the approval of two programmed cell death 1 (PD-1) blocking antibodies, pembrolizumab and nivolumab, for treatment of dMMR-MSI-H cancers. In contrast, patients with proficient mismatch repair and low levels of microsatellite stability or microsatellite instability (pMMR-MSI-L/MSS) typically have low tumor-infiltrating lymphocytes and have shown unsatisfied responses to the immune checkpoint inhibitor. Different TILs environments reflect different responses to immunotherapy, highlighting the complexity of the underlying tumor-immune interaction. Profiling of TILs fundamental Indication would shed light on the mechanisms of cancer-immune evasion, thus providing opportunities for the development of novel therapeutic strategies. In this review, we summarize phenotypic diversities of TILs and their connections with prognosis in CRC and provide insights into the subsets-specific nature of TILs with different MSI status. We also discuss current clinical immunotherapy approaches based on TILs as well as promising directions for future expansion, and highlight existing clinical data supporting its use.

Use of Patient-Derived Organoids as a Treatment Selection Model for Colorectal Cancer: A Narrative Review

Simple Summary

Colorectal cancer (CRC) is the third most common type of cancer globally. Despite successful treatment, it has a 40% chance of recurrence within five years after surgery. While neoadjuvant chemotherapy is offered for stage IV cancers, it comes with a risk of resistance and disease progression. CRC tumors vary biologically, recur frequently, and pose a significant risk for cancer-related mortality, making it increasingly relevant to develop methods to study personalized treatment. A tumor organoid is a miniature, multicellular, and 3D replica of a tumor in vitro that retains its characteristics. Here, we discuss the current methods of culturing organoids and the correlation of drug response in organoids with clinical responses in patients. This helps us to determine whether organoids can be used for treatment selection in a clinical setting. Based on the studies included, there was a strong correlation between treatment responses of organoids and clinical treatment responses.

Abstract

Surgical resection is the mainstay in intended curative treatment of colorectal cancer (CRC) and may be accompanied by adjuvant chemotherapy. However, 40% of the patients experience recurrence within five years of treatment, highlighting the importance of improved, personalized treatment options. Monolayer cell cultures and murine models, which are generally used to study the biology of CRC, are associated with certain drawbacks; hence, the use of organoids has been emerging. Organoids obtained from tumors display similar genotypic and phenotypic characteristics, making them ideal for investigating individualized treatment strategies and for integration as a core platform to be used in prediction models. Here, we review studies correlating the clinical response in patients with CRC with the therapeutic response in patient-derived organoids (PDO), as well as the limitations and potentials of this model. The studies outlined in this review reported strong associations between treatment responses in the PDO model and clinical treatment responses. However, as PDOs lack the tumor microenvironment, they do not genuinely account for certain crucial characteristics that influence therapeutic response. To this end, we reviewed studies investigating PDOs co-cultured with tumor-infiltrating lymphocytes. This model is a promising method allowing evaluation of patient-specific tumors and selection of personalized therapies. Standardized methodologies must be implemented to reach a “gold standard” for validating the use of this model in larger cohorts of patients. The introduction of this approach to a clinical scenario directing neoadjuvant treatment and in other curative and palliative treatment strategies holds incredible potential for improving personalized treatment and its outcomes.

Multi-Omics Profiling Suggesting Intratumoral Mast Cells as Predictive Index of Breast Cancer Lung Metastasis

Breast cancer lung metastasis has a high mortality rate and lacks effective treatments, for the factors that determine breast cancer lung metastasis are not yet well understood. In this study, data from 1067 primary tumors in four public datasets revealed the distinct microenvironments and immune composition among patients with or without lung metastasis. We used multi-omics data of the TCGA cohort to emphasize the following characteristics that may lead to lung metastasis: more aggressive tumor malignant behaviors, severer genomic instability, higher immunogenicity but showed generalized inhibition of effector functions of immune cells. Furthermore, we found that mast cell fraction can be used as an index for individual lung metastasis status prediction and verified in the 20 human breast cancer samples. The lower mast cell infiltrations correlated with tumors that were more malignant and prone to have lung metastasis. This study is the first comprehensive analysis of the molecular and cellular characteristics and mutation profiles of breast cancer lung metastasis, which may be applicable for prognostic prediction and aid in choosing appropriate medical examinations and therapeutic regimens.

Tumor-infiltrating lymphocytes predict improved overall survival after post-mastectomy radiotherapy: a study of the randomized DBCG82bc cohort

BACKGROUND

The predictive value of tumor-infiltrating lymphocytes (TILs) on the benefit from radiotherapy (RT) remains unclear. Our aim was to investigate the association between TILs and post-mastectomy RT (PMRT) regarding the risk of recurrence and survival in a randomized cohort.

MATERIAL AND METHODS

Stromal TILs were histologically estimated in 1011 tumors from high-risk breast cancer (BC) patients from the DBCG82bc trial. Patients were diagnosed between 1982 and 90, treated with total mastectomy and partial axillary lymph node dissection, randomized to ± PMRT followed by adjuvant systemic treatment. A competing risk model, Kaplan-Meier analysis and multivariate Cox regression analysis were used for correlating TILs and clinical outcome.

RESULTS

106 of 1011 patients (10.5%) showed high TILs using a 30% cut-off. In multivariate regression analysis, a high level of TILs was an independent factor associated with lower risk of distant metastasis (DM) and improved overall survival (OS), but without association with loco-regional control. High TILs were associated with a significantly greater OS after PMRT at 20 years compared to low TILs (8% improvement for low TILs (23% to 31%) vs. 22% for high TILs (26% to 48%), interaction-test: p = 0.028). The association between TILs and PMRT was more pronounced among estrogen-receptor negative (ER-) tumors, and patients having ER-/low TILs tumors showed no OS benefit from PMRT at 20 years (-4% improvement for low TILs (28% to 24%) vs. 23% for high TILs (20% to 43%). A similar trend in the association between high TILs and reduced risk of DM after PMRT was seen.

CONCLUSION

High TILs predict improved OS from PMRT in BC patients, and the association appeared especially strong for ER- tumors. A trend in the association between high TILs and reduced risk of DM after PMRT was seen. These findings may indicate that RT triggers an immune response inducing a systemic effect outside the treatment field.

Tumor-Infiltrating Lymphocytes as Biomarkers of Treatment Response and Long-Term Survival in Patients with Rectal Cancer: A Systematic Review and Meta-Analysis

Simple Summary

This study investigated tumor-infiltrating lymphocytes (TILs) in pretherapeutic biopsies as biomarkers of treatment response and long-term prognosis in patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy. A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. The results indicate that it is possible to identify a sub-group of patients with improved treatment response and long-term prognosis by assessing the density of CD8⁺ TILs at the time of diagnosis.

Abstract

Neoadjuvant chemoradiotherapy (NCRT) is indicated in locally advanced rectal cancer (LARC) to downstage tumors before surgery. Watchful waiting may be a treatment option to avoid surgery in patients, obtaining a complete clinical response. However, biomarkers predictive of treatment response and long-term prognosis are lacking. Here we investigated tumor-infiltrating lymphocytes (TILs) in pretherapeutic biopsies as predictive and prognostic biomarkers. A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. In total, 429 articles were identified, of which 19 studies were included in the systematic review and 14 studies in the meta-analysis. Patients with high pretherapeutic CD8⁺ TILs density had an increased likelihood of achieving a pathological complete response (RR = 2.71; 95% CI: 1.58–4.66) or a complete or near-complete pathological treatment response (RR = 1.86; 95% CI: 1.50–2.29). Furthermore, high CD8⁺ TILs density was a favorable prognostic factor for disease-free survival (HR = 0.57; 95% CI: 0.38–0.86) and overall survival (HR = 0.43; 95% CI: 0.27–0.69). CD3⁺, CD4⁺, and FOXP3⁺ TILs were not identified as predictive or prognostic biomarkers. Thus, assessing pretherapeutic CD8⁺ TILs density may assist in identifying patients with increased sensitivity to NCRT and favorable long-term prognosis.

T- and B-Cells in the Inner Invasive Margin of Hepatocellular Carcinoma after Resection Associate with Favorable Prognosis

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world, which frequently recurs after curative resection. Several options to predict recurrence of HCC have been proposed, however, their prognostic ability is limited. This study aimed to test the hypothesis that distribution and numbers of T- and B-lymphocytes in different regions of the resected tumor may have different prognostic significance. Different subregions of HCC demonstrated uneven lymphocyte infiltration. CD20+ B-lymphocytes and CD8+ T-lymphocytes, or their combination in the inner tumor invasive margin and inner/outer margin ratios, convey the best prediction for time to recurrence and disease-free survival. The results offer a novel approach to the stratification of the risk of early tumor recurrence after curative liver resection.

Abstract

In this retrospective study on 67 patients with hepatocellular carcinoma (HCC), after tumor resection, we evaluated the significance of CD3+ and CD8+ T-lymphocytes and CD20+ B-lymphocytes in tumor and non-tumor liver for time to recurrence (TTR), disease-free survival (DFS) and overall survival. After immunohistochemical staining, the density of nucleated lymphocyte profiles (Q_A) was estimated stereologically in the tumor center (TC), inner margin (inn M), outer margin (out M), peritumor and non-tumor liver. In TC, intermediate and high Q_A of CD8+ cells predicted longer TTR, whereas CD3+ and CD20+ were predictive only at high Q_A. DFS was predicted by high Q_A of CD3+, CD8+ and CD20+ cells in TC. The inn M harbored smaller Q_A of CD3+, CD8+ and CD20+ lymphocytes than out M. In contrast to out M, high T-cells’ Q_A and intermediate and high B-cell Q_A in inn M predicted longer TTR and DFS. High inn M/out M Q_A ratios of CD3+ and CD20+ cells were associated with longer TTR and DFS, whereas high inn M/out M Q_A ratio of CD8+ was predictive only for DFS. Patients with intermediate-high Q_A of combined CD8+ and CD20+ cells in inn M showed longer TTR and DFS, compared to CD8+-high or CD20+-high alone. Our findings highlight overall heterogeneity of the tumor invasive margin, the importance of inn M, and the predictive role of B-cells.

Tumor-infiltrating lymphocytes are functionally inactivated by CD90+ stromal cells and reactivated by combined Ibrutinib and Rapamycin in human pleural mesothelioma

Rationale: Despite evidence suggesting that the tumor microenvironment (TME) in malignant pleural mesothelioma (MPM) is linked with poor prognosis, there is a lack of studies that functionally characterize stromal cells and tumor-infiltrating lymphocytes (TILs). Here, we aim to characterize the stromal subsets within MPM, investigate their relationship to TILs, and explore the potential therapeutic targets.

Methods: We curated a core set of genes defining stromal/immune signatures expressed by mesenchymal cells within the TME using molecular analysis of The Cancer Genome Atlas (TCGA) MPM cohort. Stromal and immune profiles were molecularly characterized using flow cytometry, immunohistochemistry, microarray, and functionally evaluated using T cell-activation/expansion, coculture assays and drug compounds treatment, based on samples from an independent MPM cohort.

Results: We found that a high extracellular matrix (ECM)/stromal gene signature, a high ECM score, or the ratio of ECM to an immune activation gene signature are significantly associated with poor survival in the MPM cohort in TCGA. Analysis of an independent MPM cohort (n = 12) revealed that CD8+ and CD4+ TILs were characterized by PD1 overexpression and concomitant downregulation in degranulation and CD127. This coincided with an increase in CD90+ cells that overexpressed PD-L1 and were enriched for ECM/stromal genes, activated PI3K-mTOR signaling and suppressed T cells. Protein array data demonstrated that MPM samples with high PD-L1 expression were most associated with activation of the mTOR pathway. Further, to reactivate functionally indolent TILs, we reprogrammed ex vivo TILs with Ibrutinib plus Rapamycin to block interleukin-2-inducible kinase (ITK) and mTOR pathways, respectively. The combination treatment shifted effector memory (T_EM) CD8+ and CD4+ TILs towards T cells that re-expressed CD45RA (T_EMRA) while concomitantly downregulating exhaustion markers. Gene expression analysis confirmed that Ibrutinib plus Rapamycin downregulated coinhibitory and T cell signature pathways while upregulating pathways involved in DNA damage and repair and immune cell adhesion and migration.

Conclusions: Our results suggest that targeting the TME may represent a novel strategy to redirect the fate of endogenous TILs with the goal of restoring anti-tumor immunity and control of tumor growth in MPM.

Breast Cancer Tumor Microenvironment and Molecular Aberrations Hijack Tumoricidal Immunity

Simple Summary

Immune therapy is designed to stimulate tumoricidal effects in a variety of solid tumors including breast carcinomas. However, the emergence of resistant clones leads to treatment failure. Understanding the molecular, cellular, and microenvironmental aberrations is crucial to uncovering underlying mechanisms and developing advanced strategies for preventing or combating these resistant malignancies. This review will summarize research findings revealing various mechanisms employed to hijack innate and adaptive immune surveillance mechanisms, develop hypoxic and tumor promoting metabolism, and foster an immune tolerance microenvironment. In addition, it will highlight potential targets for therapeutic approaches.

Abstract

Breast cancer is the most common malignancy among females in western countries, where women have an overall lifetime risk of >10% for developing invasive breast carcinomas. It is not a single disease but is composed of distinct subtypes associated with different clinical outcomes and is highly heterogeneous in both the molecular and clinical aspects. Although tumor initiation is largely driven by acquired genetic alterations, recent data suggest microenvironment-mediated immune evasion may play an important role in neoplastic progression. Beyond surgical resection, radiation, and chemotherapy, additional therapeutic options include hormonal deactivation, targeted-signaling pathway treatment, DNA repair inhibition, and aberrant epigenetic reversion. Yet, the fatality rate of metastatic breast cancer remains unacceptably high, largely due to treatment resistance and metastases to brain, lung, or bone marrow where tumor bed penetration of therapeutic agents is limited. Recent studies indicate the development of immune-oncological therapy could potentially eradicate this devastating malignancy. Evidence suggests tumors express immunogenic neoantigens but the immunity towards these antigens is frequently muted. Established tumors exhibit immunological tolerance. This tolerance reflects a process of immune suppression elicited by the tumor, and it represents a critical obstacle towards successful antitumor immunotherapy. In general, immune evasive mechanisms adapted by breast cancer encompasses down-regulation of antigen presentations or recognition, lack of immune effector cells, obstruction of anti-tumor immune cell maturation, accumulation of immunosuppressive cells, production of inhibitory cytokines, chemokines or ligands/receptors, and up-regulation of immune checkpoint modulators. Together with altered metabolism and hypoxic conditions, they constitute a permissive tumor microenvironment. This article intends to discern representative incidents and to provide potential innovative therapeutic regimens to reinstate tumoricidal immunity.

Spatial and Temporal Heterogeneity of Tumor-Infiltrating Lymphocytes in Advanced Urothelial Cancer

Checkpoint inhibitors targeting PD-(L)1 induce objective responses in 20% of patients with metastatic urothelial cancer (UC). CD8+ T cell infiltration has been proposed as a putative biomarker for response to checkpoint inhibitors. Nevertheless, data on spatial and temporal heterogeneity of tumor-infiltrating lymphocytes in advanced UC are lacking. The major aims of this study were to explore spatial heterogeneity for lymphocyte infiltration and to investigate how the immune landscape changes during the disease course. We performed multiplex immunohistochemistry to assess the density of intratumoral and stromal CD3+, CD8+, FoxP3+ and CD20+ immune cells in longitudinally collected samples of 49 UC patients. Within these samples, spatial heterogeneity for lymphocyte infiltration was observed. Regions the size of a 0.6 tissue microarray core (0.28 mm2) provided a representative sample in 60.6 to 71.6% of cases, depending on the cell type of interest. Regions of 3.30 mm2, the median tumor surface area in our biopsies, were representative in 58.8 to 73.8% of cases. Immune cell densities did not significantly differ between untreated primary tumors and metachronous distant metastases. Interestingly, CD3+, CD8+ and FoxP3+ T cell densities decreased during chemotherapy in two small cohorts of patients treated with neoadjuvant or palliative platinum-based chemotherapy. In conclusion, spatial heterogeneity in advanced UC challenges the use of immune cell infiltration in biopsies as biomarker for response prediction. Our data also suggests a decrease in tumor-infiltrating T cells during platinum-based chemotherapy.

Cancer-associated fibroblasts and the tumor microenvironment in non-small cell lung cancer

INTRODUCTION

Non-small cell lung cancer (NSCLC) has a markedly poor prognosis as it progresses, and the prognosis is still unsatisfactory even with modern treatments. Cancer is composed of not only cancer cells, but also stroma consisting of various cell types. Cancer-associated fibroblasts (CAFs) are a major component of the stroma and the associated tumor microenvironment (TME). Particularly, CAFs are a critical component in elucidating the biological mechanisms of cancer progression and new therapeutic targets. This article outlines the TME formed by CAFs in NSCLC.

AREAS COVERED

Focusing on the TME in NSCLC, we discuss the mechanisms by which CAFs are involved in cancer progression, drug resistance, and the development of therapies targeting CAFs.

EXPERT OPINION

In the TME, CAFs profoundly contribute to tumor progression by interacting with cancer cells through direct contact or paracrine cytokine signaling. CAFs also interact with various other stromal components to establish a tumor-promoting immunosuppressive microenvironment and remodel the extracellular matrix. Furthermore, these effects are closely associated with drug resistance. Further elucidation of the stromal microenvironment, including CAFs, could prove to be crucial in the treatment of NSCLC.