Density Of Tumor-infiltrating Lymphocytes Research Articles

Interim analysis of first-in-human phase 1 study to assess safety and efficacy of YBL-006, an anti-PD-1 antibody in advanced solid tumor with exploratory biomarker analysis of tumor mutational burden and artificial intelligence (AI)-powered spatial analysis of tumor-infiltrating lymphocytes.

e14552 Background: YBL-006 is an anti-programmed death-1 (PD-1) antibody with a higher affinity compared to that of other PD-1 antibodies, which showed a favorable safety profile in animal models. We designed the first-in-human phase I trial of YBL-006 to assess its safety and efficacy with exploratory biomarker analysis in patients with advanced solid tumors refractory to standard of treatment. Methods: A modified “3+3” design, with the first patient dosed at 0.5 mpk, was followed by conventional dose escalation of 2, 5, and 10 mpk IV. Pharmacokinetics (PK) and pharmacodynamics, including PD-1 receptor occupancy (RO) and serum levels of interferon-gamma (IFN-γ), were assessed. Adverse events (AEs) were graded using the CTCAE v4.03. Tumor response was assessed using the RECIST v1.1 every 8 weeks. For exploratory analysis, tumor mutational burden (TMB) and AI-powered spatial analysis of tumor-infiltrating lymphocyte (TIL) of tumor tissues collected before YBL-006 treatment were performed. The cut-off date for analysis was February 12, 2021. Results: A total of 8 patients enrolled in the 0.5, 2, and 5 mpk cohorts received at least one dose of YBL-006 and median exposure was 15 weeks (ranged 4-26). No dose limiting toxicity occurred and the maximum tolerated dose was not reached until progressing to the 5 mpk. The common treatment-related AEs were G1 fatigue (25%), and G1 hypothyroidism (12.5%). We also observed 1 case of G2 cytokine release syndrome during cycle 1 in 2 mpk which was managed with supportive care alone. No treatment-related deaths have occurred to date. YBL-006 showed a linear PK prolife and both PD-1 RO and serum IFN-γ increased by > 2 times 8 h after the first dose. Tumor evaluation data were available for 7 patients, which showed 1 confirmed complete response (CR, penile squamous cell carcinoma, 2 mpk) and 1 confirmed partial response (PR, anal squamous cell carcinoma, 2 mpk) with durable responses lasting more than 19+ and 10+ weeks respectively, 2 stable disease (SD) and 3 progressive disease (PD). Four tumor samples were available for biomarker analysis. TMBs of patients with CR (8.3/Mb) or PR (9.3/Mb) were higher than those in 2 patients with PD (5.5 and 1.7/Mb). AI-powered spatial analysis of TIL showed that intratumoral TIL density was increased in patients who achieved CR and PR (66.1% and 95.8%, respectively) compared to those in patients who exhibited PD (25.1% and 16.5%, respectively). Conclusions: Interim analysis of phase I study showed that YBL-006 is well tolerated and preliminary biomarker analysis showed that the TMB, and intratumoral TIL infiltration are potentially related to the response to YBL-006. Clinical trial information: NCT04450901.

Noninvasive evaluation of tumor immune microenvironment in patients with clear cell renal cell carcinoma using metabolic parameter from preoperative 2-[18F]FDG PET/CT.

Nowadays, it is necessary to explore effective biomarkers associated with tumor immune microenvironment (TIME) noninvasively. Here, we investigated whether the metabolic parameter from preoperative 2-[18F]FDG PET/CT could provide information related to TIME in patients with clear cell renal cell carcinoma (ccRCC). Ninety patients with newly diagnosed ccRCC who underwent 2-[18F]FDG PET/CT prior to surgery were retrospectively reviewed. The immunological features included tumor-infiltrating lymphocytes (TILs) density, programmed death-ligand 1 (PD-L1) expression, and tumor immune microenvironment types (TIMTs). TIMTs were classified as TIMT I (positive PD-L1 and high TILs), TIMT II (negative PD-L1 and low TILs), TIMT III (positive PD-L1 and low TILs), and TIMT IV (negative PD-L1 and high TILs). The relationship between maximum standardized uptake value (SUVmax) in the primary lesion from 2-[18F]FDG PET/CT and immunological features was analyzed. Cox proportional hazards analyses were performed to identify the prognostic factors for disease-free survival (DFS) after nephrectomy. Tumors with high TILs infiltration showed remarkable correlation with elevated SUVmax and aggressive clinicopathological characteristics, such as high World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade. PD-L1 expression on tumor cells was positively associated with WHO/ISUP grade and negatively correlated with body mass index (BMI). However, no correlation was observed between SUVmax and PD-L1 expression, regardless of its spatial tissue distribution. SUVmax of TIMT I and IV was higher than that of TIMT II, but there was remarkable difference merely between TIMT II and IV. In multivariate analysis, SUVmax (P = 0.022, HR 3.120, 95% CI 1.175-8.284) and WHO/ISUP grade (P = 0.046, HR 2.613, 95% CI 1.017-6.710) were the significant prognostic factors for DFS. Six cases (16.2%) with normal SUVmax showed disease progression, while 25 cases (71.4%) with elevated SUVmax experienced disease progression. Conversely, the immunological features held no prognostic value. Our findings demonstrated that 2-[18F]FDG PET/CT could provide metabolic information of TIME for ccRCC patients and develop image-guided therapeutic strategies accordingly. Patients with elevated preoperative SUVmax should be seriously considered, and perioperative immunotherapy might be beneficial for them.

CXCR2 Levels Correlate with Immune Infiltration and a Better Prognosis of Triple-Negative Breast Cancers.

Simple SummaryTumor microenvironment is critical for cancer progression. The role of the chemokine receptors in breast cancers is still under investigation. The aim of this study was to focus on a retrospective cohort of triple-negative breast cancers (TNBCs) and analyze the involvement of CXCR2 and its link with immune infiltration and immune checkpoint markers. High densities of CXCR2-positive cells were associated with high-grade tumors. Higher quantities of CXCR2-positive cells were correlated with elevated density of tumor-infiltrating lymphocytes (TILs), CD8+ cytotoxic lymphocytes, expression of PD-L1 by tumor and stromal cells and of PD-1 by stromal cells. In univariate analysis, low levels of CXCR2 were correlated with poor OS and RFS. In multivariate analysis, low levels of CXCR2 were associated with poor OS. Overall, our data highlight the potential beneficial association of high levels of CXCR2 with a subgroup of TNBC patients characterized by a better prognosis.Chemokines and their receptors are key players in breast cancer progression and outcome. Previous studies have shown that the chemokine receptor CXCR2 was expressed at higher levels by cells of the tumor microenvironment in triple-negative breast cancers (TNBCs). The aim of this study was to focus our attention on a retrospective cohort of 290 TNBC cases and analyze the involvement of CXCR2, CD11b (a marker of granulocytes) and CD66b (a marker of neutrophils) and their link with immune infiltration and immune checkpoint markers. We report that high densities of CXCR2-, CD11b- and CD66b-positive cells were associated with high-grade tumors. Moreover, molecular apocrine TNBCs, defined here as tumors that express both AR and FOXA1 biomarkers, exhibited low levels of CXCR2 and CD11b. High CXCR2 and CD11b levels were correlated with elevated density of tumor-infiltrating lymphocytes (TILs), CD8+ cytotoxic lymphocytes, expression of PD-L1 by tumor and stromal cells and of PD-1 by stromal cells. On the other hand, CD66b levels were associated only with CD8+, stromal PD-L1 and PD-1 expression. In univariate analysis, low levels of CXCR2 were correlated with poor OS and RFS. In multivariate analysis, low levels of CXCR2 were associated with poor OS. Finally, in TNBC treated with adjuvant chemotherapy, CXCR2 density was associated with longer RFS. Overall, our data highlight the potential beneficial association of high levels of CXCR2 with a subgroup of TNBC patients characterized by a better prognosis.

Characterization of Immune Cell Subsets of Tumor Infiltrating Lymphocytes in Brain Metastases.

Simple SummaryBrain metastases arising from breast cancers, occur in about 20% of women with a poor-survival outcome. Unfortunately, most patients survive only up to eighteen months from diagnosis. Therefore, there is an urgent need to understand how these cancers survive in the brain. It is thought that the immune cells in the brain, together with brain resident cells, may provide a favorable environment for cancer growth. However, this is not very well understood at this point. We aimed to profile the cells found in these tumors, focusing on five different cell types based on the marker expressed by them. Our results indicate that certain molecules contained within the cancer and the surrounding environment are associated with poor survival. This suggests that these molecules might be important in brain metastasis. This finding is a step towards our understanding of how some patients with brain metastasis survive longer than others.The heterogeneity of tumor infiltrating lymphocytes (TILs) is not well characterized in brain metastasis. To address this, we performed a targeted analysis of immune-cell subsets in brain metastasis tissues to test immunosuppressive routes involved in brain metastasis. We performed multiplex immunofluorescence (mIF), using commercially available validated antibodies on formalin-fixed paraffin embedded whole sections. We quantitated the subsets of immune-cells utilizing a targeted panel of proteins including PanCK, CD8, CD4, VISTA and IBA-1, and analyzed an average of 15,000 cells per sample. Classifying tumors as either high (>30%) or low (<30%) TILs, we found that increased TILs density correlated with survival. Phenotyping these TILs we found tumors with low TILs had significantly higher expression of the immune-checkpoint molecule VISTA in tumor cells (p < 0.01) as well as in their microenvironment (p < 0.001). Contrastingly, the tumors with high TILs displayed higher levels of microglia, as measured by IBA-1 expression. Low TILs-tumors displayed CD8+ T-cells that co-express VISTA (p < 0.01) significantly more compared to high TILs group, where CD8+cells significantly co-express IBA-11 (p < 0.05). These results were supported by RNA analysis of a publicly available, independent cohort. Our work contributes to a growing understanding of the immune surveillance escape routes active in brain metastasis.

Immune Cell Infiltrates and Neutrophil-to-Lymphocyte Ratio in Relation to Response to Chemotherapy and Prognosis in Laryngeal and Hypopharyngeal Squamous Cell Carcinomas.

Simple SummaryThe role of the immune response to cancer is of increasing importance, with a determining role in the response to the treatments and prognosis of patients. In this work, we studied whether the immune response (local and systemic) can influence the treatment response and prognosis of patients with laryngeal and hypopharyngeal carcinoma receiving induction chemotherapy (ICT). We observed that the relationship between neutrophils and lymphocytes (NLR) in peripheral blood and PD-L1 expression in the tumor is related to ICT response and patient prognosis. The identification of new biomarkers related to the immune response may allow a better selection of treatments and the identification of potential therapeutic targets.Our goal was to assess the correlation of immune parameters with the response to induction chemotherapy (ICT) in head and neck squamous cell carcinoma (HNSCC) patients. Pretreatment biopsies from 64 patients with HNSCC that received ICT were assessed for PD-L1 protein expression and density of CD8+ and FOXP3+ tumor infiltrating lymphocytes (TIL). In addition, the neutrophil-to-lymphocyte ratio (NLR) was calculated from pretreatment whole blood counts. In total, 55% of cases exhibited PD-L1 combined proportion score (CPS) positivity (≥1% stained cells). PD-L1 CPS positivity correlated with a high density of both CD8+ (p = 0.01) and FOXP3+ (p < 0.001) TILs. There was no correlation between PD-L1 expression or TIL density and NLR values. In univariate analyses, the absence of PD-L1 CPS expression (p = 0.042) and a high NLR (p = 0.034) were significantly correlated with response to ICT. Neither CD8+ TIL (p = 0.99) nor FOXP3+ TIL densities (p = 0.71) were associated with response to ICT. In multivariate analysis, only a high NLR was associated with response to ICT (HR = 4.06, 95% CI = 1.06–15.5, p = 0.04). In addition, a high NLR was also independently associated with lower disease-specific (p = 0.03) and overall survival rates (p = 0.04), particularly in the subset of patients who received definitive surgical treatment. These results suggest that NLR could emerge as a predictive biomarker of response to ICT.

Kynurenine/Tryptophan Ratio as a Potential Blood-Based Biomarker in Non-Small Cell Lung Cancer.

The enzyme indoleamine 2,3-dioxygenase 1 (IDO1) degrade tryptophan (Trp) into kynurenine (Kyn) at the initial step of an enzymatic pathway affecting T cell proliferation. IDO1 is highly expressed in various cancer types and associated with poor prognosis. Nevertheless, the serum Kyn/Trp concentration ratio has been suggested as a marker of cancer-associated immune suppression. We measured Kyn and Trp in blood samples of a wide cohort of non-small-cell lung cancer (NSCLC) patients, before they underwent surgery, and analyzed possible correlations of the Kyn/Trp ratio with either IDO1 expression or clinical–pathological parameters. Low Kyn/Trp significantly correlated with low IDO1 expression and never-smoker patients; while high Kyn/Trp was significantly associated with older (≥68 years) patients, advanced tumor stage, and squamous cell carcinoma (Sqcc), rather than the adenocarcinoma (Adc) histotype. Moreover, high Kyn/Trp was associated, among the Adc group, with higher tumor stages (II and III), and, among the Sqcc group, with a high density of tumor-infiltrating lymphocytes. A trend correlating the high Kyn/Trp ratio with the probability of recurrences from NSCLC was also found. In conclusion, high serum Kyn/Trp ratio, associated with clinical and histopathological parameters, may serve as a serum biomarker to optimize risk stratification and therapy of NSCLC patients.

ASO Visual Abstract: Systemic Inflammatory Markers Combined with Tumor-Infiltrating Lymphocyte Density for the Improved Prediction of Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer

ASO Visual Abstract: Systemic Inflammatory Markers Combined with Tumor-Infiltrating Lymphocyte Density for the Improved Prediction of Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer

Systemic Inflammatory Markers Combined with Tumor-Infiltrating Lymphocyte Density for the Improved Prediction of Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer.

Previous studies have reported the utility of systemic inflammatory markers and CD8+ tumor-infiltrating lymphocyte (TIL) separately in predicting response to chemoradiotherapy (CRT) in rectal cancer; however, the efficacy of combining these markers remains unclear. This study aimed to elucidate the predictive efficacy of systemic inflammatory markers combined with CD8+ TIL density on response to neoadjuvant CRT in locally advanced rectal cancer. Ten systemic inflammatory markers and CD8+ TIL density were assessed in 267 patients with rectal cancer using pretreatment clinical data and biopsy samples. Response to CRT was determined using the Dworak tumor regression grade (TRG), with good responders classified as TRG3-4. Receiver operating characteristic curve analysis showed high areas under the curve for the lymphocyte-to-C-reactive protein ratio (LCR) and neutrophil×monocyte (N×M) value (0.58 and 0.62, respectively). In the multivariate analysis, LCR, N×M value, and CD8+ TIL density were independently associated with good responders (p=0.016, 0.005, and 0.002, respectively). Stratified analysis with these three markers showed a positive correlation between TRG3-4 ratio and the number of positive predictive factors (8.2%, 20.0%, 34.2%, and 59.1% in patients with 0, 1, 2, and 3 predictors, respectively). Overall and disease-free survival were significantly worse in patients with zero factors present compared with those with one to three factors present. LCR, N×M value, and CD8+ TIL density are independently associated with response to CRT. Assessing local TIL density along with systemic inflammatory markers may be useful for selecting a multimodal neoadjuvant approach in rectal cancer therapy.

ASO Author Reflections: Combinations of Systemic Inflammatory Markers and CD8+ Tumor-infiltrating Lymphocyte Density: Predictive Utility for Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer.

ASO Author Reflections: Combinations of Systemic Inflammatory Markers and CD8+ Tumor-infiltrating Lymphocyte Density: Predictive Utility for Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer.

Clinical Significance of Tumor Microenvironment in Acral Melanoma: A Large Single-Institution Study of Caucasians.

Background: The presence of tumor-infiltrating lymphocytes (TILs) in many studies is associated with a better prognosis in melanoma patients. Programmed death-ligand 1 (PD-L1) expression has a significant value in predicting several cancers, but its role in melanoma remains ambiguous. The study aims to report a comprehensive analysis of TILs characteristics and their impact on survival in primary acral melanoma (AM). Methods: Clinical and pathological features and survival outcomes were investigated in 70 patients with AM. Immunohistochemical quantitative analysis of TILs, including expression of CD4, CD8, FOXP3, PD-1, and PD-L1, on melanoma cells was performed. Results: Kaplan-Meier analysis showed significant differences in overall survival (OS) for CD4+ (p = 0.021), CD8+ (p = 0.037), FOXP3+ (p = 0.007), and TILs density (p = 0.043). In univariate analysis of immunohistochemical features, FOXP3, CD4, CD8, PD-1, and Melanoma Institute of Australia (MIA) grading TILs (grade, density, and distribution) were correlated with survival. The higher density of FOXP3-positive cells was an independent factor associated with better survival. Conclusions: High TILs content (classed as brisk Clark scale and marked/diffuse TILs MIA grade) regardless of its immunophenotype was associated with better survival outcomes in AM. PD-L1 expression on tumor cells did not influence OS and was independent of clinical and pathological characteristics. We demonstrated that TILs are significant biomarkers in sentinel lymph node status prediction.

POLE and Mismatch Repair Status, Checkpoint Proteins and Tumor-Infiltrating Lymphocytes in Combination, and Tumor Differentiation: Identify Endometrial Cancers for Immunotherapy.

ObjectiveAlthough Polymerase-epsilon (POLE)-mutated and mismatch repair (MMR)-deficient endometrial cancers (ECs) are considered as promising candidates for anti-PD-1/PD-L1 therapy, selecting only these patients may exclude other patients who could potentially respond to this treatment strategy, highlighting the need of additional biomarkers for better patient selection. This study aims to evaluate potential predictive biomarkers for anti-PD-1/PD-L1 therapy in addition to POLE mutation (POLEm) and MMR deficiency (MMRd).MethodsWe performed next generation sequencing for POLE from 202 ECs, and immunohistochemistry for MLH1, MSH2, MSH6, PMS2, CD3, CD8, PD-1 and PD-L1 on full-section slides from these ECs. We assessed the association of POLEm and MMRd with clinicopathologic features, expression of check point proteins, and density of tumor-infiltrating lymphocytes (TILs). Prognostic impact of these immune markers was also evaluated.ResultsPOLEm, MMRd and high-grade tumors exhibited elevated level of TILs. Increased expression of PD-1 and PD-L1 was observed in MMRd and high-grade ECs. A subgroup of MMR proficient ECs also harbored increased density of TILs, and positive expression of PD-1 and PD-L1. In addition, negative expression of checkpoint proteins and high density of TILs in combination was associated with good prognosis.ConclusionsCandidates for PD-1 blockade may extend beyond POLEm and MMRd ECs, additional factors such as tumor grade, and combination of TILs levels and expression of checkpoint proteins may need to be considered for better patient selection.

The density of tumor-infiltrating lymphocytes and prognosis in resectable hepatocellular carcinoma: a two-phase study.

Aim: Previous studies have focused on the subpopulations of tumor-infiltrating lymphocytes (TILs) in tumors. This study focuses only on the concentration of TILs in the tumor irrespective of type and elucidates its prognostic value.Methods: We used 315 HCC patients as the discovery phase and another 343 HCC patients as the validation phase. By following the standardized guideline, density of TILs were categorized into low (TILs < 10%), intermediate (10% ≦ TILs < 50%), and high (TILs ≧ 50%) levels. Associations of TILs with prognostic, immune-related, and genetic variables were examined.Results: We observed a dose-response relation of TILs with overall survival (intermediate: HR, 0.58; 95% confidence interval (CI), 0.36-0.93; high: HR, 0.37; 95% CI, 0.15-0.93) and disease-free survival (intermediate: HR, 0.35; 95% CI, 0.22-0.58; high: HR, 0.23; 95% CI, 0.09-0.58). The prognostic value of TILs was validated in the TCGA set. Mutation burden or the number of neoantigens were not associated with TILs intensity. However, hepatitis B or C virus infection patients had higher TILs intensity in the para-tumor tissue.Conclusions: The TILs intensity was associated with patients' survival. If confirmed, this would suggest that clinical routine assessment of TILs could provide prognostic information in HCC.

From the Editor’s Desk...

From the Editor’s Desk...

LAG-3 expression in the inflammatory microenvironment of glioma

PurposeImmune modulatory therapies including immune checkpoint inhibitors have so far failed to result in clinically meaningful efficacy in glioma. We aimed to investigate lymphocyte activation gene 3 (LAG-3), an inhibitory receptor on immune cells and target of second-generation immune checkpoint inhibitors, in glioma.Methods97 patients with diffuse glioma (68 with glioblastoma, 29 with WHO grade II-III glioma) were identified from the Neuro-Biobank of the Medical University of Vienna. LAG-3 expression in the inflammatory microenvironment was assessed by immunohistochemistry (monoclonal anti-LAG-3 antibody, clone 17B4) and correlated to CD3+ , CD8+ , CD20+ and PD-1+ tumor-infiltrating lymphocytes (TILs) and PD-L1 expression on tumor cells.ResultsLAG-3+ TILs could be observed in 10/97 (10.3%) IDH-wildtype samples and in none of the included IDH-mutant glioma samples (p = 0.057). Further, LAG-3+ TILs were only observed in WHO grade IV glioblastoma, while none of the investigated WHO grade II–III glioma presented with LAG-3+ TILs (p = 0.03). No association of O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation and presence of LAG-3+ TILs was observed (p = 0.726). LAG-3 expression was associated with the presence of CD3+ (p = 0.029), CD8+ (p = 0.001), PD-1+ (p < 0.001) TILs and PD-L1+ tumor cells (p = 0.021), respectively. No association of overall survival with LAG-3+ TIL infiltration was evident (median OS 9.9 vs. 14.2 months, p = 0.95).ConclusionsLAG-3 is only rarely expressed on TILs in IDH-wildtype glioma and associated with active inflammatory milieu as defined by higher TIL density. Immune microenvironment diversity should be considered in the design of future immunotherapy trials in glioma.

Nomograms to Predict the Density of Tumor-Infiltrating Lymphocytes in Patients With High-Grade Serous Ovarian Cancer.

BackgroundTumor-infiltrating lymphocytes (TILs) have important roles in predicting tumor therapeutic responses and progression, however, the method of evaluating TILs is complicated. We attempted to explore the association of TILs with clinicopathological characteristics and blood indicators, and to develop nomograms to predict the density of TILs in patients with high-grade serous ovarian cancer (HGSOC).MethodsThe clinical profiles of 197 consecutive postoperative HGSOC patients were retrospectively analyzed. Tumor tissues and matched normal fallopian tubes were immunostained for CD3+, CD8+, and CD4+ T cells on corresponding tissue microarrays and the numbers of TILs were counted using the NIH ImageJ software. The patients were classified into low- or high-density groups for each marker (CD3, CD4, CD8). The associations of the investigated TILs to clinicopathological characteristics and blood indicators were assessed and the related predictors for densities of TILs were used to develop nomograms; which were then further evaluated using the C-index, receiver operating characteristic (ROC) curves and calibration plots.ResultsMenopausal status, estrogen receptor (ER), Ki-67 index, white blood cell (WBC), platelets (PLT), lactate dehydrogenase (LDH), and carbohydrate antigen 153 (CA153) had significant association with densities of tumor-infiltrating CD3+, CD8+, or CD4+ T cells. The calibration curves of the CD3+ (C-index = 0.748), CD8+ (C-index = 0.683) and CD4+ TILs nomogram (C-index = 0.759) demonstrated excellent agreement between predictions and actual observations. ROC curves of internal validation indicated good discrimination for the CD8+ TILs nomogram [area under the curve (AUC) = 0.659, 95% CI 0.582–0.736] and encouraging performance for the CD3+ (AUC= 0.708, 95% CI 0.636–0.781) and CD4+ TILs nomogram (AUC = 0.730, 95% CI 0.659–0.801).ConclusionMenopausal status, ER, Ki-67 index, WBC, PLT, LDH, and CA153 could reflect the densities of T cells in the tumor microenvironment. Novel nomograms are conducive to monitor the immune status of patients with HGSOC and help doctors to formulate the appropriate treatment strategies.

Tumor mutation burden and immune microenvironment analysis of urothelial carcinoma.

494 Background: Tumor mutation burden (TMB) has been established as a biomarker for response to immune therapy and prognosis in various cancers. However, the correlation between TMB and immune microenvironment remains unwell studied, especially in urothelial carcinoma. This study was aimed to investigate the relationship between TMB and other immunotherapy related biomarkers, including genetic alterations, APOBEC signature, microsatellite instability (MSI), PD-L1 expression and immune cell infiltration in urothelial carcinoma. Methods: 131 patients with urothelial carcinoma admitted from October 2018 to May 2020 were included. Total DNA was isolated from FFPE or fresh tissues. Mutation profiles, APOBEC signature and MSI scores were obtained by next-generation sequencing based a 642 cancer genes panel assay. PD-L1 expression, CD8+ T-cells and tumor-infiltrating lymphocytes density were evaluated by immunohistochemistry. The correlation was analyzed by Wilcoxon signed-rank test. Results: The mutation landscape showed that TP53 mutation is the most common alterations (n = 64/131, 48.9%), followed by KMT2D alterations (n = 49/131, 37.4%), KDM6A mutations (n = 42/131, 32.1%), MUC17 mutations (n = 42/131, 32.1%). The median TMB was 5.06 Muts/Mb (0-118 Muts/Mb). 2 of 131 patients showed MSI-H, who exhibited a much higher TMB (41, 118 Muts/Mb). Further analysis showed that TMB in the patients with certain gene mutations (such as TP53, KMT2D, KDM6A and MUC17) was significantly higher than those wild type ones (p &lt; 0.05). Meanwhile, the high APOBEC-enrichment group has a higher TMB than the low APOBEC-enrichment group (p = 0.045). Furthermore,we observed that the patients with a higher PD-L1 expression (n = 28/131, 21.4%, at a combined positive score cut-off value of 10) also showed a significantly higher TMB (p = 0.016), and TMB in the patients with higher density of CD8+ T-cells (n = 42/131, 32.1%, at a cut-off value of 5%) was also significantly higher than that of the group with lower density of CD8+ T-cells (p = 0.039). Conclusions: This study provides new insights into the correlation between the TMB and the immune microenvironment in urothelial carcinoma. The result may be a reference to immunotherapy.

Abstract PS4-38: Association of tumor infiltrating lymphocytes (TILs) density and PD-L1 expression with pembrolizumab (P) plus gemcitabine (Gem) efficacy in patients with HER2-negative advanced breast cancer (ABC) from the GEICAM/2015-04 (PANGEA-Breast) study

Abstract Background Immune cells (ICs) infiltration and immune checkpoints have been shown to be important for BC patients’ (pts) prognosis and response to immunotherapy. We aimed to analyze the relation between TILs prevalence and PD-L1 expression with efficacy to an immunostimulatory combination with P and Gem in ABC HER2-negative pts previously treated with ≤4 chemotherapy and/or ≥2 hormone therapy lines from the PANGEA-Breast trial (NCT03025880). Methods Pre-treatment (ttm) metastatic BC samples were assessed for TILs density [% of occupied stromal area upon H&amp;E staining] and for PD-L1 immunohistochemistry expression using monoclonal anti-PD-L1 antibody clone 22C3 (Merck) by calculating ICs score (% of positive infiltrated ICs) and combined positive score [CPS; PD-L1 stained cells (tumor cells, lymphocytes, macrophages) divided by total viable tumor cells, multiplied by 100]. Cut-offs ≥5%, ≥10%, ≥30% were explored for TILs. PD-L1 scores were considered positive if ≥1%. Cut-offs (≥5%, ≥20%, ≥50%) were additionally assessed for PD-L1 as CPS. Logistic regression models were used to evaluate association between TILs density and PD-L1 expression with ttm efficacy in terms of Objective Response Rate [ORR; Complete + Partial Response (CR + PR)], Clinical Benefit Rate [CBR; CR + PR + Stable Disease ≥24 weeks] and Progression Free Survival (PFS), according to RECIST v1.1. Results Thirty-six pts were included, 58% had triple negative BC and 98% ECOG score ≤1. Median number of prior ttm lines was 4. ORR and CBR were 15.2% and 17%, respectively; median PFS was 3.1 months. TILs and PD-L1 were evaluated in 30 and 29 pts, respectively. No association was found between TILs density and ttm efficacy in terms of ORR, CBR and PFS. Analysis of PD-L1 ICs score did not reveal any significant association with ORR, CBR or PFS. However, pts with negative PD-L1 expression by CPS (&amp;lt;1%) had a significantly prolonged PFS [p-value=0.031; HR 0.39 (95%CI 0.16; 0.95)], not maintained at CPS &amp;lt;20% cut-off [p-value=0.062; HR 0.42 (95%CI 0.17; 1.08)]. Conclusions Our findings support that: 1) P plus Gem ttm in heavily pre-treated HER2-negative ABC pts obtains a modest ORR of 15.2%; 2) TILs density and PD-L1 expression in ICs does not predict its benefit; 3) PD-L1 in tumor cells scored as CPS impacts in worse outcome (PFS) but not in ORR, suggesting an eventual prognostic role in this population; 4) no long-term responders were observed with P plus Gem in this trial. Citation Format: Luis De la Cruz, María Gion, Josefina Cruz, Jose Luis Alonso, Vanesa Quiroga, Fernando Moreno, Marta Santisteban, Raquel Andrés, Esther Holgado, Natalia Palazón, Luz Milva Rodríguez, Asunción Soto, Javier Cortés, Alfonso Cortés, Manuel Ramos, Maribel Casas, Massimo Chiesa, Susana Bezares, Rosalía Caballero, Federico Rojo. Association of tumor infiltrating lymphocytes (TILs) density and PD-L1 expression with pembrolizumab (P) plus gemcitabine (Gem) efficacy in patients with HER2-negative advanced breast cancer (ABC) from the GEICAM/2015-04 (PANGEA-Breast) study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS4-38.

Abstract PS4-37: A pro-tumorigenic mechanism of M2 tumor-associated macrophages (TAM) in triple-negative breast cancer

Abstract Introduction:Triple-Negative Breast Cancer (TNBC) comprises approximately 30% of all breast cancers in Indian women. Given their aggressive nature, TNBCs have high rates of systemic metastasis and mortality with only chemotherapy available for treatment. The success of immunotherapy in solid tumors has raised the hope for their utility in TNBCs as well. But only a subset of patients have a clinical response to check-point inhibitors. The cellular and molecular mechanisms that mediate the immunological response or tolerance are just beginning to be understood. Compared to ER/PR+ breast cancer, TNBC features a unique tumor microenvironment (TME) characterized by a large number of tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs). The density of TILs in and of themselves do not accurately predict response to neoadjuvant chemotherapy or survival. M2 tumor-associated macrophages (M2-TAMs) have been reported to associate with solid tumors to facilitate epithelial to mesenchymal transition (EMT), tumor invasiveness, metastasis, and resistance to therapy. In this study, we have characterized presence of M2-TAM in the TNBC immune environment by examining expression of several biomarkers. Methods:Surgically excised tumor specimens from 88 Indian women with TNBC were accessed from the longitudinal observational series of SJNAHS tissue bank under IERB approved protocols and assayed on nCounter® PanCancer Immune Profiling Panel which comprised of 740 genes and characterises 14 different immune cell types. Transcriptome analysis using Non-negative Matrix factorization (NMF) based unsupervised clustering was done to arrive at stable subtypes characterized by different tumour microenvironments within TNBC. CIEBERSORT tool was used to analyse for distribution of cell types. Identification of macrophages was done by Immunohistochemistry (IHC) for CD68 and CD163 markers in TNBCs and a control group of ER+HER2-.Results:NMF analysis with an enriched immune gene signature of 111 genes, yielded 3 subtypes (ST) (37%, 27% and 36% with relative proportions of ST1, ST2 and ST3) within the TNBC. The three subtypes had distinct survival patterns with ST1 having the best prognosis with enriched TH1 gene signature and ST3 had poorest (log rank p=0.5). On application of this gene signature to TNBC groups in METABRIC and TCGA data, similar pattern emerged with a significant survival pattern of ST 3 having the poorest outcome (p=0.005). A closer examination of ST 3 revealed a signature enriched for M2 macrophages also known as TAM. Immunohistochemistry for Pan macrophage marker CD68 and an M2 specific marker CD163 between TNBC and ER/PR+ revealed difference in the two groups was significantly different (Mann Whitney p=0.03), with TNBC exhibiting 2.4 fold higher expression of CD163. CD 68, was enriched in ST2 and ST3. CD163 which is an M2 specific marker was highest in ST3 as compared to ST 1&amp; 2 (p=0.04). This group also correlated with signal molecules secreted by macrophages containing growth factors, cytokines and chemokines, such as TGF-β, VEGF, IL-10 and CXCL and interleukins like IL4 and IL6 suggestive of TAM recruitment and polarization. It is likely that the TAM enriched subgroup is likely to be unresponsive to PD1/PDL1 inhibitors but could be targeted by novel therapeutic strategies to directly target M2-TAM. In vitro and In vivo analysis to target M2-TAM to evaluate the response to these therapeutic compounds in cell lines as well as a mouse syngeneic model is underway.Conclusions and future directions: As a cell type within the tumor microenvironment, that promotes invasion, M2-TAMs makes an ideal therapeutic target in TNBC. In addition, this sub-type lends itself to easy identification by a simple IHC assay. Citation Format: Aruna Korlimarla, Jyothi Prabhu, Chantirika Ragulan, Gnanapriya Shivakumar, Krisha Desai, Maggie Cheang, Srinath BS, Ravi Diwakar, Sandhya Apachu, Rekha Kumar, TS Sridhar, Savitha RajaRajan, Rohini Kaluve, Annie Alexander, Anguraj Sadanandam. A pro-tumorigenic mechanism of M2 tumor-associated macrophages (TAM) in triple-negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS4-37.

Tumor mutational burden and immune infiltrates in renal cell carcinoma and matched brain metastases

BackgroundTumor mutational burden (TMB) and density of tumor-infiltrating lymphocytes (TIL) have been postulated as predictive biomarkers for immunotherapy. Therefore, we investigated the concordance of TMB and TIL of primary/extracranial renal cell carcinoma (RCC) specimens and matched brain metastases (BM).Patients and methodsTwenty specimens from 10 patients were retrieved from the Vienna Brain Metastasis Registry (6/10 primary tumor, 4/10 lung metastasis, 10/10 matched BM). TMB was assessed using the TruSight Oncology 500 gene panel with libraries sequenced on a NextSeq instrument. TIL subsets (CD3+, CD8+, CD45RO+, FOXP3+, PD-L1+) were investigated using immunohistochemistry (Ventana Benchmark Ultra system) and automated tissue analysis (Definiens software).ResultsNo significant difference in TMB, CD3+, CD8+, CD45RO+, FOXP3+ or PD-L1+ expression was observed between extracranial and matched intracranial specimens (P > 0.05). Higher CD8+ TIL (P = 0.053) and CD45RO+ TIL (P = 0.030) densities in the primary tumor compared with the intracranial samples were observed in specimens collected after exposure to systemic treatment. Neither extracranial sample origin (lung metastasis versus primary RCC) nor extracranial disease status at BM diagnosis (progressive versus stable disease) were significantly associated with TMB or TIL densities in extracranial and intracranial samples (P > 0.05). No significant correlation was found between the median differences of TMB or TIL densities from extracranial to intracranial samples and BM-free survival.ConclusionThe comparable immunological microenvironment of extra- and intracranial tumor samples in our study underscores the immunological activation also in BM from RCC, and therefore, supports the development of immune modulatory treatments also in patients with brain metastatic RCC.

Clinicopathological Correlates of γδ T Cell Infiltration in Triple-Negative Breast Cancer.

Simple SummaryThe prognostic impact of the different tumor-infiltrating lymphocyte (TIL) subpopulations remains debated in solid cancers. We investigated the clinicopathological correlates and prognostic impact of TILs, particularly of γδ T cells, in 162 triple-negative breast cancer (TNBC) patients. A high γδ T cell density was significantly associated with younger age, higher tumor histological grade, adjuvant chemotherapy, BRCA1 promoter methylation, TIL density, and PD-L1 and PD-1 expression. In multivariate analyses, γδ T cell infiltration was an independent prognostic factor. However, this prognostic impact varied according to the tumor PIK3CA mutational status. High γδ T cell infiltration was associated with better survival in patients with PIK3CA wild-type tumors, without significant difference in the PIK3CA-mutated tumor subgroup. Altogether, these data suggest that high γδ T cell infiltrate is correlated with immune infiltration and might represent a prognostic tool in TNBC patients.The prognostic impact of the different tumor-infiltrating lymphocyte (TIL) subpopulations in solid cancers is still debated. Here, we investigated the clinicopathological correlates and prognostic impact of TILs, particularly of γδ T cells, in 162 patients with triple-negative breast cancer (TNBC). A high γδ T cell density (>6.625 γδ T cells/mm2) was associated with younger age (p = 0.008), higher tumor histological grade (p = 0.002), adjuvant chemotherapy (p = 0.010), BRCA1 promoter methylation (p = 0.010), TIL density (p < 0.001), and PD-L1 (p < 0.001) and PD-1 expression (p = 0.040). In multivariate analyses, γδ T cell infiltration (cutoff = 6.625 γδ T cells/mm2) was an independent prognostic factor (5-year relapse-free survival: 63.3% vs. 89.8%, p = 0.027; 5-year overall survival: 73.8% vs. 89.9%, p = 0.031, for low vs. high infiltration). This prognostic impact varied according to the tumor PIK3CA mutational status. High γδ T cell infiltration was associated with better survival in patients with PIK3CA wild-type tumors, but the difference was not significant in the subgroup with PIK3CA-mutated tumors. Altogether, these data suggest that high γδ T cell infiltrate is correlated with immune infiltration and might represent a candidate prognostic tool in patients with TNBC.