Abundance Of Tumor-infiltrating Lymphocytes Research Articles

Tumor mutation burden and immunological, genomic, and clinicopathological factors as biomarkers for checkpoint inhibitor treatment of patients with non-small-cell lung cancer.

Cancer treatment using immune checkpoint inhibitors is widely used, although biomarkers predictive of response are not well established. However, both the expressions of programmed cell death ligand 1 (PD-L1) and the tumor mutation burden (TMB) hold promise as such biomarkers for immune checkpoint inhibitors; however, its characteristics and clinical and immunological impacts have not been fully analyzed. We, therefore, evaluated the clinical and immunological parameters related to TMB to identify potential new biomarkers. We enrolled 92 patients with non-small-cell lung cancer who underwent surgery at Fukushima Medical University Hospital from 2013 to 2016. TMB of individual tumors was calculated by whole-exome sequencing analysis. Major cancer-related gene mutations were evaluated using panel sequencing. Expression of PD-L1 and abundance of tumor-infiltrating lymphocytes were evaluated by immunohistochemistry using surgical samples. The median TMB value was 60. TMB was significantly higher in men, current or former smokers, and in patients with squamous cell carcinoma, tumor size ≥ 2.8cm, wild-type EGFR, TP53 gene mutation-positive status, and cyclin-dependent kinase-inhibitor gene 2A mutation-positive status. According to multivariate analysis, TMB was significantly associated with EGFR gene mutation-negative status (p = 0.0111) and TP53 gene mutation-positive status (p = 0.0425). If TMB is identified as a robust biomarker for immune checkpoint inhibitor administration, analysis of TP53 and EGFR mutations may provide a relatively rapid and easy proxy for predicting TMB.

Clinicopathological values of PD-L1 expression in HER2-positive breast cancer

Several ongoing clinical trials are investigating the use of immuno-targeting therapy with programmed cell death protein-1 and programmed death-ligand 1 (PD-L1) inhibitors for triple-negative breast cancer. However, the role of PD-L1 expression in HER2-positive breast cancer remains unclear. We investigated the clinicopathological utility of PD-L1 expression in HER2-positive breast cancer. Cohort A included 248 patients with invasive breast cancer (all subtypes). Cohort B included 126 HER2-positive patients who received neoadjuvant chemotherapy (NAC) concomitant with trastuzumab. The relationship of PD-L1 expression on the cancer cells with clinicopathological factors including pathological complete response (pCR) and prognosis was investigated. In cohort A, 8.1% patients were PD-L1-positive; PD-L1 positivity showed a correlation with high degree of tumor-infiltrating lymphocytes (TILs), estrogen receptor negativity, progesterone receptor negativity, and high histological grade. In cohort B, 17.5% patients were PD-L1-positive; PD-L1 positivity showed a significant correlation with high degree of TILs and high abundance of CD8-positive TILs. The pCR rates were related to TILs and PD-L1 expression. Among PD-L1-negative patients, high CD8-positive TILs were associated with significantly better prognosis. In conclusion, 17.5% of HER2-positive type patients were PD-L1-positive. PD-L1 expression was associated with response to NAC with trastuzumab in patients with HER2-positive breast cancer.

PD-L1 Expression in Endometrial Carcinoma Cells and Intratumoral Immune Cells: Differences Across Histologic and TCGA-based Molecular Subgroups.

Programmed death-ligand 1 (PD-L1) is a biomarker that may predict the response to anti-programmed death 1/PD-L1 immunotherapy. We evaluated the expression of PD-L1 in carcinoma cells (Ca) and immune cells (ICs) across histopathologic and The Cancer Genome Atlas (TCGA) molecular subgroups of endometrial carcinoma (EC). Our study included 842 patients with EC. Direct sequencing of polymerase epsilon (POLE) exonuclease domain hot spots and conventional immunohistochemistry (MLH1, PMS2, MSH2, MSH6, p53) were conducted to identify TCGA classification-based molecular subgroups of EC: POLE-mutated, mismatch repair deficient, no specific molecular profile, and p53 aberrant. Multiplex immunohistochemistry was performed to evaluate PD-L1 expression in Ca and tumor-infiltrating ICs. PD-L1 expression in Ca and in ICs was detected in 8.6% and 27.7% of the cases, respectively. A combined positive score (CPS) was ≥1% in 19.4% of the samples. PD-L1 positivity in Ca and ICs, and CPS correlated with tumor T-cell density (P<0.001). POLE-mutated and mismatch repair-deficient tumors were more likely to present PD-L1-expressing ICs, CPS positivity, and abundant tumor-infiltrating lymphocytes compared with other TCGA subgroups (P<0.001). No differences existed in Ca-PD-L1 expression (P=0.366). Within various histotypes, non-endometrioid carcinomas displayed the highest Ca-PD-L1, ICs, and CPS (P<0.03). Advanced cancers showed more frequent Ca-PD-L1 positivity (P=0.016), and CPS (P=0.029) and IC≥1% (P=0.037) positivity compared with early disease. In conclusion, PD-L1 expression profiles differ between molecular subclasses, histologic subtypes, and disease stage of EC. Prospective studies are needed to explore the predictive value of various PD-L1 scoring systems within the subgroups of EC. CPS presents methodological advantages over cell type-specific scoring systems.

Association of Germline Variants in Natural Killer Cells With Tumor Immune Microenvironment Subtypes, Tumor-Infiltrating Lymphocytes, Immunotherapy Response, Clinical Outcomes, and Cancer Risk

Only a small fraction of patients with cancer receiving immune checkpoint therapy (ICT) respond, which is associated with tumor immune microenvironment (TIME) subtypes and tumor-infiltrating lymphocytes (TILs). To examine whether germline variants of natural killer (NK) cells, a key component of the immune system, are associated with TIME subtypes, the abundance of TILs, response to ICT, clinical outcomes, and cancer risk. This genetic association study explored TIME subtypes and examined the association of the germline genomic information of patients with cancer with TIME subtypes, abundance of TILs, response to ICT, prognosis, and cancer risk. Clinical information, tumor RNA sequencing, and whole-exome sequencing (WES) data of paired normal samples of patients with 13 common cancers (n = 5883) were obtained from the Cancer Genome Atlas. The WES data of individuals with no cancer (n = 4500) were obtained from the database of Genotypes and Phenotypes. Data collection and analysis took place in March 2017. Associations between the number of germline defective genes in NK cells and survival time and the abundance of TILs. Based on tumor RNA sequencing data, tumors were stratified into TIME-rich, TIME-intermediate, and TIME-poor subtypes. Tumors of TIME-rich subtype had more TILs (TIL-NK cells in TIME-rich head and neck squamous cell carcinoma [HNSC] tumors: t = 4.85; 95% CI of the difference, 0.01-0.03; P = 2.19 × 10-6) compared with TIME-intermediate HNSC tumors (t = 3.70; 95% CI of the difference, 0.01-0.03; P < .001), better prognosis (patients with HNSC: hazard ratio, 0.65; 95% CI, 0.41-1.02; P = .054) compared with TIME-intermediate and TIME-poor subtypes, and better ICT response (patients with melanoma: odds ratio [OR], 4.45; 95% CI, 0.99-27.08; P = .04). Patients with TIME-rich tumors had significantly fewer inherited defective genes in NK cells than patients with TIME-intermediate and TIME-poor tumors (patients with HNSC: OR, 0.49; 95% CI, 0.26-1.07; P = .005). Similarly, patients with cancer had significantly more inherited defective genes in NK cells than individuals with no cancer (patients with HNSC: OR, 19.09; 95% CI, 4.30-315.96; P = 6.21 × 10-4). Among 11 of 13 common cancers, the number of heritable defective genes in NK cells was significantly negatively associated with survival (patients with HNSC: hazard ratio, 1.77; 95% CI, 1.18-2.66; P = .005), abundance of TILs (patients with HNSC: R = -0.25; 95% CI, -0.65-2.17; P = 0.02), and response to ICT (patients with melanoma: OR, 4.45; 95% CI, 0.99-27.08; P = .04). These results suggest that individuals who have more inherited defective genes in NK cells had a higher risk of developing cancer and that these inherited defects were associated with TIME subtypes, recruitment of TILs, ICT response, and clinical outcomes. The findings have implications for identifying individuals at risk for developing cancer of many types based on germline variants of NK cells and for improving existing ICT and chimeric antigen receptor-T cell therapy by adoptive transfer of healthy NK cells to patients with TIME-intermediate and TIME-poor tumors.

Identification and validation of novel microenvironment-based immune molecular subgroups of head and neck squamous cell carcinoma: implications for immunotherapy.

Targeting the immune checkpoint pathway has demonstrated antitumor cytotoxicity in treatment-refractory head and neck squamous cell carcinoma (HNSC). To understand the molecular mechanisms underpinning its antitumor response, we characterized the immune landscape of HNSC by their tumor and stromal compartments to identify novel immune molecular subgroups. A training cohort of 522 HNSC samples from the Cancer Genome Atlas profiled by RNA sequencing was analyzed. We separated gene expression patterns from tumor, stromal, and immune cell gene using a non-negative matrix factorization algorithm. We correlated the expression patterns with a set of immune-related gene signatures, potential immune biomarkers, and clinicopathological features. Six independent datasets containing 838 HNSC samples were used for validation. Approximately 40% of HNSCs in the cohort (211/522) were identified to show enriched inflammatory response, enhanced cytolytic activity, and active interferon-γ signaling (all, P < 0.001). We named this new molecular class of tumors the Immune Class. Then we found it contained two distinct microenvironment-based subtypes, characterized by markers of active or exhausted immune response. The Exhausted Immune Class was characterized by enrichment of activated stroma and anti-inflammatory M2 macrophage signatures, WNT/transforming growth factor-β signaling pathway activation and poor survival (all, P < 0.05). An enriched proinflammatory M1 macrophage signature, enhanced cytolytic activity, abundant tumor-infiltrating lymphocytes, high human papillomavirus (HPV) infection, and favorable prognosis were associated with Active Immune Class (all, P < 0.05). The robustness of these immune molecular subgroups was verified in the validation cohorts, and Active Immune Class showed potential response to programmed cell death-1 blockade (P = 0.01). This study revealed a novel Immune Class in HNSC; two subclasses characterized by active or exhausted immune responses were also identified. These findings provide new insights into tailoring immunotherapeutic strategies for different HNSC subgroups.

Pilot evaluation of PD-1 inhibition in metastatic cancer patients with a history of liver transplantation: the Mayo Clinic experience.

Patients with solid organ transplants (SOTs) have been excluded from programmed death protein-1 (PD-1)/programmed death ligand-1 (PD-L1) inhibitor clinical trials due to concern for allograft rejection. The use of immune checkpoint inhibitor therapy remains controversial in transplant patients. A retrospective pilot evaluation was conducted to assess the safety and efficacy of PD-1 inhibitors in patients with liver transplantation (LT). The primary endpoint was the rate of allograft rejection. Secondary endpoints included overall response rate (ORR), progression free survival (PFS) and overall survival (OS). Translational objectives included evaluation of tumor PD-L1, tumor infiltrating lymphocytes (TILs) and allograft PD-L1 expression. Seven metastatic cancer patients with a history of LT who received PD-1 inhibitor therapy were included [hepatocellular carcinoma (HCC), n=5; melanoma, n=2]. Rejection was observed in 2 of 7 patients. When rejection occurs it appears to be an early event with a median time to rejection of 24 days in our cohort. One patient achieved a complete response (CR), 3 patients had progressive disease (PD) and 3 patients discontinued therapy prior to restaging assessments. Two of five patients with available tissue had PD-L1 expression in the allograft and both developed rejection. One of five evaluable patients had abundant TILs. Two of five evaluable patients had PD-L1 tumor staining. The single patient with both abundant TILs and PD-L1 staining obtained a response. The median OS and PFS were 1.1 (0.3-21.1) and 1.8 (0.7-21.1) months, respectively. In this pilot evaluation both preliminary efficacy (1 of 4) and allograft rejection (2 of 7) were exhibited in evaluable patients. Larger, prospective trials are needed to elucidate optimal patient selection.

Characterization of PD-L1 and PD-1 Expression and CD8+ Tumor-infiltrating Lymphocyte in Epstein-Barr Virus-associated Nasopharyngeal Carcinoma.

Immunotherapies that target the programmed death-1/ programmed death-1 ligand (PD-1/PD-L1) immune checkpoint pathway have shown promise in nasopharyngeal carcinoma (NPC) in early phases clinical studies. Here, we evaluated PD-1 and PD-L1 expression and CD8+ tumor-infiltrating lymphocytes (TILs) in NPC patients. Newly diagnosed NPC patients were identified through the institutional database between January 2007 and December 2012. PD-L1 and PD-1 expression, Epstein-Barr virus (EBV) status, and CD8+ TIL numbers were measured in archival tumor samples at diagnosis and their correlations with clinicopathologic features, including survival, were evaluated. A total of 114 NPC patients were analyzed. Most patients (96%) were EBV positive. PD-L1 was expressed in ≥1% of tumor cells (TCs) in 69% of patients, in ≥50% of TCs in 12% of patients, and in ≥5% of either TCs or infiltrating immune cells in 71% of patients. CD8+ TILs were present in tumors from all patients, whereas only 11% of tumors expressed PD-1. There were no correlations between PD-L1 expression and CD8+ TIL abundance, PD-1 expression, or survival. Approximately 70% of EBV-positive NPC expressed PD-L1, but this did not correlate with patient survival or clinicopathologic features. The findings of this study represent the immune biomarker profile of confirmed EBV-associated NPC in an endemic region. Since the current clinical development of immune checkpoint inhibitor for NPC is mostly focusing on an EBV-associated tumor, differences in immune biomarker profiles and EBV status of endemic and nonendemic regions should be further explored.

Expression of programmed cell death ligand 1 and immune checkpoint markers in residual tumors after neoadjuvant chemotherapy for advanced high-grade serous ovarian cancer

ObjectiveTo investigate the prognostic value of the expressions of programmed cell death ligand 1 (PD-L1) and immune checkpoint markers in residual tumors after neoadjuvant chemotherapy (NAC) for advanced high-grade serous ovarian cancer (HGSOC). MethodsWe collected pre- and post-NAC tumor samples from patients with advanced HGSOC between 2006 and 2017. Post-NAC tumor tissue samples were available for immunostaining from 131 patients. The expressions of PD-L1 and immune checkpoint markers were assessed by immunohistochemical staining and the status of tumor-infiltrating lymphocytes (TILs) was also evaluated. We examined whether there are significant associations between protein expression status and patient outcomes and whether significant changes in protein expression levels occurred in response to NAC. ResultsPD-L1 expression in the tumor cells was evaluated in 113 patients, 12 (10.6%) of whom had high PD-L1 expression (≥25%) in post-NAC tissues. However, these high levels were not associated with progression-free survival (PFS; P = 0.348) or overall survival (OS; P = 0.699). Similarly, high stromal TILs [≥50%; n = 16 (15.0%)] among the 107 patients evaluated did not show any significant impact on PFS (P = 0.250) or OS (P = 0.800). Moreover, an abundance of TILs (intraepithelial, CD8+, and Foxp3+) and the expression of immune checkpoint markers (PD-1, ICOS, and LAG-3) in residual tumors did not confer any significant survival benefit. The impact of NAC on PD-L1 expression and stromal TILs varied considerably among individual patients. ConclusionAlthough the expression of PD-L1 and immune checkpoint markers in residual tumors after NAC had no prognostic impact on survival in patients with HGSOC, post-NAC evaluation of these proteins in chemoresistant tumors may help select patients for immunotherapy trials.

Dynamic evaluation of the immune infiltrate and immune function genes as predictive markers for neoadjuvant chemotherapy in hormone receptor positive, HER2 negative breast cancer

ABSTRACTGene expression (GE) signatures and Tumor Infiltrating Lymphocytes (TIL) enumeration are predictive for response to neoadjuvant chemotherapy in HR- and in HER2+ breast cancer, but data are conflicting in HR+/HER2- disease. This study aimed to explore their predictive value in this subset, measured both at baseline and after short exposure to chemotherapy. Specifically, the PROMIX phase 2 trial enrolled patients with locally advanced HER2- BC to receive six cycles of epirubicin and docetaxel, plus bevacizumab during cycles 3–6. Patients underwent tumor biopsies at baseline and after cycle 2 for GE profiling and enumeration of TIL, FOXP3+ T-cells and CD163+ macrophages. An immune related gene module and the quantification of the immune infiltrate were analyzed for association with pathologic complete response (pCR), decrease in tumor size and disease-free survival (DFS). Of the 150 patients enrolled in PROMIX, 113 were HR+/HER2-. Baseline GE and immune cell enumeration data were available from 71 patients, while data after 2 cycles of chemotherapy were available from 41. At baseline, only GE was statistically significantly associated with higher pCR rates (OR 2.29, 95% CI 1.05 – 5.38, p = 0.037) and decrease in tumor size (r = 0.25, p = 0.047). In contrast, longitudinal data indicate that both GE (r = 0.54, p<0.001) and TIL abundance (p = 0.009) are stronger predictors for the reduction of tumor size, while low FOXP3+ was statistically significantly associated with an improved DFS (p = 0.027). In conclusion, GE analysis, TIL and FOXP3+ enumeration after short-term exposure to chemotherapy carry important predictive information in HR+/HER2- breast cancer at the neoadjuvant setting.

Abstract 1026: A multiplex IHC evaluation of multiple immune checkpoint receptors and mismatch repair proteins in colorectal carcinoma

Abstract Introduction: The recent success of checkpoint inhibitor therapies in clinical oncology practice has generated overwhelming enthusiasm for immunotherapeutics. Recent studies have suggested that patients with mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) colorectal carcinoma (CRC) may benefit from anti-PD-1/PD-L1 inhibitors. In this study, we have evaluated a large panel of immune checkpoint receptors (ICRs) on CRC by multiplex immunohistochemistry (IHC). Design: Tissue sections were initially reviewed by H&amp;E to confirm the presence of adequate pathological features including histology, grade and abundance of tumor-infiltrating lymphocytes (TILs). An MMR protein panel (MLH1, MSH2, MSH6, PMS2) was tested by IHC to determine dMMR/MSI-H status through loss of MLH1/PMS2 or MSH2/MSH6. Multiple ICRs, including CD4, CD8, CD137, CTLA-4, FOXP3, GITR, IDO1, LAG-3, PD-1, and PD-L1, were then tested by multiplex IHC on 18 CRC cases consisting of MSI-H CRCs (n=8) and microsatellite stable (MSS) CRCs (n=10) using four chromogenic end-points. Expression of ICRs in TILs was determined at four sites: tumor, invasive margin, peri-tumor, and tertiary lymphoid structures (TLS). ICR expression levels were determined by counting and averaging positive TILs in three high-power fields (400X) and categorized in the following manner: 0 (negative, no expression), 1 (weak, 1-25 cells), 2 (moderate, 26-50 cells), 3 (high, &amp;gt;50 cells). Results: Five cases of MSS (50%) and two cases of MSI-H showed 10-30% PD-L1 positive tumor cell expression. The remaining cases were negative for PD-L1. All cases of MSI-H and MSS demonstrated high expression of CD8 in tumor, invasive margin, peri-tumor and TLS. Five MSI-H cases showed moderate to high PD-1, and three MSI-H cases were weak for PD-1. All MSS cases showed weak to moderate PD-1 expression. CD4, FOXP3, CTLA-4, IDO1, LAG-3, and CD137 were weak to moderate in all MSI-H and MSS cases. Within the TLS, the predominant cellular components were CD8+, CD4+ and PD-1+ T cells in all cases. Conclusion: In the present study, a greater number of MSS CRCs expressed PD-L1 than MSI-H CRCs. PD-1 was positive in all CRC cases with variable expression between MSI-H and MSS CRCs. There appears to be no significant difference in TIL expression of additional immune checkpoint receptors tested in MSI-H colorectal carcinomas and MSS colorectal carcinomas. Multiplex technology appears to allow for superior evaluation of the synergistic relationship between immune checkpoint receptors as well as the interconnection between inhibitory barriers to CD8+ effector T cells and regulatory T cells developed by immune checkpoint receptors within each of the tumoral regions. Further study of expression patterns of immune checkpoint receptors may provide useful information for clinical management of patients with colorectal carcinoma. Citation Format: George Yang, Sara Figueroa, David Tacha, Cristin Douglas. A multiplex IHC evaluation of multiple immune checkpoint receptors and mismatch repair proteins in colorectal carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1026.

Abstract 1256: Lynch syndrome premalignancy upregulates immune checkpoints independently from neoantigen and mutational rates

Abstract Colorectal carcinomas in Lynch syndrome (LS) patients arise in a background of mismatch repair deficiency that leads to the accumulation of high numbers of mutations and neoantigens, thus causing infiltration by abundant tumor-infiltrating lymphocytes, a unique immune profile with upregulation of immune checkpoints, and response to immunotherapy. However, there is still a knowledge gap with regards to the level of immune activation and the assessment of mutation and neoantigen rates in LS premalignancy. We performed whole transcriptomic analysis using next-generation sequencing in a total of 28 colorectal polyps (26 tubular adenomas and 2 hyperplastic polyps) from 21 patients diagnosed with LS (n=11) and FAP (n=10) as comparators and a model of mismatch repair proficient colorectal premalignancy.Overall, LS polyps presented with low mutational and neoantigen rates but displayed a strinking immune activation profile characterized by CD4 T-cells, proinflammatory (TNF, IL12) and checkpoint molecules (LAG-3 and PD-L1). This immune profile was independent of mutational rate, neoantigen formation, and MMR status. In addition, we identified a small subset of LS polyps with high mutational and neoantigen rates that were secondary to accumulation of indels enriched for deregulation of DNA damage repair pathways (ATM and BRCA1 signaling). Our findings challenge the canonical model, based on the observations made in carcinomas, that emphasizes a dependency of immune activation on the acquisition of high levels of mutations and neoantigens, thus opening the door to the implementation of immune checkpoint inhibitors and vaccines for cancer prevention in Lynch syndrome. Citation Format: Kyle Chang. Lynch syndrome premalignancy upregulates immune checkpoints independently from neoantigen and mutational rates [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1256.

PD-1/PD-L1 expression in a series of intracranial germinoma and its association with Foxp3+ and CD8+ infiltrating lymphocytes.

One histopathological characteristic of intracranial germinoma is abundant tumor-infiltrating lymphocytes (TILs) showing a two-cell pattern with large undifferentiated tumor cells. The programmed cell death 1 (PD-1)/programmed cell death 1 ligand (PD-L) axis has recently been recognized as an anti-tumor immune system. To evaluate intratumor immune status in intracranial germinoma, we examined expressions of PD-1 and PD-L1 (clone 28–8) and subtypes of TILs. Expressions of PD-1 and PD-L1 were detected immunohistochemically in 25 formalin-fixed, paraffin-embedded tumor specimens from 24 patients with intracranial germinoma consisting of 22 primary and 3 recurrent tumors. To evaluate subtypes of TILs, quantification of lymphocytes with CD3, CD8, CD4, and Foxp3 was performed. Statistical analyses were performed among PD-1, PD-L1 and subtypes of TILs. In 25 tumor tissue, expressions of PD-1 in TILs and PD-L1 in tumor cells were identified in 96% (24/25) and 92% (23/25), respectively. Expression of PD-1 was associated with CD3+ TIL density. Expression of PD-1 correlated with Foxp3+ TIL density and CD8+ TIL density, but not with CD4+ TIL density. Furthermore, expression of PD-1 correlated strongly with Foxp3+/CD4+ ratio. Taken together, increase of PD-1+ expression is associated with accumulation of Foxp3+ and CD8+ TILs. These findings intimate that PD-1/PD-L1 axis might shape the immune infiltration suggesting a modulation of the immune response and subsequent tumor growth in intracranial germinoma. Anti-PD-1 and anti-PD-L1 are potential immune therapeutic strategies in intracranial germinoma.

Prognostic Significance of PD-L1+ and CD8+ Immune Cells in HPV+ Oropharyngeal Squamous Cell Carcinoma.

Human papilloma virus-positive oropharyngeal squamous cell carcinoma (HPV+ OPSCC) represents a distinct subgroup of head and neck cancers associated with clinical outcomes that are not accurately categorized by existing tumor-node-metastasis-based staging methods. Given the significant impact of immune parameters, such as tumor-infiltrating lymphocytes (TIL) in many cancers, we sought to determine if immunophenotyping tumors can improve categorization of HPV+ OPSCCs for prognostic purposes. In a cohort of 190 patients with HPV+ OPSCC, we quantified and determined the localization of CD8+ TILs, as well as PD-L1-expressing tumor cells (TC) and immune cells (IC). The prognostic significance of these parameters on overall survival (OS) was evaluated, and their contribution to existing prognostic models was determined. High CD8+ TIL abundance (≥30% on stromal or intratumoral ICs) was seen in 61.3% patients and was associated with improved OS [HR, 0.4; 95% confidence interval (CI), 0.2-0.9; P = 0.017]. Although the expression of PD-L1 on TC was not prognostic, high expression of PD-L1 on ≥5% of intratumoral ICs was found in 38.5% patients and was significantly associated with improved OS (HR, 0.37; 95% CI, 0.15-0.93; P = 0. 023). Both high intratumoral IC PD-L1 expression and abundant CD8+ TILs in HPV+ OPSCCs identify subgroups of patients with excellent outcomes and provide additional prognostic information beyond existing staging systems. Cancer Immunol Res; 6(3); 295-304. ©2018 AACR.

PD1 protein expression in tumor infiltrated lymphocytes rather than PDL1 in tumor cells predicts survival in triple-negative breast cancer

ABSTRACTTo determine PD1/PDL1 expression status in triple-negative breast cancer (TNBC) at both protein and mRNA levels, and to analyze the relationship between their expression and clinical parameters of the TNBC patients.Immunohistochemistry and RNAscope were used to semi quantitively evaluate PD1/PDL1 protein and mRNA expression in 195 TNBC cases on tissue microarrays. Tumor infiltrating lymphocyte (TILs) abundance was assessed using hematoxylin-eosin staining. Both tumor cells and TILs expressed PDL1. PDL1 protein and mRNA positivity was 6.7% and 74.4% respectively in tumor cells, and 31.3% and 50.9% respectively in TILs. PDL1 protein and mRNA expressions had no significant association with patient prognosis. PD1 protein was only detected in TILs (70.3% positivity). PD1 protein expression was significantly related to PDL1 expression, higher TIL abundance, Ki-67 index, basal-like subtypes, and distant metastasis. Furthermore, it was significantly associated with longer disease free survival (P<0.001) and overall survival (P = 0.004). There was no significant association between PD1 mRNA expression and clinicopathological characteristics. PD1/PDL1 protein and mRNA expressions were inconsistent (kappa = 0.705 and 0.061, respectively). PD1 protein expression in TILs, but not PDL1 in tumor cells, was a favorable prognostic factor in TNBC. PD1/PDL1 mRNA and protein expressions were inconsistent.

Microsatellite Instability: A Predictive Biomarker for Cancer Immunotherapy.

Immunotherapy has shown promising results in various types of cancers. Checkpoint inhibitor drugs developed for cancer immunotherapy have been approved by the US Food and Drug Administration (FDA) for patients with advanced melanoma, non-small cell lung cancer, renal cell carcinoma, bladder cancers, and refractory Hodgkin lymphoma. In the latest announcement, the FDA has granted accelerated approval to pembrolizumab for pediatric and adult patients with microsatellite instability-high (MSI-H) or mismatch repair-deficient solid tumors. This is the first time the agency has approved a cancer treatment based on a common biomarker rather than organ-based approach. MSI-H, either due to inherited germline mutations of mismatch repair genes or epigenetic inactivation of these genes, is found in a subset of colorectal and noncolorectal carcinomas. It is known that MSI-H causes a build up of somatic mutations in tumor cells and leads to a spectrum of molecular and biological changes including high tumor mutational burden, increased expression of neoantigens and abundant tumor-infiltrating lymphocytes. These changes have been linked to increased sensitivity to checkpoint inhibitor drugs. In this mini review, we provide an update on MSI-related solid tumors with special focus on the predictive role of MSI for checkpoint immunotherapy.

Analytical Validation of a Next-Generation Sequencing Assay to Monitor Immune Responses in Solid Tumors

We have developed a next-generation sequencing assay to quantify biomarkers of the host immune response in formalin-fixed, paraffin-embedded (FFPE) tumor specimens. This assay aims to provide clinicians with a comprehensive characterization of the immunologic tumor microenvironment as a guide for therapeutic decisions on patients with solid tumors. The assay relies on RNA-sequencing (seq) to semiquantitatively measure the levels of 43 transcripts related to anticancer immune responses and 11 transcripts that reflect the relative abundance of tumor-infiltrating lymphocytes, as well as on DNA-seq to estimate mutational burden. The assay has a clinically relevant 5-day turnaround time and can be conducted on as little as 2.5 ng of RNA and 1.8 ng of genomic DNA extracted from three to five standard FFPE sections. The standardized next-generation sequencing workflow produced sequencing reads adequate for clinical testing of matched RNA and DNA from several samples in a single run. Assay performance for gene-specific sensitivity, linearity, dynamic range, and detection threshold was estimated across a wide range of actual and artificial FFPE samples selected or generated to address preanalytical variability linked to specimen features (eg, tumor-infiltrating lymphocyte abundance, percentage of necrosis), and analytical variability linked to assay features (eg, batch size, run, day, operator). Analytical precision studies demonstrated that the assay is highly reproducible and accurate compared with established orthogonal approaches.

LAG-3 Protein Expression in Non–Small Cell Lung Cancer and Its Relationship with PD-1/PD-L1 and Tumor-Infiltrating Lymphocytes

IntroductionImmunotherapy targeting the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) checkpoint has shown promising efficacy in patients with NSCLC. Lymphocyte activating 3 gene (LAG-3) is another important checkpoint, and its role in NSCLC is still not clear. In this study we investigated lymphocyte activing 3 (LAG-3) protein expression; its correlation with PD-1, PD-L1, and tumor-infiltrating lymphocytes (TILs); and its association with survival in NSCLC. MethodsThe expression of LAG-3 (EPR4392 [Abcam, Cambridge, MA]) protein was assessed in 55 NSCLC cell lines by immunohistochemistry. LAG-3, PD-1 (NAT 105 [Cell Marque, Rocklin, CA]), and PD-L1 (22C3 [Dako, Carpenteria, CA]) protein expression was evaluated by immunohistochemistry, and TIL abundance was scored in 139 surgically resected specimens from patients with NSCLC. We also verified results in samples from 62 patients with untreated NSCLC and detected a correlation between LAG-3 expression and EGFR and KRAS mutation and echinoderm microtubule associated protein like 4 gene (EML4)–anaplastic lymphoma receptor tyrosine kinase gene (ALK) rearrangement. ResultsLAG-3 was not expressed on any of the 55 NSCLC cell lines. However, LAG-3 was expressed on the TILs in 36 patients with NSCLC (25.9%). Sixty patient samples (43.2%) were positive for PD-1 on the TILs, and 25 (18.0%) were positive for PD-L1 on tumor cells. Neither LAG-3 nor PD-1 was expressed on the tumor cells. LAG-3 was overexpressed on the TILs in nonadenocarcinoma compared with in adenocarcinoma (p = 0.031). LAG-3 expression on TILs was significantly correlated with that of PD-1 on TILs (p < 0.001) and PD-L1 on tumor cells (p = 0.041) but not with TIL percentage (p = 0.244). With the logistic regression model, the ORs for LAG-3 were 0.320 (95% confidence interval [CI]: 0.110–0.929) and 4.364 (95% CI: 1.898–10.031) when nonadenocarcinoma was compared with adenocarcinoma and TILs that were negative for PD-1 were compared with those positive for PD-1. Recurrence-free survival was significantly different in patients whose TILs were LAG-3–negative as opposed to LAG-3–positive (1.91 years [95% CI: 0.76–3.06] versus 0.87 years [95% CI: 0.27–1.47] [p = 0.025]). Likewise, LAG-3 status of TILs (negative versus positive) did significantly affect overall survival (OS) (3.04 years [95% CI: 2.76–3.32] versus 1.08 years [95% CI: 0.42–1.74] [p = 0.039]). Using Kaplan-Meier analysis, we found that patients with both PD-L1–negative tumor cells and LAG-3–negative TILs have longer recurrence-free survival than patients who are either PD-L1– or LAG-3–positive or both PD-L1– and LAG-3–positive (2.09 years [95% CI: 0.90–3.28] versus 1.42 years [95% CI: 0.46–2.34] versus 0.67 years [95% CI: 0.00–1.45] [p = 0.007]). In the verification stage, high expression of LAG-3 was also significantly correlated with higher expression of PD-1 on TILs (p = 0.016) and PD-L1 on tumor cells (p = 0.014). There was no correlation between LAG-3 expression and EGFR (p = 0.325) and KRAS mutation (p = 1.000) and ALK fusion (p = 0.562). ConclusionsLAG-3 is expressed on TILs in tumor tissues of some patients with NSCLC. Its expression was higher in nonadenocarcinoma and correlated with PD-1/PD-L1 expression. LAG-3 positivity or both LAG-3 and PD-L1 positivity was correlated with early postoperative recurrence. LAG-3 was related to poor prognosis.

PUB044 TIM-3 Protein Expression in Non-Small Cell Lung Cancer and Its Relationship with PD-1/PD-L1 and Tumor-Infiltrating Lymphocytes

Immunotherapy targeting the programmed death-1 (PD-1) / programmed death ligand-1 (PD-L1) checkpoint has shown promising efficacy in patients with non-small cell lung cancer (NSCLC). T-cell immunoglobulin domain and mucin domain-3 (TIM-3) is another important checkpoint, and its role in NSCLC is still not clear. In this study, we investigated TIM-3 protein expression and its correlation with PD-1, PD-L1, tumor-infiltrating lymphocytes (TILs), and association with survival in NSCLC. TIM-3 (D5D5R, Cell signaling), PD-1 (NAT 105, Cell marque) and PD-L1 (22C3, Dako) protein expression was evaluated by IHC, and TIL abundance was scored, in 132 surgically resected specimens from patients with NSCLC. TIM-3 was expressed on the TILs in 18 (13.6%) patients. 58 patient samples (43.9%) were positive for PD-1 on the TILs, and 23 (17.4%) were positive for PD-L1 on tumor cells. Neither TIM -3 nor PD-1 was expressed on the tumor cells. TIM-3 was over expressed on the TILs in adenocarcinoma compared to non-adenocarcinoma (P=0.011). TIM-3 expression on TILs was significantly correlated to that of PD-1 on TILs (P=0.011). In our study, there was no significant difference in recurrence-free survival (RFS) and overall survival (OS) between TIM-3 positive and negative. TIM-3 expresses on TILs in tumor tissues of some NSCLC patients. Its expression was higher in adenocarcinoma and was correlated with PD-1.

PD-L1 expression on immune cells, but not on tumor cells, is a favorable prognostic factor for head and neck cancer patients.

To investigate the expression of programmed death-ligand 1 (PD-L1) and immune checkpoints and their prognostic value for resected head and neck squamous cell cancer (HNSCC). PD-L1 expression on tumor cells (TC) and tumor-infiltrating immune cells (IC), abundance of tumor-infiltrating lymphocytes (TILs), and expression of the immune checkpoints were investigated in 402 HNSCC patients. PD-L1 expression on TC and IC was categorized into four groups according to the percentage of PD-L1-positive cells. PD-L1 positivity was defined as ≥5% of cells based on immunohistochemistry. High PD-L1 expression on IC, but not TC, was an independent favorable prognostic factor for RFS and OS adjusted for age, gender, smoking, stage, and HPV. High frequencies of CD3+ or CD8+ TILs, Foxp3+ Tregs, and PD-1+ TILs were strongly associated with favorable prognosis. PD-L1 was exclusively expressed on either TC or IC. Transcriptome analysis demonstrated that IC3 expressed higher levels of the effector T cell markers than TC3, suggesting that PD-L1 expression is regulated via an adaptive IFNγ-mediated mechanism. High PD-L1 expression on IC, but not TC, and high abundance of PD-1+ T cells and Foxp3+ Tregs are favorable prognostic factors for resected HNSCC. This study highlights the importance of comprehensive assessment of both TC and IC.

Abstract 4136: Properties of the immune microenvironment associated with clonal diversity in high-grade serous ovarian cancer

Abstract High-grade serous ovarian cancer (HGSC) is a challenging disease characterized by poor survival and relapse. Our group has revealed extensive clonal diversity of malignant cells in HGSC, which is thought to facilitate the emergence of resistance and recurrence in response to chemotherapy. Moreover, we have shown that the presence of tumor infiltrating lymphocytes (TILs) is associated with longer patient survival in HGSC, suggesting that the immune system can contend with the clonal diversity of tumors in some patients. We sought to determine how TIL abundance and repertoire diversity relates to the degree of tumor clone diversity in HGSC. We performed whole-genome sequencing, targeted amplicon deep sequencing, gene expression profiling, and T-cell receptor sequencing on 34 spatially separated HGSC tumor samples (8 patients) including ovarian masses and peritoneal foci. In addition, tissue sections were immunohistochemically stained for CD3, CD8, CD20, CD79a, and CD138 to detect major TIL subsets. Using PyClone, we decomposed each tumor sample into its constituent malignant clones and inferred clonal genotypes. We discovered profound intra- and inter-patient variation in the degree of tumor clone diversity from phylogenetic analysis. Widespread inter-patient variation was also observed in TIL counts and T-cell receptor repertoires. Intraepithelial CD3+ cell counts ranged from 2.2-173.2 per HPF and the number of unique T-cell receptor clonotypes varied from 422 to 3164 per sample. Remarkably, quantitative metrics of tumor clone diversity—as defined by phylogenetic divergence and entropy in the malignant composition of each tumor—was associated with the ‘proliferative’ molecular subtype and, accordingly, low TIL density. Tumor clone diversity showed no correlation with the number of unique T-cell receptor species. Moreover, preliminary analyses reveal no association between tumor clone diversity and the expression of several ligands and receptors involved in inhibitory immune signaling (CTLA-4, PD-1, PD-L1, PD-L2). Our results reveal an association between low TIL abundance and high diversity of malignant clones. This suggests that immune infiltration may inhibit tumor proliferation and clonal diversification, or vice versa. Collectively, our findings expose a relationship of the immune microenvironment with the clonal dynamics of malignant cells that could be exploited to overcome therapeutic resistance associated with clonal evolution in HGSC. Citation Format: Allen W. Zhang, Andrew McPherson, Andrew Roth, David R. Kroeger, Katy Milne, Wyeth W. Wasserman, Jessica N. McAlpine, Robert A. Holt, Brad H. Nelson, Sohrab P. Shah. Properties of the immune microenvironment associated with clonal diversity in high-grade serous ovarian cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4136.