Abstract 6513: Single cell and spatial profiling reveal molecular and immune evolution from precancers to invasive lung adenocarcinomas in genetic and carcinogen-induced mouse models

Introduction: An improved understanding of early lung carcinogenesis may facilitate development of novel diagnostic, screening, and prevention strategies to decrease lung cancer mortality. We have previously led a series of studies on the molecular and immune landscape of lung adenocarcinoma (LUAD) precursors. However, resected human specimens only provide molecular snapshots. Here, we sought to establish and characterize human-relevant murine lung precancer models to depict molecular evolution during early lung carcinogenesis and to provide novel insights for lung cancer interception.

Methods: We have established 3 genetically engineered mouse models (GEMMs) (K: KrasLSL-G12D/+, KP: KrasLSL-G12D/+/Trp53R172H/+, KL: KrasLSL-G12D/+/Lkb1fl/fl) and 2 carcinogen-induced models (CITMs) (UWT: Urethane in wild type mice, URG: Urethane in Rag2−/− mice). Lung tissues were serially collected at multiple time points after induction and subjected to whole exome sequencing (WES), single cell RNA sequencing (scRNA-seq), spatial transcriptomics (Visium), and imaging mass cytometry (IMC).

Results: Pathological review of specimens from 252 mice revealed normal lung, precancers and LUAD at different timepoints mirroring the evolution of human LUAD. Overall, the tumor burden was significantly higher in GEMMs than CITMs (p<0.05). Tumor mutation burden progressively increased with progression from precancers to LUADs across all models. scRNA-seq demonstrated a progressive decrease of CD4+ T cell, CD8+ T cell, NK cell, and B cell infiltration in all models except the B/T cell-deficient WRG model; and a progressive increase of neutrophils (in KL model) and macrophages (in K, KP, UWT and URG models) along with progression of precancers. These findings were confirmed by spatial Visium and IMC profiling. Infiltration of T cells, B cells and NK cells inside tumors was not different between GEMMs (K, KP, KL) and CITMs (UWT). However, UWT showed significantly higher density of immune cells at the peritumor regions (P<0.05). Compared to the immune-competent UWT model, the B/T-cell deficient URG model showed similar progression and tumor burden at early phases, but rapid progression and larger tumor burden in the later phases. URG had no mature B/T cells but significantly higher NK cell infiltration than UWT (p<0.05).

Conclusion: We have established 5 murine carcinogen-dependent and -independent precancer models, morphologically resembling human LUAD and its precursors. Although progressive immunosuppression along with progression of lung precancers is universal across all models, the evolution patterns and the molecular/immune features underlying immunosuppression vary in different models, particularly between CITMs and GEMMs. These models may be valuable assets for studying early lung carcinogenesis and lung cancer interception.

Citation Format: Bo Zhu, Jian-Rong Li, Hong Chen, Pingjun Chen, Junya Fujimoto, Yanhua Tian, Muhammad Aminu, Chenyang Li, Lingzhi Hong, Alexandre Reuben, Edwin Roger Parra Cuentas, Ou Shi, Monique Nilsson, Alissa Poteete, Shawna Hubert, Khaja Khan, Wei Lu, Daniel Kraushaar, Xingzhi Song, Jianhua Zhang, Don Gibbons, Luisa Solis Soto, Ignacio Wistuba, Jia Wu, John Heymach, Chao Cheng, Jianjun Zhang. Single cell and spatial profiling reveal molecular and immune evolution from precancers to invasive lung adenocarcinomas in genetic and carcinogen-induced mouse models. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6513.

Tumor Immune Microenvironment Changes by Multiplex Immunofluorescence Staining in a Pilot Study of Neoadjuvant Talazoparib for Early-Stage Breast Cancer Patients with a Hereditary BRCA Mutation

PURPOSE

The immunological profile of early-stage breast cancer treated with neoadjuvant PARP inhibitors has not been described. The aim of this study was to delineate the changes in the tumor immune microenvironment (TiME) induced by talazoparib.

PATIENTS AND METHODS

Patients with operable germline BRCA1/2 pathogenic variant (gBRCA1/2+) breast cancer were enrolled in a feasibility study of neoadjuvant talazoparib. Thirteen patients who received 8 weeks of neoadjuvant talazoparib were available for analysis, including 11 paired pre- and post-talazoparib core biopsies. Treatment-related changes in tumor-infiltrating lymphocytes were examined and immune cell phenotypes and their spatial distribution in the TiME were identified and quantified by multiplex immunofluorescence using a panel of 6 biomarkers (CD3, CD8, CD68, PD-1, PD-L1, and CK).

RESULTS

Neoadjuvant talazoparib significantly increased infiltrating intratumoral and stromal T-cell and cytotoxic T-cell density. There was no difference in PD-1 or PD-L1 immune cell phenotypes in the pre- and post-talazoparib specimens and PD-L1 expression in tumor cells was rare in this cohort. Spatial analysis demonstrated that pre-talazoparib interactions between macrophages and T cells may correlate with pathologic complete response.

CONCLUSIONS

This is the first study with phenotyping to characterize the immune response to neoadjuvant talazoparib in patients with gBRCA1/2+ breast cancer. These findings support an emerging role for PARP inhibitors in enhancing tumor immunogenicity. Further investigation of combinatorial strategies is warranted with agents that exploit the immunomodulatory effects of PARP inhibitors on the TiME.

917 Immune landscape at the invasion front of surgically resected oral squamous cell carcinomas shows significant associations with disease specific survival

Background

Oral squamous cell carcinomas (OSCC) prognosis remains poor. While AJCC TNM 8th edition has slightly improved patients‘ stratification with regard to prognostic, innovative approaches to are still needed. As in other tumor types, tumor immune microenvironment (TiME) might represent an opportunity to improve prognostic assessment.

Methods

TiME landscape of 47 HPV-negative OSCC was analyzed using multiplex immunofluorescence (mIF). Markers for tumor cells (PanCK), tumor infiltrating lymphocytes (CD3, CD8), macrophages (CD68), inhibitory (PD-1, PD-L1, TIM3, LAG3, VISTA) or stimulatory (OX40, ICOS) immune checkpoints (ICP) were studied. Regions of interest (ROI), 5 in the tumor core and 5 at the invasion front, were subjected to cell markers identification and quantification (scoring) as well as tissue compartmentalization to divide them in tumor-epithelial and tumor-stroma compartments, respectively. A total of 20 cell phenotypes were defined based on previous work (CK+, CK+PD-L1+, CD3+, CD3+CD8+, CD3+PD-1+, CD3+CD8+PD-1+, CD3+PD-L1+, CD3+CD8+PD-L1+, CD3+PD-L1+PD-1+, CD3+CD8+PD-L1+PD-1+, CD68+, CD68+PD-L1+, CK+OX40+, CD3+VISTA+, CD3+ICOS+, CD3+LAG3+, CD3+OX-40+, CD3+TIM3+). Results were correlated with clinical features including disease-specific survival (DSS) using the Kaplan-Meier method and a multivariate Cox model. A multivariate general linear model (GLM) was built to test the specific association of each variable with a given cell density by correcting the possible confusion due to other variables.

Results

Immune cells densities were significantly higher overall in the stroma. The intra-tumor stroma showed a significant enrichment of in CD3+PD-1+ T cells compared to peri-tumor stroma. None of the clinical or pathological (resection margin, tumor stage, lymph node invasion, perineural invasion) was significantly associated with DSS. In contrast, the following cell phenotypes in the tumor invasion front were strongly associated with a poor DSS, including CD3+PD-L1+ (P-value= 0.004), CD3+PD1+PD-L1+ (P-value= 0.02) and CD3+OX40+ (P-value= 0.02) T cells as well as CD3+CD8+PD-1+ (P-value= 0.048), CD3+CD8+PD-L1+ (P-value= 0.008) and CD3+CD8+PD1+PD-L1+ (P-value= 0.01) cytotoxic T cells. In the tumor core, CD68+PD-L1- macrophages (P-value= 0.06) were marginally associated with better DSS. Using a GLM, we found that tumor from smoker-drinker patients and/or with pN+, were significantly more infiltrated by PD-1- and/or PD-L1-positive immune cells. On the other hand, floor of mouth and gingiva-mandibular OSCC were significantly less infiltrated than others.

Conclusions

The prognostic value of PD-1+ and/or PD-L1+ cells in the invasion front of resected OSCC was remarkable, underlying the importance of this area when studying the TiME. Incorporating TiME analysis in the invasion front may improve prognostic evaluation of patients treated for OSCC, especially in the context of immunotherapy.

Acknowledgements

This study was supported by a strategic alliance between the Translational Molecular Pathology-Immunoprofiling las (TMP-IL) at the Department Translational Molecular Pathology, the University of Texas MD Anderson Cancer Center and the Université Claude Bernard Lyon, Centre de Recherche en Cancérologie de Lyon and the Department of Translational Medicine, Centre Léon Bérard, Lyon, France. The authors would acknowledge ITMO Cancer 2020, ”Formation à la Recherche Fondamentale et Translationnelle en Cancérologie” (JB); CLARA 2020 ”Soutien à la mobilité des jeunes chercheurs en oncologie, N° CVPPRCAN000198” (JB); Fondation de France 2020 ”Aide à la mobilité international de médecins et pharmaciens, N° 00112162” (JB); Ligue contre le cancer 2021, comité de Saône-et-Loire (PS); 2017-INCa-DGOS-Inserm_12563: INCa SIRIC-LYriCAN INCa-DGOS-Inserm_12563 (PS)

Ethics Approval

The study was conducted in accordance with all applicable laws, rules, and requests of French and European government authorities. Written informed consent was obtained from all patients and the study was approved by the Centre Leon Bérard institutional review board (Lyon, France). Samples were obtained from the CRB Centre Léon Bérard (n°BB-0033-00050) which is quality certified according NFS96-900 French standard and ISO 9001 for clinical trials.

Consent

Written informed consent was obtained from all patients and the study was approved by the Centre Leon Bérard institutional review board (Lyon, France)

Immune Phenotype and Response to Neoadjuvant Therapy in Triple-Negative Breast Cancer

PURPOSE

Increasing tumor-infiltrating lymphocytes (TIL) is associated with higher rates of pathologic complete response (pCR) to neoadjuvant therapy (NAT) in patients with triple-negative breast cancer (TNBC). However, the presence of TILs does not consistently predict pCR, therefore, the current study was undertaken to more fully characterize the immune cell response and its association with pCR.

EXPERIMENTAL DESIGN

We obtained pretreatment core-needle biopsies from 105 patients with stage I-III TNBC enrolled in ARTEMIS (NCT02276443) who received NAT from Oct 22, 2015 through July 24, 2018. The tumor-immune microenvironment was comprehensively profiled by performing T-cell receptor (TCR) sequencing, programmed death-ligand 1 (PD-L1) IHC, multiplex immunofluorescence, and RNA sequencing on pretreatment tumor samples. The primary endpoint was pathologic response to NAT.

RESULTS

The pCR rate was 40% (42/105). Higher TCR clonality (median = 0.2 vs. 0.1, P = 0.03), PD-L1 positivity (OR: 2.91, P = 0.020), higher CD3⁺:CD68⁺ ratio (median = 14.70 vs. 8.20, P = 0.0128), and closer spatial proximity of T cells to tumor cells (median = 19.26 vs. 21.94 μm, P = 0.0169) were associated with pCR. In a multivariable model, closer spatial proximity of T cells to tumor cells and PD-L1 expression enhanced prediction of pCR when considered in conjunction with clinical stage.

CONCLUSIONS

In patients receiving NAT for TNBC, deep immune profiling through detailed phenotypic characterization and spatial analysis can improve prediction of pCR in patients receiving NAT for TNBC when considered with traditional clinical parameters.

Relevance of PD-L1 Non-Coding Polymorphisms on the Prognosis of a Genetically Admixed NSCLC Cohort

Purpose

Although non-small cell lung cancer (NSCLC) remains a deadly disease, new predictive biomarkers have emerged to assist in managing the disease, of which one of the most promising is the programmed death‐ligand 1 (PD-L1). Each, PD-L1 variant seem to modulate the function of immune checkpoints differently and affect response to adjuvant treatment and outcome in NSCLC patients. We thus investigated the influence of these PD-L1 genetic variations in genetically admixed NSCLC tissue samples, and correlated these values with clinicopathological characteristics, including prognosis.

Materials and Methods

We evaluated PD-L1 non-coding genetic variants and protein expression in lung adenocarcinomas (ADC), squamous cell carcinomas (SqCC), and large cell carcinomas (LCC) in silico. Microarray paraffin blocks from 70 samples of ADC (N=33), SqCC (N=24), and LCC (N=13) were used to create PD-L1 multiplex immunofluorescence assays with a Cell Signaling E1L3N clone. Fifteen polymorphisms of the PD-L1 gene were investigated by targeted sequencing and evaluated in silico using dedicated tools.

Results

Although PD-L1 polymorphisms seemed not to interfere with protein expression, PD-L1 expression varied among different histological subtypes, as did clinical outcomes, with the rs4742098A>G, rs4143815G>C, and rs7041009G>A variants being associated with relapse (P=0.01; P=0.05; P=0.02, respectively). The rs7041009 GG genotype showed a significant correlation with younger and alive patients compared to carriers of the A allele (P=0.02 and P<0.01, respectively). The Cox regression model showed that the rs7041009 GG genotype may influence OS (P<0.01) as a co-dependent factor associated with radiotherapy and recurrence in NSCLC patients. Furthermore, the Kaplan–Meier survival curves showed that rs7041009 and rs4742098 might impact PPS in relapsed patients. In silico approaches identified the variants as benign.

Conclusion

PD-L1 non-coding variants play an important role in modulating immune checkpoint function and may be explored as immunotherapy biomarkers. We highlight the rs7041009 variant, which impacts OS and PPS in NSCLC patients.

Consensus molecular subtype (CMS) as a novel integral biomarker in colorectal cancer: A phase II trial of bintrafusp alfa in CMS4 metastatic CRC

4084

Background: Consensus Molecular Subtype 4 (CMS4) colorectal cancer (CRC) features increased TGFβ signaling, which may account for de novo resistance to immunotherapy for patients (pts) with microsatellite stable mCRC. To date, no prior trial has incorporated CMS status as an integral biomarker. Bintrafusp alfa (M7824) is a dual PD-L1 antibody/TGFβ trap with acceptable safety. Methods: Primary tumors from pts with metastatic CRC underwent CMS testing in a CLIA setting. In this Simon two-stage phase II trial (Ho: p < .05; Ha: p≥.25) for CMS4 mCRC, pts received bintrafusp alfa 1200mg IV every 14 days. RT (8Gy/day x 3 days) to a single metastatic lesion with abscopal intent was administered between doses 2 and 3. The primary objective was to estimate response rate (RR) per iRECIST. Correlative studies including RNA sequencing were performed on pre- and on-treatment biopsies. Results: 53 of 137 tested pts (39%) between June 2018-December 2019 had CMS4 mCRC. 13 of 15 treated pts received the agent with RT. All pts were evaluable for toxicity, and 13 for response. Median number of doses was 3 (IQR, 2-4). There was one grade 3 immune-related adverse event (colitis) requiring study discontinuation. There were 2 pts with stable disease and 11 with progressive disease as best response (RR 0%, 95% CI 0-22%). Enrollment was stopped after first stage for futility. Median PFS and OS were 1.6 months and 5.0 months, respectively. In paired samples, treatment with bintrafusp alfa resulted in an increase in the expression of IFNγ signature in nonirradiated metastatic lesions ( p< .001, q< .001). Updated results will be presented. Conclusions: This is the first reported clinical trial to utilize CMS status as an integral biomarker for pts with metastatic CRC and capitalizes on treating CRC subpopulations with targeted agents based upon validated RNA-based signatures. Although the efficacy for bintrafusp alfa and RT is low, changes in IFNγ signature provides a potential signal for refining therapeutic strategies based upon TGFβ enrichment in pts with mCRC. Clinical trial information: NCT03436563 .

Immune phenotype and response to neoadjuvant systemic therapy (NAST) in triple negative breast cancer (TNBC)

509

Background: In TNBC patients (pts) receiving NAST, increasing tumor infiltrating lymphocytes (TILs) is associated with higher pathologic complete response (pCR) rates. However, since the presence of TIL do not consistently predict pCR, the current study was undertaken to more fully characterize the immune cell response and its association with pCR. Methods: T cell receptor (TCR) sequencing, PD-L1 immunohistochemistry and multiplex immunofluorescence were performed on prospectively collected pre-NAST tumor samples from 98 pts with stage I-III TNBC enrolled in ARTEMIS (NCT: 02276443). TCR clonality was calculated using Shannon’s entropy. PD-L1+ was defined as ≥1% immune cell staining. Response to NAST was defined using the residual cancer burden (RCB) index. Associations between TCR clonality, immune phenotype, and response were examined with the Wilcoxon rank sum test, Spearman’s rank correlation and multivariable logistic regression using stepwise elimination (threshold p > 0.2), as appropriate. Results: The pCR rate was 39% (38/98). pCR was associated with higher TCR clonality (median = 0.2 [in pts with pCR] vs 0.1 [in pts with residual disease], p = 0.05). Notably, the association between pCR and higher TCR clonality was observed in pts with ≥5% TIL (n = 61; p = 0.05) but not in pts with < 5% TIL (n = 37; p = 0.87). Among pts with ≥5% TIL, TCR clonality emerged as the only independent predictor of response in a multivariable model of tumor immune characteristics (odds ratio/0.1 increase in TCR clonality: 3.0, p = 0.021). PD-L1+ status was associated with higher TCR clonality (median = 0.2 [in PD-L1+] vs 0.1 [in PD-L1-], p = 0.004). Higher TCR clonality was associated with higher CD3+ (rho = 0.32, p = 0.0018) and CD3+CD8+ (rho = 0.33, p = 0.0013) infiltration but lower expression of PD-1 on CD3+ (rho = -0.24, p = 0.021) and CD3+CD8+ cells (rho = -0.21, p = 0.037). Conclusions: In TNBC, a more clonal T cell population is associated with an immunologically active microenvironment (higher CD3+ and CD3/8+ T cell; lower PD-1+CD3+ and PD-1+CD3/8+ T cell; PD-L1+) and favorable response to NAST, especially in pts with ≥5% TIL, suggesting a role for deep immune phenotyping in further refining the predictive value of TILs.

CIMAC-CIDC tissue imaging harmonization

3125

Background: The Cancer Immune Monitoring and Analysis Centers Cancer Immunology Data Commons (CIMAC-CIDC) network is a NCI Cancer Moonshots initiative to provide state-of-the-art technology and expertise for immunotherapy clinical trials. Multiplex tissue immunostaining is an integral assay provided that examines density and spatial distribution of immune cells and markers in tissues, for their prognostic or predictive value. Two approaches were evaluated for sensitivity, specificity, and reproducibility and subsequently harmonized: chromogenic-based Multiplex Immunohistochemical Consecutive Staining on Single Slide (MICSSS) and Multiplex Immunofluorescence (mIF) based tyramide signal amplification system. Methods: Harmonization was performed across CIMACs (Mount Sinai, Dana Farber Cancer Institute, MD Anderson Cancer Center) in multiple steps to prove that comparable data can be generated independent of site and platform. Goals: 1) harmonize image analysis platforms alone using tissues pre-stained with single chromogenic IHC for CD3 (membrane), Ki67 (nuclear), and CD68 (cytoplasmic), 2) compare image acquisition platforms, 3) streamline Antibody (Ab) clones and assess PD-L1 detection in relation to CLIA- assays, 4) harmonize staining protocols, image acquisition, and analysis platforms on 2 test head and neck tumor samples using MICSSS and mIF, 5) validate harmonization results with a tissue microarray on 27 tissues representing multiple tumors. For last steps, each CIMAC used their platforms for PD-L1, PD-1, CD3, CD8, and pan-cytokeratin (PanCK) staining on one of three consecutive slides from serial sections and compared densities of each marker. Results: Variables as PD-1 Ab clone, positive control reference tissues, sigma value for nuclear segmentation, and use of machine-learning based cell classifier were found to be key to produce accurate, reliable, comparable data. After visual quality control assessment and comparisons of each Region Of Interest (ROI), an overall inter-site Spearman correlation coefficient of ≥0.85 was achieved per marker within each tissue and across tissue types (expect pan-Cytokeratin, ≥0.7), with average coefficient of variation ≤0.1. Conclusions: These results show for the first time that two platforms can deliver harmonized data, despite differences in protocols, platforms, reagents, and analysis tools. Data resulting from retrospective and prospective CIMAC-CIDC analyses may be used with confidence for statistical associations with clinical parameters and outcome.

Tumor immune microenvironment alterations in penile squamous cell carcinoma using multiplex immunofluorescence and image analysis approaches

4

Background: Penile Squamous Cell Carcinoma (PSCC) is a rare but often fatal disease. In this study, we characterize the poorly understood immune microenvironment using multiplex immunofluorescence (mIF) and image analysis approaches in 54 patients with PSCC. Methods: Representative blocks of 54 PSCC patients were stained for six immune markers: CD3, CD8, CD68, PD-1, PD-L1, Pancytokeratin and DAPI. Two experienced pathologists using an image analysis system (InForm 2.2.4) divided them into the tumor and stroma compartment and assessed the different densities of cell phenotypes using R studio with results expressed as cells/mm2. The statistical correlations were performed using Fisher’s exact test, Pearson and Log-rank test for Kaplan Meyer plots. Results: 54 patients with confirmed diagnosis of PSCC had a median age of 62 (IQR 50-70). All samples were from the primary penile tumor with the majority of cases being HPV(–) (62%). We observed significantly higher stromal cytotoxic T cells in HPV(+) cases compared to HPV(–) ( P=0.04). Using the mean macrophage count as cutoff for positivity, high densities of total tumor macrophages CD68+ were associated with significantly improved estimated median cancer specific survival (CSS) (NA, P=0.04), median overall survival (OS) (68mos vs NA P=0.02) and lower risk of regional recurrence ( P=0.04). On the other hand, the high densities of stromal cytotoxic T cells antigen-experienced (CD3+CD8+PD-1+), was associated with significantly worse median OS (27 vs 102mos P=0.05) and median disease free survival (DFS) (18.2mos vs NA P= 0.07). Also, high densities of stromal T cells antigen-experienced (CD3+PDL-1+), were associated with significantly better CSS (NA, P=0.06) and better median OS (142.1 vs 68.8mos P=0.14). Conclusions: Using novel multiplex image analysis to assess the immune microenvironment in primary PSCC, we showed that high macrophage levels were associated with lower risk of recurrence and improved survival outcomes. Moreover, a low level of exhausted stromal cytotoxic PD-1+ T cells was associated with improved PSCC survival. Further characterization of T cell subsets in relation to tumor HPV status is ongoing.

Association of relative neutrophilia with a distinct immunoinhibitory milieu in non-small cell lung cancer

e14047

Background: Elevated neutrophil-to-lymphocyte ratio (NLR) has been associated with poor prognosis in non-small cell lung cancer (NSCLC); the biological underpinnings of this observation have not been fully elucidated. We examined the relationships between peripheral neutrophil counts (PMN), NLR, circulating cytokines and angiogenic factors (CAF), and tumor microenvironment (TME) features in NSCLC. Methods: 150 patients with resectable NSCLC were enrolled in an immunoprofiling project. A panel of 43 CAFs was used to analyze preoperative plasma samples. Chemotherapy-naïve patients with CAF and a complete blood count ≤30 days preoperatively were included (n = 66; Table). For a subset, transcriptional signatures (MCP-counter, n = 50) and flow cytometry (n = 19) were used to identify TME phenotypes. Results: Increased PMNs were associated with increased pro-inflammatory CAF such as IL-1b (r = 0.392) and IL-6 (r = 0.339), as well as Th17/Tc17 associated CAF IL-17A (r = 0.320) and TNF-a (r = 0.368). Elevated NLR was inversely correlated with the lymphocyte activation marker soluble CD27 (r = -0.320, p = 0.009). This negative association was mirrored in the TME, as tumor neutrophil signatures were inversely correlated with a local IFN-g gene signature (r = -0.626, p < 0.001). Interestingly, a Th17/Tc17 peripheral signature (elevated IL-17A) was associated with an enrichment of CD8+TIM3+ cells (r = 0.623, p = 0.042) in the tumor. While this requires confirmation in a larger cohort, this correlation provides a potential rationale for targeting TIM3 in this population. Upon analysis of clinical characteristics, peripheral PMNs and NLR were higher among patients with squamous histology (PMN p = 0.009; NLR p = 0.034) and positively correlated with tumor size (PMN r = 0.344, p = 0.004; NLR r = 0.363, p = 0.003). Conclusions: A relative neutrophilia in NSCLC patients is associated with an inflammatory milieu suggestive of a Th17/Tc17 presence and decreased lymphocyte activation that is reflected within the TME. Further investigation is needed to define the role of NLR as a predictive biomarker and to identify whether neutrophils or Th17/Tc17 T cells could serve as a therapeutic target to improve immunotherapy response in NSCLC.[Table: see text]

Neoadjuvant nivolumab (N) or nivolumab plus ipilimumab (NI) for resectable non-small cell lung cancer (NSCLC): Clinical and correlative results from the NEOSTAR study

8504

Background: Neoadjuvant immune checkpoint inhibitors (ICIs) induce major pathologic response (MPR) rates of 20 to 45% in resected NSCLCs. We report the results of NEOSTAR - a phase 2 trial of neoadjuvant N or NI for NSCLCs. Methods: Pts with stage I-IIIA (single N2) resectable NSCLC (AJCC 7th), PS 0-1, were randomized to N (3 mg/kg IV, D1, 15, 29) or N plus I (1 mg/kg IV, D1) followed by surgery (n = 44). Primary endpoint: MPR (≤10% viable tumor), hypothesized to be higher than MPR to induction chemotherapy historical controls. Tumor immune infiltrates and pre- & post-ICI tumor PD-L1 % were assessed by flow cytometry & IHC. Wilcoxon ranked sum test & Fisher’s exact test were used for comparisons. Results: 44 pts were randomized, 23 N, 21 NI: mean age 66, 64% males, 18% never smokers, 59% adenocarcinomas, stages: IA 8 (18%), IB 15 (34%), IIA 7 (16%) IIB 5 (11%); IIIA 9 (20%). Only 3 pts received < 3 doses due to TRAEs (7%). 34 pts had surgery post ICIs (7 not resected [7/41], 17%, [2 N, 5 NI], 3 pending). There were 10 MPRs in 41 pts overall (24%, 4 N, 6 NI), of which 6 were path CRs (15%, 2 N [9%], 4 NI [21%]). Among 34 resected pts, MPR rate was 29% (N 20%, NI 43%). Median % of viable tumor was lower post NI vs N (20% vs 65%, p = .097). ORR (RECIST v1.1) was 22% (8 PRs [5 N, 3 NI], 1 CR [NI]); 15% of pts had PD (3 N, 3 NI). The proportion of CR+PR in MPR+ was higher than in MPR- (6 [60%] vs 2 [7%], p < .001). Surgical complications included 2 bronchopleural fistulas (BPFs) in N & 8 air leaks (5 N, 3 NI). G3-G5 TRAEs included a death due to BPF post steroid-treated pneumonitis (G5, N); G3 pneumonia, hypoxia, hypermagnesemia (1 each, all N), G3 diarrhea (1 NI). CD3+ & CD103+ tissue resident memory CD8+ TILs were higher in NI- vs N-treated tumors (CD3+ 81.2% vs 54.4%, p = .028; CD8+ 56.2% vs 38.3%, p = .069). Median pre-treatment tumor PD-L1 was higher in responders (MPR+, CR+PR) vs non-responders (80% vs 1%, p = .024), and the % of viable tumor was lower in tumors with PD-L1 > 1% vs PD-L1 ≤1% (median 20% vs 80%, p = .046). Conclusions: Overall a 24% MPR rate to neoadjuvant ICIs was observed. NI induced a higher % of non-viable tumor and of tissue resident memory TILs vs N. Antitumor activity was associated with higher pre-treatment PD-L1 levels. Clinical trial information: NCT03158129.

Tumor immune microenvironment (TiME) changes by multiplex IF staining in a pilot study of neoadjuvant talazoparib for early-stage breast cancer patients with a BRCA mutation

585

Background: We previously reported a median tumor volume loss of 88% (range 30-98%) in 13 patients with early stage BRCA1/2 mutant breast cancer treated on a neoadjuvant trial of the PARP inhibitor talazoparib. The effects of PARP inhibition on immune aspects of the TiME in early-stage breast cancer has not been well described. The goal of this study was to evaluate the TiME in pre and post-treatment core biopsies from enrolled patients. Methods: Eleven paired core biopsies were available for examination. Tumor infiltrating lymphocytes (TILs) were quantified by H&E stained slides by a central pathologist. Specimens were assessed by multiplex immunofluorescence (mIF) using a panel of 6 biomarkers (PD-1, PD-L1, CD3, CD8, CD68 and CK) with the Opal 7-color Kit in LEICA BOND auto stainer, Vectra automated quantitative pathology imaging system and inForm software (PerkinElmer). Results: In the analyzed core biopsies, there was an increase in TILs evaluated by H&E in post-treatment compared to baseline (mean 36 vs 11%). By mIF there was an increase in CD3+ T cell and CD3+CD8+ cytotoxic T cell density in post-treatment samples compared to baseline, summarized in table. PD-L1 expression in tumor cells was rare in the cohort. There was no difference in CD3+PD-1+ or CD3+CD8+ PD-1+ lymphocytes in pre and post-treatment specimens. There was also no differences in macrophages (CD68+). Evaluation of immune phenotype and imaging response will be presented in the final analysis. Conclusions: This is the first study phenotyping the immune response to neoadjuvant talazoparib in BRCA-mutant breast cancer patients. In this small cohort, intratumoral and stromal CD3+ T cells and CD3+CD8+ cytotoxic T cells increased after two months of talazoparib. Clinical trial information: NCT02282345. [Table: see text]

Development and Validation of a Predictive Radiomics Model for Clinical Outcomes in Stage I Non-small Cell Lung Cancer

PURPOSE

To develop and validate a radiomics signature that can predict the clinical outcomes for patients with stage I non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

We retrospectively analyzed contrast-enhanced computed tomography images of patients from a training cohort (n = 147) treated with surgery and an independent validation cohort (n = 295) treated with stereotactic ablative radiation therapy. Twelve radiomics features with established strategies for filtering and preprocessing were extracted. The random survival forests (RSF) method was used to build models from subsets of the 12 candidate features based on their survival relevance and generate a mortality risk index for each observation in the training set. An optimal model was selected, and its ability to predict clinical outcomes was evaluated in the validation set using predicted mortality risk indexes.

RESULTS

The optimal RSF model, consisting of 2 predictive features, kurtosis and the gray level co-occurrence matrix feature homogeneity2, allowed for significant risk stratification (log-rank P < .0001) and remained an independent predictor of overall survival after adjusting for age, tumor volume and histologic type, and Karnofsky performance status (hazard ratio [HR] 1.27; P < 2e-16) in the training set. The resultant mortality risk indexes were significantly associated with overall survival in the validation set (log-rank P = .0173; HR 1.02, P = .0438). They were also significant for distant metastasis (log-rank P < .05; HR 1.04, P = .0407) and were borderline significant for regional recurrence on univariate analysis (log-rank P < .05; HR 1.04, P = .0617).

CONCLUSIONS

Our radiomics model accurately predicted several clinical outcomes and allowed pretreatment risk stratification in stage I NSCLC, allowing the choice of treatment to be tailored to each patient's individual risk profile.

Immune profiling of oral pre-malignant lesions (OPLs): An Erlotinib Prevention of Oral Cancer (EPOC) study biobank analysis

1545

Background: We previously demonstrated that high-risk loss of heterozygosity (LOH) profiles (i.e., 3p14/9p21 LOH) and EGFR gene copy number gain (CNG) in OPLs were associated with inferior oral cancer-free survival (OCFS) in patients enrolled in the randomized EPOC trial. Herein, we performed comprehensive immune profiling of OPLs and correlated the findings with molecular features and outcomes, using the prospectively collected and clinically annotated EPOC biobank. Methods: We evaluated OPL specimens by multiplex immunofluorescence using the Opal 7-color fIHC Kit and the Vectra multispectral microscope / inForm Cell Analysis software. Markers included AE1/AE3 pancytokeratins, PD-L1 (clone E1L3N), CD3, CD8, and CD68. Wilcoxon rank-sum and Fisher’s exact tests were used to assess the associations between binary markers and continuous and categorical variables, respectively. Cox model was used to investigate associations of markers with OCFS. Results: The cohort included 188 OPL patients with hyperkeratosis/hyperplasia (18%), mild/moderate (44%), or severe dysplasia (5%); 65% had high-risk LOH profiles. The 5-year OCFS was 72.3% (median follow-up of 50 months). PD-L1 expression in > 1% of epithelial cells occurred in 28% of OPLs. Intraepithelial CD3+, CD3+/CD8+, CD68+, and CD68+/PD-L1+ cells were detected in 100%, 88%, 88%, and 54% of the samples, respectively. OPLs with high-risk LOH profiles had increased epithelial PD-L1 expression (P = 0.007), intraepithelial CD68+/PD-L1+ cells (P = 0.002), and a trend towards more CD3+/CD8+ cells in the stroma (P = 0.06) but not in the epithelium (P = 0.97), compared with low-risk LOH OPLs. Increased epithelial PD-L1 expression was associated with inferior OCFS on univariate (P = 0.023), and multivariate analysis including LOH status and EGFR CNG as co-variates (P = 0.018). Conclusions: High-risk OPLs defined by LOH profiles had increased PD-L1 expression in epithelial cells and intraepithelial macrophages, as well as stromal CD3+/CD8+ immune infiltration. Higher PD-L1 expression was associated with increased oral cancer risk. The findings may support evaluation of (PD-1-targeted) immunoprevention strategies in high-risk OPLs.

Epithelial-Mesenchymal Transition Is Associated with a Distinct Tumor Microenvironment Including Elevation of Inflammatory Signals and Multiple Immune Checkpoints in Lung Adenocarcinoma

PURPOSE

Promising results in the treatment of non-small cell lung cancer (NSCLC) have been seen with agents targeting immune checkpoints, such as programmed cell death 1 (PD-1) or programmed death ligand-1 (PD-L1). However, only a select group of patients respond to these interventions. The identification of biomarkers that predict clinical benefit to immune checkpoint blockade is critical to successful clinical translation of these agents.

METHODS

We conducted an integrated analysis of three independent large datasets, including The Cancer Genome Atlas of lung adenocarcinoma and two datasets from MD Anderson Cancer Center (Houston, TX), Profiling of Resistance Patterns and Oncogenic Signaling Pathways in Evaluation of Cancers of the Thorax (named PROSPECT) and Biomarker-Integrated Approaches of Targeted Therapy for Lung Cancer Elimination (named BATTLE-1). Comprehensive analysis of mRNA gene expression, reverse-phase protein array, IHC, and correlation with clinical data were performed.

RESULTS

Epithelial-mesenchymal transition (EMT) is highly associated with an inflammatory tumor microenvironment in lung adenocarcinoma, independent of tumor mutational burden. We found immune activation coexistent with elevation of multiple targetable immune checkpoint molecules, including PD-L1, PD-L2, PD-1, TIM-3, B7-H3, BTLA, and CTLA-4, along with increases in tumor infiltration by CD4(+)Foxp3(+) regulatory T cells in lung adenocarcinomas that displayed an EMT phenotype. Furthermore, we identify B7-H3 as a prognostic marker for NSCLC.

CONCLUSIONS

The strong association between EMT status and an inflammatory tumor microenvironment with elevation of multiple targetable immune checkpoint molecules warrants further investigation of using EMT as a predictive biomarker for immune checkpoint blockade agents and other immunotherapies in NSCLC and possibly a broad range of other cancers. Clin Cancer Res; 22(14); 3630-42. ©2016 AACRSee related commentary by Datar and Schalper, p. 3422.

Cancer-Associated Fibroblasts Induce a Collagen Cross-link Switch in Tumor Stroma

Intratumoral collagen cross-links heighten stromal stiffness and stimulate tumor cell invasion, but it is unclear how collagen cross-linking is regulated in epithelial tumors. To address this question, we used Kras(LA1) mice, which develop lung adenocarcinomas from somatic activation of a Kras(G12D) allele. The lung tumors in Kras(LA1) mice were highly fibrotic and contained cancer-associated fibroblasts (CAF) that produced collagen and generated stiffness in collagen gels. In xenograft tumors generated by injection of wild-type mice with lung adenocarcinoma cells alone or in combination with CAFs, the total concentration of collagen cross-links was the same in tumors generated with or without CAFs, but coinjected tumors had higher hydroxylysine aldehyde-derived collagen cross-links (HLCC) and lower lysine-aldehyde-derived collagen cross-links (LCCs). Therefore, we postulated that an LCC-to-HLCC switch induced by CAFs promotes the migratory and invasive properties of lung adenocarcinoma cells. To test this hypothesis, we created coculture models in which CAFs are positioned interstitially or peripherally in tumor cell aggregates, mimicking distinct spatial orientations of CAFs in human lung cancer. In both contexts, CAFs enhanced the invasive properties of tumor cells in three-dimensional (3D) collagen gels. Tumor cell aggregates that attached to CAF networks on a Matrigel surface dissociated and migrated on the networks. Lysyl hydroxylase 2 (PLOD2/LH2), which drives HLCC formation, was expressed in CAFs, and LH2 depletion abrogated the ability of CAFs to promote tumor cell invasion and migration.

IMPLICATIONS

CAFs induce a collagen cross-link switch in tumor stroma to influence the invasive properties of tumor cells.