Uncovering immune checkpoint heterogeneity in oral squamous cell carcinoma using single cell RNA-sequencing data highlights three subgroups of patients with distinct immune phenotypes.

OBJECTIVES: In head and neck squamous cell carcinoma (HNSCC), PD-1/PD-L1 inhibitors remain inefficient in most patients, which points to the need for better characterization of immune checkpoint (ICP) molecule expression. MATERIAL AND METHODS: We evaluated the expression of 22 ICP ligands (ICPL) in 2,176 malignant cells from 10 patients in a public single-cell RNA-sequencing dataset and in two cohorts of HNSCC patients for which gene expression data are available. RESULTS: Based on ICPL expression, malignant cells formed three distinct clusters characterized either by a strong expression of ICPL together with an immune phenotype linked to IFN-γ response (cluster 1) or by a weak ICPL expression and little response to IFN-γ (clusters 2 and 3). Malignant cells from cluster 3 showed a high PD-L1 expression associated with NRF2 signature. The relevance of 3 groups of patients, i.e "high ICPL/high IFN-γ", "low ICPL/low IFN-γ" or "low ICPL/low IFN-γ/high PD-L1" was confirmed in a cohort of 259 OSCC whole tumor samples from TCGA and in the CLB-IHN cohort including patients treated with PD1/PD-L1 inhibitors. The heterogeneous expression of ICPL among patients' malignant cells was associated with immunologically distinct microenvironments, evaluated with the "hot/cold" and the Tumor microenvironment (TME) classification. Finally, the "low ICPL/low IFN-γ/high PD-L1" group 3 displayed a poor prognosis in the TCGA cohort. CONCLUSION: Hence, the global picture of ICPL gene expression in malignant cells from HNSCC patients may contribute to the broader issue of improving immunotherapy strategies though a better stratification of patients and the design of new treatment combinations.

Datasets for gene expression profiles of head and neck squamous cell carcinoma and lung cancer treated or not by PD1/PD-L1 inhibitors.

Identification of tumors harboring an overall active immune phenotype may help for selecting patients with advanced head and neck squamous cell carcinomas (HNSCC) and non-small cell lung cancer (NSCLC) who may benefit from immunotherapies. In this context, we generated targeted gene expression profiles in three and two independent cohorts of patients with HNSCC or NSCLC respectively, treated or not by PD-1/PD-L1 inhibitors. Notably, we generated two datasets including 102 and 82 patients with HNSCC or NSCLC treated with PD-1/PD-L1 inhibitors. Clinical information, including detailed survival raw data, is available for each patient, allowing to test association between gene expression data and patient survival (overall and progression-free survival). Moreover, we also generated gene expression datasets of 27 paired HNSCC samples from diagnostic biopsies and versus surgically resected specimens as well as 33 paired HNSCC samples at initial diagnosis (untreated) and at recurrence. Those datasets may allow to test the stability of a given biomarker across paired samples.

Immunologically active phenotype by gene expression profiling is associated with clinical benefit from PD-1/PD-L1 inhibitors in real-world head and neck and lung cancer patients.

INTRODUCTION: Identification of tumours harbouring an overall active immune phenotype may help for selecting patients with advanced head and neck squamous cell carcinomas (HNSCC) and non-small cell lung cancer (NSCLC) who may benefit from immunotherapies. Our objective was to develop a reliable and stable scoring system to identify those immunologically active tumours. METHODS: Using gene expression profiles of 421 HNSCC, we developed a score to identify immunologically active tumours. Validation of the 'HOT' score was done in 40 HNSCC and 992 NSCLC. Stability of the 'HOT' score was tested in paired HNSCC samples from diagnostic biopsies versus surgically resected specimens, untreated versus recurrent samples, and pre-versus post-cetuximab samples in a total of 76 patients. The association between the 'HOT' score with overall survival (OS) and progression-free survival (PFS) was tested in 184 patients with HNSCC or NSCLC treated with PD-1/PD-L1 inhibitors. RESULTS: A 27-gene expression based 'HOT' score was correlated with: (i) PD-L1 and IDO1 expression, (ii) TCD8 infiltrate and (iii) activation of the IFN-γ pathway. The HOT score concordance when comparing diagnostic biopsies and surgically resected specimens was higher than in untreated samples versus recurrent or pre-versus post-cetuximab samples. In 102 and 82 patients with HNSCC or NSCLC treated with PD-1/PD-L1 inhibitors, the HOT score was associated with an improved OS and PFS in multivariate analysis. CONCLUSION: The 'HOT' score is a simple and robust approach to identify real-world patients with HNSCC and NSCLC immunologically active tumours who may benefit from PD-1/PD-L1 inhibitors.

Teaching how to break bad news in Oncology: In-class vs. virtual peer role-plays.

BACKGROUND: We report two different peer role-play training courses for breaking bad news (BBN) in Oncology, the classic "in-class" model and the "virtual" peer role-play (VPRP) model developed during the SARS-CoV-2 pandemic. METHODS: Each session included 20-25 4th year medical students supervised by two practitioners experienced in oncology. After an ice breaking activity to exchange with students on means to promote hope to patients when BBN, peer role-plays started. Pre-and post-session questionnaires were submitted to evaluate students' satisfaction, attitudes, and perceptions. Pre-and post-session knowledge test were realized. Each student has participated to only one peer-role play either "in-class" (2018) or VPRP (2020). RESULTS: In 2018, a total of 222 students received the "in-class" training. In 2020, a total 431 students received the VPRP training. For almost all students it was the first peer role-play training session. Before training, reported level of confidence in BBN was low. After training, students of the VPRP group were highly satisfied regarding quality (realism, organization). Students also reported great interest and perceived benefits. Students who underwent "in-class" training course showed a significantly higher improvement (+1.9 points) of their knowledge scores compared to those who underwent the VPRP training course (+0.7 points) (P-value=2e-16). CONCLUSION: The two methods seem beneficial to improve knowledge skills in BBN although "in-class" training class seem to be more efficient. To our knowledge, this is the first comparison between virtual and in-class peer-role play training for BBN in oncology.

Epithelial-to-mesenchymal transition promotes immune escape by inducing CD70 in non-small cell lung cancer.

INTRODUCTION: Epithelial-to-mesenchymal transition (EMT) is associated with tumor aggressiveness, drug resistance, and poor survival in non-small cell lung cancer (NSCLC) and other cancers. The identification of immune-checkpoint ligands (ICPLs) associated with NSCLCs that display a mesenchymal phenotype (mNSCLC) could help to define subgroups of patients who may benefit from treatment strategies using immunotherapy. METHODS: We evaluated ICPL expression in silico in 130 NSCLC cell lines. In vitro, CRISPR/Cas9-mediated knockdown and lentiviral expression were used to assess the impact of ZEB1 expression on CD70. Gene expression profiles of lung cancer samples from the TCGA (n = 1018) and a dataset from MD Anderson Cancer Center (n = 275) were analyzed. Independent validation was performed by immunohistochemistry and targeted-RNA sequencing in 154 NSCLC whole sections, including a large cohort of pulmonary sarcomatoid carcinomas (SC, n = 55). RESULTS: We uncover that the expression of CD70, a regulatory ligand from the tumor necrosis factor ligand family, is enriched in mNSCLC in vitro models. Mechanistically, the EMT-inducer ZEB1 impacted CD70 expression and fostered increased activity of the CD70 promoter. CD70 overexpression was also evidenced in mNSCLC patient tumor samples and was particularly enriched in SC, a lung cancer subtype associated with poor prognosis. In these tumors, CD70 expression was associated with decreased CD3+ and CD8+ T-cell infiltration and increased T-cell exhaustion markers. CONCLUSION: Our results provide evidence on the pivotal roles of CD70 and ZEB1 in immune escape in mNSCLC, suggesting that EMT might promote cancer progression and metastasis by not only increasing cancer cell plasticity but also reprogramming the immune response in the local tumor microenvironment.

PD-1 Blockade in Solid Tumors with Defects in Polymerase Epsilon.

Missense mutations in the polymerase epsilon (POLE) gene have been reported to generate proofreading defects resulting in an ultramutated genome and to sensitize tumors to checkpoint blockade immunotherapy. However, many POLE-mutated tumors do not respond to such treatment. To better understand the link between POLE mutation variants and response to immunotherapy, we prospectively assessed the efficacy of nivolumab in a multicenter clinical trial in patients bearing advanced mismatch repair-proficient POLE-mutated solid tumors. We found that only tumors harboring selective POLE pathogenic mutations in the DNA binding or catalytic site of the exonuclease domain presented high mutational burden with a specific single-base substitution signature, high T-cell infiltrates, and a high response rate to anti-PD-1 monotherapy. This study illustrates how specific DNA repair defects sensitize to immunotherapy. POLE proofreading deficiency represents a novel agnostic biomarker for response to PD-1 checkpoint blockade therapy. SIGNIFICANCE: POLE proofreading deficiency leads to high tumor mutational burden with high tumor-infiltrating lymphocytes and predicts anti-PD-1 efficacy in mismatch repair-proficient tumors. Conversely, tumors harboring POLE mutations not affecting proofreading derived no benefit from PD-1 blockade. POLE proofreading deficiency is a new tissue-agnostic biomarker for cancer immunotherapy. This article is highlighted in the In This Issue feature, p. 1397.

MEK1/2 inhibition transiently alters the tumor immune microenvironment to enhance immunotherapy efficacy against head and neck cancer.

BACKGROUND: Although the mitogen-activated protein kinases (MAPK) pathway is hyperactive in head and neck cancer (HNC), inhibition of MEK1/2 in HNC patients has not shown clinically meaningful activity. Therefore, we aimed to characterize the effect of MEK1/2 inhibition on the tumor microenvironment (TME) of MAPK-driven HNC, elucidate tumor-host interaction mechanisms facilitating immune escape on treatment, and apply rationale-based therapy combination immunotherapy and MEK1/2 inhibitor to induce tumor clearance. METHODS: Mouse syngeneic tumors and xenografts experiments were used to analyze tumor growth in vivo. Single-cell cytometry by time of flight, flow cytometry, and tissue stainings were used to profile the TME in response to trametinib (MEK1/2 inhibitor). Co-culture of myeloid-derived suppressor cells (MDSC) with CD8+ T cells was used to measure immune suppression. Overexpression of colony-stimulating factor-1 (CSF-1) in tumor cells was used to show the effect of tumor-derived CSF-1 on sensitivity to trametinib and anti-programmed death- 1 (αPD-1) in mice. In HNC patients, the ratio between CSF-1 and CD8A was measured to test the association with clinical benefit to αPD-1 and αPD-L1 treatment. RESULTS: Using preclinical HNC models, we demonstrated that treatment with trametinib delays HNC initiation and progression by reducing tumor cell proliferation and enhancing the antitumor immunity of CD8+ T cells. Activation of CD8+ T cells by supplementation with αPD-1 antibody eliminated tumors and induced an immune memory in the cured mice. Mechanistically, an early response to trametinib treatment sensitized tumors to αPD-1-supplementation by attenuating the expression of tumor-derived CSF-1, which reduced the abundance of two CSF-1R+CD11c+ MDSC populations in the TME. In contrast, prolonged treatment with trametinib abolished the antitumor activity of αPD-1, because tumor cells undergoing the epithelial to mesenchymal transition in response to trametinib restored CSF-1 expression and recreated an immune-suppressive TME. CONCLUSION: Our findings provide the rationale for testing the trametinib/αPD-1 combination in HNC and highlight the importance of sensitizing tumors to αPD-1 by using MEK1/2 to interfere with the tumor-host interaction. Moreover, we describe the concept that treatment of cancer with a targeted therapy transiently induces an immune-active microenvironment, and supplementation of immunotherapy during this time further activates the antitumor machinery to cause tumor elimination.

Early changes in the immune microenvironment of oral potentially malignant disorders reveal an unexpected association of M2 macrophages with oral cancer free survival.

Understanding the dynamics of the immune microenvironment is critical to the development of immuno-based strategies for the prevention of oral potentially malignant disorders transformation to oral squamous cell carcinoma (OSCC). We used laser capture microdissection and RNA-sequencing to profile the expression of 13 matched pairs of epithelial versus stromal compartments from normal mucosa, hyperplasia, dysplasia, and invasive tumors in the 4-nitroquinolein (4-NQO) murine model of oral carcinogenesis. Genes differentially expressed at each step of transformation were defined. Immune cell deconvolution and enrichment scores of various biological processes including immune-related ones were computed. Immunohistochemistry was also performed to characterize the immune infiltrates by T-cells (T-cells CD3+, helper CD4+, cytotoxic CD8+, regulatory FoxP3+), B-cells (B220+), and macrophages (M1 iNOS+, M2 CD163+) at each histological step. Enrichment of three independent M2 macrophages signatures were computed in 86 oral leukoplakia with available clinical outcome. Most gene expression changes were observed in the stromal compartment and related to immune biological processes. Immune cell deconvolution identified infiltration by the macrophage population as the most important quantitatively especially at the stage of dysplasia. In 86 patients with oral leukoplakia, three M2 macrophages signatures were independently associated with improved oral cancer-free survival. This study provides a better understanding of the dynamics of the immune microenvironment during oral carcinogenesis and highlights an unexpected association of M2 macrophages gene expression signatures with oral cancer free survival in patients with oral leukoplakia.

Longitudinal assessment of PD-L1 expression and gene expression profiles in patients with head and neck cancer reveals temporal heterogeneity.

BACKGROUND: Programmed death-ligand 1 (PD-L1) is the most validated predictive biomarker used for the treatment of head and neck squamous cell carcinoma (HNSCC) with immune checkpoint inhibitors (ICI). Several gene expression-based signatures surrogate of the activation of IFN-gamma pathway and of the presence of tertiary lymphoid structures (TLS) have also been proposed as potential biomarkers. While they may have a potential therapeutic implication, the longitudinal changes of either PD-L1 or gene expression profiles between the initial and recurrent HNSCC lesions is unknown. METHODS: PD-L1 immunohistochemistry (IHC) and targeted RNA-sequencing of 2,549 transcripts were analyzed on paired specimens from the initial diagnosis and recurrent HNSCC. PD-L1 status was defined using the combined positive score (CPS). PD-L1 mRNA levels were compared with protein expression levels by IHC. Enrichment scores of surrogate signatures for TLS and IFN-gamma (IFN-γ) pathway activation were computed using the single sample gene set enrichment analysis (ssGSEA). RESULTS: PD-L1 status was 64% (21/33) concordant between the initial and recurrent lesions using a CPS 1 threshold and 67% (22/33) concordant using a CPS 20 threshold. CPS score was associated with PD-L1 gene expression levels. There was a 43% (15/35) and 66% (23/35) concordance for the IFN-γ and TLS signature scores, respectively. CONCLUSION: Our study reveals temporal heterogeneity of PD-L1 status and TLS/IFN-γ gene expression surrogates in HNSCC that need to be considered when interpreting biomarker studies.

Evidence for a cluster of rare birth defects in the Ain department (France).

BACKGROUND: REMERA (REgistre des Malformations En Rhône-Alpes) is a registry of congenital malformations that covers 58,000 births annually in Central-East France. In 2010, the registry raised an alarm to the health authorities (Santé publique France, SpF) about three cases of a unilateral isolated transverse upper limb reduction defect (UITULRD) in a small subarea; the general prevalence of this defect is one case in 10,000 births. In the following years, more infants were born with the same malformation in the same territory of the Ain department. Public health authorities, supported by an expert committee, rejected the existence of a cluster, but we aim here at providing evidence for this cluster. METHODS: Geocoded data for all UITULRD cases (ICD-10 codes Q71.2 and Q71.3) were extracted from the REMERA database. We conducted a Kulldorff cluster analysis of these data, using the spatial SaTScanTM algorithm. RESULTS: The analysis found a cluster of eight cases of UITULRD among the 8,204 births occurring between 2009 and 2014 within a circle of 16.24 km radius centered on a village of the Ain department, whereas 0.82 cases were expected under a uniform probability of such a birth throughout the registry territory. This represents an almost 10fold excess over the expected number of cases (p = .0057). CONCLUSIONS: The arguments used to deny the cluster are disputed and we present the evidence supporting its reality. The controversy that has followed the alarm has compromised the search for the cause(s) of this excess of rare malformations.

Assisted Reproductive Technologies and imprinting disorders: Results of a study from a French congenital malformations registry.

INTRODUCTION: Assisted Reproductive Technologies (ART) is increasingly used to help infertile couples to have children around the world. A number of studies have been published reporting an increased risk of major malformations in children born following ART, especially an increased incidence of epigenetic diseases (ED). This study aimed to assess the incidence of epigenetic diseases with affected imprinting genes in infants or children from pregnancies obtained through IVF/ICSI compared to infants or children from pregnancies obtained spontaneously. PATIENT DATA: This is a monocentric retrospective epidemiological study based on data from a French congenital malformations registry called REMERA (Registre des Malformations en Rhône-Alpes) which exhaustively monitors all pregnancies in Rhone-Alpes region, whatever their nature of onset (spontaneous pregnancies or pregnancies from ART). This registry collects all malformations, except minor malformations (EUROCAT), and all polymalformative syndromes concerning all fetuses and children born alive or not, from 20 weeks of pregnancy (or 22 weeks of amenorrhea) and all medical termination of pregnancy whatever the term. Inclusion criteria are all diagnoses of epigenetic diseases (ED) related to parental imprinting recorded in the period January 2006 to December 2015. METHODS: For each year, the total number of births (including stillbirths) was collected from the annual activity reports of the registry. The exhaustive number of cases of epigenetic diseases was known in the registry. Were collected the number of births resulting from ART pregnancies in the study population. This incidence of ED was compared between births from spontaneous pregnancies and those obtained through ART (IVF/ICSI) with a generalized linear model (GLM: binomial regression). RESULTS: In total, 46 cases of epigenetic diseases were analyzed on the REMERA registry files from 2006 to 2015. 4 cases from the 46 analyzed cases were from pregnancies induced by ART. ART was a risk factor for epigenetic disease (OR = 2.9 [1.06-8.22] (p = .039)). In ART-pregnancies there were 2 diagnoses: Beckwith-Wiedemann syndrome (BWS) (3 cases out of 4) and Silver-Russell syndrome (SRS) (1 out of 4). DISCUSSION: Infants and children obtained through IVF/ICSI appear to be related to a higher risk of epigenetic diseases compared to naturally conceived children. The perspectives of this study are to raise awareness about the creation of registries of congenital malformations and genetic and epigenetic syndromes with systematic and strict reports of all the cases on all the French territory and thus to widen this study with a bigger cohort.

Placental Pathology in Beckwith-Wiedemann Syndrome According to Genotype/Epigenotype Subgroups.

OBJECTIVES: To evaluate the frequency of placental pathological lesions in Beckwith-Wiedemann syndrome (BWS), an overgrowth disorder that exhibits etiologic molecular heterogeneity and variable phenotypic expression. MATERIALS AND METHODS: The study included 60 BWS patients with a proven molecular diagnosis and a placental pathological examination. Placentomegaly, placental mesenchymal dysplasia (PMD), chorangioma/chorangiomatosis, and extravillous trophoblastic (EVT) cytomegaly were evaluated and their frequencies in the different molecular subgroups were compared. Immunohistochemistry and fluorescent in situ hybridization (FISH) were performed on EVT cytomegaly. RESULTS: Placentomegaly was found in 70.9% of cases, PMD in 21.7%, chorangioma/chorangiomatosis in 23.3%, and EVT cytomegaly in 21.7%; there was no significant intergroup difference. EVT cytomegaly showed loss of p57 expression, increased Ki67 proliferating index, and polyploidy on FISH analysis. CONCLUSIONS: There was no genotype/epigenotype-phenotype correlation concerning placental lesions in BWS. Diffuse EVT cytomegaly with polyploidy may represent a placental finding suggestive of BWS.