Pembrolizumab plus concurrent chemoradiotherapy versus placebo plus concurrent chemoradiotherapy in patients with locally advanced squamous cell carcinoma of the head and neck (KEYNOTE-412): a randomised, double-blind, phase 3 trial

BACKGROUND

Despite multimodal therapy, 5-year overall survival for locally advanced head and neck squamous cell carcinoma (HNSCC) is about 50%. We assessed the addition of pembrolizumab to concurrent chemoradiotherapy for locally advanced HNSCC.

METHODS

In the randomised, double-blind, phase 3 KEYNOTE-412 trial, participants with newly diagnosed, high-risk, unresected locally advanced HNSCC from 130 medical centres globally were randomly assigned (1:1) to pembrolizumab (200 mg) plus chemoradiotherapy or placebo plus chemoradiotherapy. Randomisation was done using an interactive response technology system and was stratified by investigator's choice of radiotherapy regimen, tumour site and p16 status, and disease stage, with participants randomly assigned in blocks of four per stratum. Participants, investigators, and sponsor personnel were masked to treatment assignments. Local pharmacists were aware of assignments to support treatment preparation. Pembrolizumab and placebo were administered intravenously once every 3 weeks for up to 17 doses (one before chemoradiotherapy, two during chemoradiotherapy, 14 as maintenance therapy). Chemoradiotherapy included cisplatin (100 mg/m2) administered intravenously once every 3 weeks for two or three doses and accelerated or standard fractionation radiotherapy (70 Gy delivered in 35 fractions). The primary endpoint was event-free survival analysed in all randomly assigned participants. Safety was analysed in all participants who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03040999, and is active but not recruiting.

FINDINGS

Between April 19, 2017, and May 2, 2019, 804 participants were randomly assigned to the pembrolizumab group (n=402) or the placebo group (n=402). 660 (82%) of 804 participants were male, 144 (18%) were female, and 622 (77%) were White. Median study follow-up was 47·7 months (IQR 42·1-52·3). Median event-free survival was not reached (95% CI 44·7 months-not reached) in the pembrolizumab group and 46·6 months (27·5-not reached) in the placebo group (hazard ratio 0·83 [95% CI 0·68-1·03]; log-rank p=0·043 [significance threshold, p≤0·024]). 367 (92%) of 398 participants treated in the pembrolizumab group and 352 (88%) of 398 participants treated in the placebo group had grade 3 or worse adverse events. The most common grade 3 or worse adverse events were decreased neutrophil count (108 [27%] of 398 participants in the pembrolizumab group vs 100 [25%] of 398 participants in the placebo group), stomatitis (80 [20%] vs 69 [17%]), anaemia (80 [20%] vs 61 [15%]), dysphagia (76 [19%] vs 62 [16%]), and decreased lymphocyte count (76 [19%] vs 81 [20%]). Serious adverse events occurred in 245 (62%) participants in the pembrolizumab group versus 197 (49%) participants in the placebo group, most commonly pneumonia (43 [11%] vs 25 [6%]), acute kidney injury (33 [8%] vs 30 [8%]), and febrile neutropenia (24 [6%] vs seven [2%]). Treatment-related adverse events led to death in four (1%) participants in the pembrolizumab group (one participant each from aspiration pneumonia, end-stage renal disease, pneumonia, and sclerosing cholangitis) and six (2%) participants in the placebo group (three participants from pharyngeal haemorrhage and one participant each from mouth haemorrhage, post-procedural haemorrhage, and sepsis).

INTERPRETATION

Pembrolizumab plus chemoradiotherapy did not significantly improve event-free survival compared with chemoradiotherapy alone in a molecularly unselected, locally advanced HNSCC population. No new safety signals were seen. Locally advanced HNSCC remains a challenging disease that requires better treatment approaches.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.

Machine Learning-assisted immunophenotyping of peripheral blood identifies innate immune cells as best predictor of response to induction chemo-immunotherapy in head and neck squamous cell carcinoma - knowledge obtained from the CheckRad-CD8 trial

PURPOSE

Individual prediction of treatment response is crucial for personalized treatment in multimodal approaches against head-and-neck squamous cell carcinoma (HNSCC). So far, no reliable predictive parameters for treatment schemes containing immunotherapy have been identified. This study aims to predict treatment response to induction chemo-immunotherapy based on the peripheral blood immune status in patients with locally advanced HNSCC.

METHODS

The peripheral blood immune phenotype was assessed in whole blood samples in patients treated in the phase II CheckRad-CD8 trial as part of the pre-planned translational research program. Blood samples were analyzed by multicolor flow cytometry before (T1) and after (T2) induction chemo-immunotherapy with cisplatin/docetaxel/durvalumab/tremelimumab. Machine Learning techniques were used to predict pathological complete response (pCR) after induction therapy.

RESULTS

The tested classifier methods (LDA, SVM, LR, RF, DT, and XGBoost) allowed a distinct prediction of pCR. Highest accuracy was achieved with a low number of features represented as principal components. Immune parameters obtained from the absolute difference (lT2-T1l) allowed the best prediction of pCR. In general, less than 30 parameters and at most 10 principal components were needed for highly accurate predictions. Across several datasets, cells of the innate immune system such as polymorphonuclear cells, monocytes, and plasmacytoid dendritic cells are most prominent.

CONCLUSIONS

Our analyses imply that alterations of the innate immune cell distribution in the peripheral blood following induction chemo-immuno-therapy is highly predictive for pCR in HNSCC.

INHBA is Enriched in HPV-negative Oropharyngeal Squamous Cell Carcinoma and Promotes Cancer Progression

Patients with oropharyngeal squamous cell carcinoma (OPSCC) caused by human papilloma virus (HPV) exhibit a better prognosis than those with HPV-negative OPSCC. This study investigated the distinct molecular pathways that delineate HPV-negative from HPV-positive OPSCC to identify biologically relevant therapeutic targets. Bulk mRNA from 23 HPV-negative and 39 HPV-positive OPSCC tumors (n = 62) was sequenced to uncover the transcriptomic profiles. Differential expression followed by gene set enrichment analysis was performed to outline the top enriched biological process in the HPV-negative compared with HPV-positive entity. INHBA, the highest overexpressed gene in the HPV-negative tumor, was knocked down. Functional assays (migration, proliferation, cell death, stemness) were conducted to confirm the target's oncogenic role. Correlation analyses to reveal its impact on the tumor microenvironment were performed. We revealed that epithelial-to-mesenchymal transition (EMT) is the most enriched process in HPV-negative compared with HPV-positive OPSCC, with INHBA (inhibin beta A subunit) being the top upregulated gene. INHBA knockdown downregulated the expression of EMT transcription factors and attenuated migration, proliferation, stemness, and cell death resistance of OPSCC cells. We uncovered that INHBA associates with a pro-tumor microenvironment by negatively correlating with antitumor CD8+ T and B cells while positively correlating with pro-tumor M1 macrophages. We identified three miRNAs that are putatively involved in repressing INHBA expression. Our results indicate that the upregulation of INHBA is tumor-promoting. We propose INHBA as an attractive therapeutic target for the treatment of INHBA-enriched tumors in patients with HPV-negative OPSCC to ameliorate prognosis.

SIGNIFICANCE

Patients with HPV-negative OPSCC have a poorer prognosis due to distinct molecular pathways. This study reveals significant transcriptomic differences between HPV-negative and HPV-positive OPSCC, identifying INHBA as a key upregulated gene in HPV-negative OPSCC's oncogenic pathways. INHBA is crucial in promoting EMT, cell proliferation, and an immunosuppressive tumor environment, suggesting its potential as a therapeutic target for HPV-negative OPSCC.

Tumor-Infiltrating CD103+ Tissue-Resident Memory T Cells and CD103-CD8+ T Cells in HNSCC Are Linked to Outcome in Primary but not Metastatic Disease

PURPOSE

High numbers of tumor-infiltrating lymphocytes (TIL) are linked to better survival in patients with cancer. Tissue-resident memory T cells (TRM; CD8+CD103+) are recognized as a key player of anticancer immune response. To assess TRM cells in primary, metastatic, and recurrent head and neck squamous cell carcinoma (HNSCC), we developed a tissue microarray (TMA) and used multiplex IHC (MxIHC).

EXPERIMENTAL DESIGN

Samples from primary tumors of 379 HNSCC cases treated at Southampton Hospitals between 2000 and 2016 were collected and analyzed. Of these, 105 cases had lymph node metastases and 82 recurrences. A TMA was generated with triplicate cores for each sample. MxIHC with a stain-and-strip approach was performed using CD8, CD103, and TIM3. Scanned slides were analyzed (digital image analysis) and quality checked (QC).

RESULTS

After QC, 194 primary tumors, 76 lymph node metastases, and 65 recurrences were evaluable. Alcohol consumption was statistically significantly correlated with a reduction of TRM cells in primary tumors (nondrinker vs. heavy drinker: P = 0.0036). The known survival benefit of TRM cell infiltration in primary tumors was not found for lymph node metastasis. In recurrences, a high TRM cell number led to a favorable outcome after 12 months. The checkpoint molecule TIM3, was expressed significantly higher on TRM and non-TRM cells in the lymph node compared with primary tumors (P < 0.0001), which was also seen in recurrences (P = 0.0134 and P = 0.0007, respectively).

CONCLUSIONS

We confirm the prognostic impact of TIL in primary tumors and in recurrences. TRM cell density in lymph node metastases was not linked to outcome. The role of TIM3, as a therapeutic target remains to be defined.

Regional outcome disparities in German head and neck cancer patients: Shorter survival in Eastern Germany

INTRODUCTION

Demographics are important prognostic factors in malignant diseases. A nationwide analysis concerning the prognostic impact of demographics in head and neck cancer (HNC) patients (HNCP) has not been performed previously.

METHODS

A retrospective analysis of data from the Center for Cancer Registry Data (ZfKD) and the Federal Statistical Office (Destatis) between 2002 and 2017 was performed. A total of 212'920 HNCP were included. Incidence, tumor stage, age development, sex distribution, age-, residence-, and diagnosis-time-specific survival were examined.

RESULTS

Mean age of HNCP increased more rapidly than in the general population (slope coefficient: 0.29 vs. 0.20; p < 0.0001). Higher age and male sex were associated with a worse prognosis. Whereas overall survival (OS) increased from the early to the later observation period for HNCP <70 years, no OS improvement for HNCP >70 years was found. Furthermore, an OS disadvantage was observed for East Germany compared to West Germany (median 47 vs. 60 months; p < 0.0001). This disparity was associated with a disproportionately high ratio of men in East Germany (men/women: 4.4 vs. 3.1; p < 0.0001) and a lower mean age (61 vs. 63 years; p < 0.0001). In addition to stage, age and sex, residence in East Germany were confirmed as an independent factor for OS in a multivariate analysis.

CONCLUSION

Finally, three decades after the German reunion, a survival disadvantage for patients in East Germany still exists. This discrepancy may be a result of socioeconomic disparities.

Demographics and access to head and neck cancer care in rural areas compared to urban areas in Germany

BACKGROUND

Demographic development in rural and urban areas differs substantially. Demographics and access to specialized head and neck cancer centers may affect head and neck cancer patients' (HNCP) outcomes. Here, we compare epidemiological indicators and outcomes of HNCP in rural and urban Germany.

PATIENTS AND METHODS

In a retrospective analysis of data from the Center for Cancer Registry Data (ZfKD) between 2002 and 2017, 212,920 HNCP were included. Incidence, demographics, travel distance to specialized centers, and ground values were compared between rural and urban areas with a focus on their association with patient outcomes.

RESULTS

The mean age of HNCP was significantly higher in urban areas (mean difference = 1.4 years; p < 0.0001), but increased at a comparable rate (p = 0.26) in rural and urban areas during the observation period. Gender imbalance was higher in rural areas (mean ratio of men/women: 4.1 vs. 3.1; p < 0.0001), but showed a comparable trend toward equilibration in both, rural and urban districts (p = 0.46). The portion of HNCP of the entire HNCP population living in urban areas increased from 55.9% in the year 2002 to 76.4% in the year 2017. There was no significant difference or change in the ratio of advanced to low UICC stage during the observation period (p = 0.26). However, travel distances to medical centers were higher in rural areas, especially (p < 0.0001) in East Germany. Median survival of HNCP in rural areas was significantly lower than in urban areas (42 months [SEM = 0.7; CI: 40.5-43.5] vs. 54 months [SEM = 1.2; CI: 51.7-56.3]; p < 0.0001) in East Germany, whereas in West Germany no significant difference was observed (59 months [SEM = 0.8; CI: 57.4-60.6] vs. 60 months [SEM = 0.5; CI: 59.0-61.0]; p = 0.15).

CONCLUSIONS

Place of residence contributes to survival outcome of HNCP. Access to specialized care and socioeconomic factors could be improved in East Germany.

[Patient-reported outcomes in head and neck cancer treatment: relevance, challenges, and benefit]

Next to overall survival, quality of life is becoming more and more pivotal for cancer patients. The various domains of quality of life are complex and have different value to each patient. However, not only patients but also health care professionals, the pharmaceutical industry, and regulatory bodies ask: How can quality of life be reliably ascertained in clinical trials? For this purpose, carefully developed and validated specific questionnaires are needed: the patient-reported outcome measures (PROMs). A key challenge is to define how results based on PROMs can be used for shared decision-making. Next to clinical factors such as health and nutritional status, quality of life acts as a prognostic factor for overall survival in cancer. Thus, it is crucial to take quality of life into account in daily clinical practice.

Influence of Bruton's Tyrosine Kinase (BTK) on Epithelial-Mesenchymal Transition (EMT) Processes and Cancer Stem Cell (CSC) Enrichment in Head and Neck Squamous Cell Carcinoma (HNSCC)

Constitutively active kinases play a crucial role in carcinogenesis, and their inhibition is a common target for molecular tumor therapy. We recently discovered the expression of two oncogenic isoforms of Bruton's Tyrosine Kinase (BTK) in head and neck squamous cell carcinoma (HNSCC), Btk-p80 and BTK-p65. However, the precise role of BTK in HNSCC remains unclear. Analyses of a tissue microarray containing benign and malignant as well as inflammatory tissue samples of the head and neck region revealed the preferential expression of BTK-p80 in malignant tissue, whereas BTK-p65 expression was confirmed in over 80% of analyzed metastatic head and neck tumor cases. Therefore, processes associated with metastasis, like cancer stem cell (CSC) enrichment and the epithelial-mesenchymal transition (EMT), which in turn depend on an appropriate cytokine milieu, were analyzed. Treatment of HNSCC-derived cell lines cultured under 3D conditions with the BTK inhibitor AVL-292 caused reduced sphere formation, which was accompanied by reduced numbers of ALDH1A1+ CSCs as well as biological changes associated with the EMT. Moreover, we observed reduced NF-κB expression as well as altered NF-κB dependent pro-tumorigenic and EMT-associated cytokine release of IL-6, IFNγ, and TNFα when BTK activity was dampened. Therefore, an autocrine regulation of the oncogenic BTK-dependent process in HNSCC can be suggested, with BTK inhibition expected to be an effective treatment option for HNSCC.

Liquid biopsy: an examination of platelet RNA obtained from head and neck squamous cell carcinoma patients for predictive molecular tumor markers

Aim

Recently, a tumor cell-platelet interaction was identified in different tumor entities, resulting in a transfer of tumor-derived RNA into platelets, named further "tumor-educated platelets (TEP)". The present pilot study aims to investigate whether such a tumor-platelet transfer of RNA occurs also in patients suffering from head and neck squamous cell carcinoma (HNSCC).

Methods

Sequencing analysis of RNA derived from platelets of tumor patients (TPs) and healthy donors (HDs) were performed. Subsequently, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used for verification of differentially expressed genes in platelets from TPs and HDs in a second cohort of patients and HDs. Data were analyzed by applying bioinformatic tools.

Results

Sequencing of RNA derived from the tumor as well as from platelets of TPs and HDs revealed 426 significantly differentially existing RNA, at which 406 RNA were more and 20 RNA less abundant in platelets from TPs in comparison to that of HDs. In TPs' platelets, abundantly existing RNA coding for 49 genes were detected, characteristically expressed in epithelial cells and RNA, the products of which are involved in tumor progression. Applying bioinformatic tools and verification on a second TP/HD cohort, collagen type I alpha 1 chain (COL1A1) and zinc finger protein 750 (ZNF750) were identified as the strongest potentially platelet-RNA-sequencing (RNA-seq)-based biomarkers for HNSCC.

Conclusions

These results indicate a transfer of tumor-derived messenger RNA (mRNA) into platelets of HNSCC patients. Therefore, analyses of a patient's platelet RNA could be an efficient option for liquid biopsy in order to diagnose HNSCC or to monitor tumorigenesis as well as therapeutic responses at any time and in real time.

[Immunotherapy in the context of other head and neck cancer treatment modalities-highlights of the ASCO and ESMO annual meeting 2022]

Immunotherapeutic agents are nowadays established for treatment of a wide variety of tumor entities, including squamous cell carcinoma of the head and neck region. Originally used in the palliative setting, these are increasingly administered with curative intent, e.g., as neoadjuvant treatment. Current research addresses the questions of which patients benefit from the treatment and which combination therapies are successful. The present article summarizes relevant findings of the two international cancer congresses in 2022.

The HLA ligandome of oropharyngeal squamous cell carcinomas reveals shared tumour-exclusive peptides for semi-personalised vaccination

BACKGROUND

The immune peptidome of OPSCC has not previously been studied. Cancer-antigen specific vaccination may improve clinical outcome and efficacy of immune checkpoint inhibitors such as PD1/PD-L1 antibodies.

METHODS

Mapping of the OPSCC HLA ligandome was performed by mass spectrometry (MS) based analysis of naturally presented HLA ligands isolated from tumour tissue samples (n = 40) using immunoaffinity purification. The cohort included 22 HPV-positive (primarily HPV-16) and 18 HPV-negative samples. A benign reference dataset comprised of the HLA ligandomes of benign haematological and tissue datasets was used to identify tumour-associated antigens.

RESULTS

MS analysis led to the identification of naturally HLA-presented peptides in OPSCC tumour tissue. In total, 22,769 peptides from 9485 source proteins were detected on HLA class I. For HLA class II, 15,203 peptides from 4634 source proteins were discovered. By comparative profiling against the benign HLA ligandomic datasets, 29 OPSCC-associated HLA class I ligands covering 11 different HLA allotypes and nine HLA class II ligands were selected to create a peptide warehouse.

CONCLUSION

Tumour-associated peptides are HLA-presented on the cell surfaces of OPSCCs. The established warehouse of OPSCC-associated peptides can be used for downstream immunogenicity testing and peptide-based immunotherapy in (semi)personalised strategies.

Treatment dependent impact of plasma-derived exosomes from head and neck cancer patients on the epithelial-to-mesenchymal transition

Background

Epithelial to mesenchymal transition (EMT) is a key process in carcinogenesis of head and neck squamous cell carcinoma (HNSCC), contributing to tumor invasiveness, distant metastasis, and recurrence. Exosomes are known mediators and regulators of EMT. Here, we analyze the impact of exosomes that were primed by conventional therapy on EMT modulation.

Methods

Plasmas of n = 22 HNSCC patients were collected before and after standard of care surgery and adjuvant or primary (chemo)radiotherapy. Exosomes were isolated by size exclusion chromatography. Upon co-incubation of exosomes with HNSCC cells, the cellular EMT profile was analyzed by flow cytometry and RT-qPCR. Wound healing assays were performed to evaluate migratory potential of exosome-treated cells.

Results

Reduction of total exosome protein after therapy and in vitro exosome induced EMT profiles were dependent on the type of treatment. Exosomal TFG-β and miRNA cargo were partly responsible for observed exosome induced EMT changes. Exosomes from recurrent patients induced higher tumor cell migration after therapy than exosomes from disease-free patients.

Conclusions

HNSCC patients' exosomes from timepoints before and after therapy were able to confer therapy induced EMT modulation in vitro and have the potential to monitor the EMT process. Exosome induced changes in migratory potential emerged as discriminants of therapy outcome.

BTK Isoforms p80 and p65 Are Expressed in Head and Neck Squamous Cell Carcinoma (HNSCC) and Involved in Tumor Progression

Here, we describe the expression of Bruton's Tyrosine Kinase (BTK) in head and neck squamous cell carcinoma (HNSCC) cell lines as well as in primary HNSCC samples. BTK is a kinase initially thought to be expressed exclusively in cells of hematopoietic origin. Apart from the 77 kDa BTK isoform expressed in immune cells, particularly in B cells, we identified the 80 kDa and 65 kDa BTK isoforms in HNSCC, recently described as oncogenic. Importantly, we revealed that both isoforms are products of the same mRNA. By investigating the mechanism regulating oncogenic BTK-p80/p65 expression in HNSSC versus healthy or benign tissues, our data suggests that the epigenetic process of methylation might be responsible for the initiation of BTK-p80/p65 expression in HNSCC. Our findings demonstrate that chemical or genetic abrogation of BTK activity leads to inhibition of tumor progression in terms of proliferation and vascularization in vitro and in vivo. These observations were associated with cell cycle arrest and increased apoptosis and autophagy. Together, these data indicate BTK-p80 and BTK-p65 as novel HNSCC-associated oncogenes. Owing to the fact that abundant BTK expression is a characteristic feature of primary and metastatic HNSCC, targeting BTK activity appears as a promising therapeutic option for HNSCC patients.

Protein-Based Oncopanel as Addition to Target Sequencing in Head and Neck Squamous Cell Carcinoma to Individualize Treatment Decisions

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous group of cancers and patients have limited therapy options if primary treatment fails. Therefore, additional information about the biology of the tumor is essential. Here we performed a feasibility study of concurrently applying two precision diagnostic tools in a consecutive series of HNSCC patients. We analyzed tumor samples of 31 patients using a genomic (oncomine) and a proteomic, immunohistochemical approach (oncopanel) and compared the result, also in the focus on their overlapping therapeutical targets. We found no strong correlation between the two approaches and observed a higher proportion of marker expression for the immunohistochemical panel. However, both panels show in our HNSCC cohort distinct patterns with druggable targets. The data suggest that both approaches complement one another and can be applied side-by-side to identify the best targets for the development of individual treatment options for HNSCC patients.

[Centralization, Specialization, and Outpatient Care for Head and Neck Tumor Patients]

Demographically, the German population is aging and becoming more morbid. At the same time, urbanization trends, medical overcapacities, and increasing care costs are being observed in association with a tight healthcare budget. Centralization, specialization, and outpatient care are intended to provide a remedy and can be controlled by modifications to remuneration. This upheaval poses new challenges for patients and physicians, which were analyzed exemplarily at the Head and Neck Tumor (HNC) Center of the University Hospital Ulm. This is a retrospective, monocentric cohort study on the development of patient volume, catchment area, treatment modality, and demographics including 2070 HNC patients at the ENT clinic between the years 2011 and 2020. It was observed that the number (new diagnoses 2011: 134 vs. 2020: 204) and the average age (2011: 61.5 years vs. 2020: 65.8 years; p < 0.0001) of HNC patients increased over time. In addition, patients tended to travel longer distances (2011: 54.4 km vs. 2020: 64.4 km; p = 0.05). At the same time, the mean number of consultations and treatments per patient per 5-year follow-up interval grew (at initial diagnosis in 2011: 7.8 vs. 2016: 10.4; p = 0.0003), with the proportion of outpatient contacts increasing from 58.9 % to 62.4 % (p = 0.09) from 2011 to 2020. Accordingly, clinical centers are expected to become more important in the care of HNC patients as the healthcare system becomes more specialized, and centralized with a growing outpatient setting. The following consequences for patient care should be considered in restructuring strategies.

Comparison of plasma- and saliva-derived exosomal miRNA profiles reveals diagnostic potential in head and neck cancer

Background: Head and neck squamous cell carcinomas (HNSCC) lack tumor-specific biomarkers. Exosomes from HNSCC patients carry immunomodulatory molecules, and correlate with clinical parameters. We compared miRNA profiles of plasma- and saliva-derived exosomes to reveal liquid biomarker candidates for HNSCC.

Methods: Exosomes were isolated by differential ultracentrifugation from corresponding plasma and saliva samples from 11 HNSCC patients and five healthy donors (HD). Exosomal miRNA profiles, as determined by nCounter^® SPRINT technology, were analyzed regarding their diagnostic and prognostic potential, correlated to clinical data and integrated into network analysis.

Results: 119 miRNAs overlapped between plasma- and saliva-derived exosomes of HNSCC patients, from which 29 tumor-exclusive miRNAs, associated with TP53, TGFB1, PRDM1, FOX O 1 and CDH1 signaling, were selected. By intra-correlation of tumor-exclusive miRNAs from plasma and saliva, top 10 miRNA candidates with the strongest correlation emerged as diagnostic panels to discriminate cancer and healthy as well as potentially prognostic panels for disease-free survival (DFS). Further, exosomal miRNAs were differentially represented in human papillomavirus (HPV) positive and negative as well as low and high stage disease.

Conclusion: A plasma- and a saliva-derived panel of tumor-exclusive exosomal miRNAs hold great potential as liquid biopsy for discrimination between cancer and healthy as well as HPV status and disease stage. Exosomal miRNAs from both biofluids represent a promising tool for future biomarker studies, emphasizing the possibility to substitute plasma by less-invasive saliva collection.

Cargo and Functional Profile of Saliva-Derived Exosomes Reveal Biomarkers Specific for Head and Neck Cancer

Background

Exosomes contribute to immunosuppression in head and neck squamous cell carcinoma (HNSCC), a tumor entity which lacks specific tumor biomarkers. Plasma-derived exosomes from HNSCC patients correlate with clinical parameters and have potential as liquid biopsy. Here, we investigate the cargo and functional profile of saliva-derived exosomes from HNSCC patients and their potential as non-invasive biomarkers for disease detection and immunomodulation.

Methods

Exosomes were isolated from saliva of HNSCC patients (n = 21) and healthy donors (HD, n = 12) by differential ultracentrifugation. Surface values of immune checkpoints and tumor associated antigens on saliva-derived exosomes were analyzed by bead-based flow cytometry using CD63 capture. Upon co-incubation with saliva-derived exosomes, activity and proliferation of T cells were assessed by flow cytometry (CD69 expression, CFSE assay). Adenosine levels were measured by mass spectrometry after incubation of saliva-derived exosomes with exogenous ATP. miRNA profiling of saliva-derived exosomes was performed using the nCounter^® SPRINT system.

Results

Saliva-derived, CD63-captured exosomes from HNSCC patients carried high amounts of CD44v3, PDL1 and CD39. Compared to plasma, saliva was rich in tumor-derived, CD44v3⁺ exosomes and poor in hematopoietic cell-derived, CD45⁺ exosomes. CD8⁺ T cell activity was attenuated by saliva-derived exosomes from HNSCC patients, while proliferation of CD4⁺ T cells was not affected. Further, saliva-derived exosomes produced high levels of immunosuppressive adenosine. 62 HD- and 31 HNSCC-exclusive miRNAs were identified. Samples were grouped in "Healthy" and "Cancer" based on their saliva-derived exosomal miRNA profile, which was further found to be involved in RAS/MAPK, NF-κB complex, Smad2/3, and IFN-α signaling.

Conclusions

Saliva-derived exosomes from HNSCC patients were enriched in tumor-derived exosomes whose cargo and functional profile reflected an immunosuppressive TME. Surface values of CD44v3, PDL1 and CD39 on CD63-captured exosomes, adenosine production and the miRNA cargo of saliva-derived exosomes emerged as discriminators of disease and emphasized their potential as liquid biomarkers specific for HNSCC.

Pathologic response after induction chemo-immunotherapy with single or double immune checkpoint inhibition in locally advanced head and neck squamous cell carcinoma (HNSCC): Expansion cohorts of the CheckRad-CD8 trial

6064

Background: Targeting the immune checkpoint CTLA-4 in addition to PD-1/PD-L1 alone did not increase efficacy in HNSCC, whereas this has not been studied in combination with chemotherapy. Induction chemo-immunotherapy followed by pathologic response-based patient selection for chemotherapy-free radioimmunotherapy was efficient in locally advanced HNSCC (J Immunother Cancer. 2022 Jan;10(1):e003747). The expansion cohorts of the CheckRad-CD8 trial studied safety and efficacy of induction chemo-immunotherapy with increased dose or without CTLA-4 inhibition. Methods: Patients with previously untreated stage III-IVB (AJCC 8th edition) HNSCC were eligible for this multicenter phase II trial. Induction chemo-immunotherapy of the main cohort (MC) consisted of a single cycle of cisplatin 30mg/m² d1-3, docetaxel 75mg/m² d1, durvalumab 1500mg fix dose d5 and tremelimumab 75mg fix dose d5. Patients in expansion cohort 1 (EC1) received this combination with high dose tremelimumab 300mg fix dose d5 and patients in expansion cohort 2 (EC2) received no tremelimumab. In EC1 and EC2 prophylactic G-CSF was recommended. Patients with at least 20% increase of intratumoral CD8+ immune cell density or pathological complete response (pCR) in the re-biopsy entered chemotherapy-free radioimmunotherapy up to a total dose of 70Gy. The current analysis focuses on toxicity and pathologic response after induction chemo-immunotherapy. Results: Between Sep 2018 and Sep 2021, 80 patients were enrolled in the MC (one excluded), 20 in EC1 and 20 in EC2 (one excluded) subsequently. In the MC, EC1 and EC2 a total of 56%, 50%, 58% were stage IV and 29%, 30%, 26% had p16 positive oropharyngeal tumors. Baseline median intratumoral CD8+ immune cell density was 395/mm², 505/mm² and 763/mm² in MC, EC1 and EC2. After induction chemo-immunotherapy 41 (52%), 12 (60%) and 11 (58%) of the patients had pCR in the re-biopsy in MC, EC1 and EC2. Patients with residual tumor after induction therapy had a median intratumoral CD8+ immune cell density of 670/mm², 781/mm² and 1605/mm², which was a median increase by factor 3.0, 2.1 and 4.8 in the corresponding patients’ tissue samples. In the cohorts MC, EC1 and EC2 the overall rate of grade 3-4 adverse events per patient was 1.38, 1.35 and 0.58. The corresponding rate of non-hematologic adverse events per patient was 0.84, 0.95 and 0.37, respectively. Conclusions: Neither increase of tremelimumab dosage nor its omission did significantly affect pathologic response to induction chemo-immunotherapy with cisplatin/ docetaxel/ durvalumab. Non-hematologic toxicity was slightly increased for high dose tremelimumab and clearly decreased without tremelimumab. The role of concomitant administration of tremelimumab with radiotherapy cannot be assessed until the final study analysis. Clinical trial information: NCT03426657.

Plasma-derived exosomes as biomarkers for therapy monitoring in head and neck cancer patients treated with surgery and (chemo)radiotherapy

Background

Head and neck squamous cell carcinomas (HNSCC) are highly immunosuppressive and aggressive malignancies. Exosomes are small extracellular vesicles that mediate intercellular communication. HNSCC patients have a significantly higher exosome load compared to healthy donors. Here, we evaluated the potential of plasma-derived exosomes as biomarkers for therapy monitoring in advanced HNSCC treated with conventional therapy.

Methods

Plasma from 17 HNSCC patients was collected before, during, and after treatment by surgery with adjuvant (chemo)radiation and at time of recurrence. Total exosomal protein (TEP) of exosomes was measured to estimate exosome load. Flow cytometry was used to evaluate relative fluorescence intensity (RFI) of tumor-associated and immunoregulatory proteins on exosomes. Effects of exosomes on CD8+ T cells and adenosine production by CD39+ T cells was assessed by flow cytometry and mass spectrometry.

Results

TEP levels and tumor-derived exosomes varied during and after therapy with an overall decrease in the tumor-free follow up but with an increase at time of recurrence. RFI values of immune checkpoints on exosomes, their potential for T cell inhibition, and adenosine production changed during and after therapy. Recurrent patients showed a different immunoinhibitory profile compared to disease-free patients. Exosomal PD-L1 emerged as the earliest discriminator for treatment failure and disease-free survival.

Conclusions

Plasma-derived exosomes from HNSCC patients emerge as promising non-invasive biomarkers for early detection of treatment failure. These exosomes can accurately inform about changes in patients’ immune status and may alert of impeding recurrence.

Changes in Gene Expression Patterns in the Tumor Microenvironment of Head and Neck Squamous Cell Carcinoma Under Chemoradiotherapy Depend on Response

Chemoradiotherapy (CRT) is a standard treatment for advanced head and neck squamous cell carcinoma (HNSCC). Unfortunately, not all patients respond to this therapy and require further treatment, either salvage surgery or palliative therapy. The addition of immunotherapy to CRT is currently being investigated and early results describe a mixed response. Therefore, it is important to understand the impact of CRT on the tumor microenvironment (TME) to be able to interpret the results of the clinical trials. Paired biopsies from 30 HNSCC patients were collected before and three months after completion of primary CRT and interrogated for the expression of 1392 immune- and cancer-related genes. There was a relevant difference in the number of differentially expressed genes between the total cohort and patients with residual disease. Genes involved in T cell activation showed significantly reduced expression in these tumors after therapy. Furthermore, gene enrichment for several T cell subsets confirmed this observation. The analysis of tissue resident memory T cells (T_RM) did not show a clear association with impaired response to therapy. CRT seems to lead to a loss of T cells in patients with incomplete response that needs to be reversed. It is not clear whether the addition of anti-PD-1 antibodies alone to CRT can prevent treatment failure, as no upregulation of the targets was measurable in the TME.

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

Simple Summary

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

Abstract

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

Differential Requirement of Vav Proteins for Btk-dependent and –Independent Signaling During B Cell Development

Btk and Vav proteins are all components of the signalosome that builds upon B cell receptor (BCR) activation. However, the role of Vav proteins within the signalosome is quite complex and not yet fully understood. Until now, studies of these have focused predominantly on a deficiency of Vav proteins alone or in combination with other Vav protein family members. Since a physical association of Btk with Vav was shown previously, we asked whether these molecules lie in the same or independent signaling pathways. By analyzing Vav1 and Vav3 single knock-out mice and generating double-knock-out animals deficient for either Vav1 or Vav3 and Btk, we observed, in line with previous publications, no severe B cell developmental defects when either Vav1 or Vav3 alone are not expressed. However, a simultaneous deficiency of Btk together with either Vav1 or Vav3 leads to a severe reduction of splenic B cells, which exhibit an immature phenotype. B cell developmental defects of Btk/Vav1-double deficient mice in the periphery were more severe than those observed in Btk-single-deficient animals. Additionally, morphological changes in splenic microarchitecture were observed in double- but also in single-knock-out mutants. These observations were accompanied by reduced BCR-induced Ca²⁺ mobilization, proliferation, germinal center formation and immunoglobulin secretion. Although deletion of Btk alone impaired Ca²⁺ mobilization upon BCR activation, the defect was even more severe when Vav1 or Vav3 were also mutated, indicating that Btk and the Vav proteins act in separate pathways that converge on Ca2+ signaling. In vitro ASC differentiation suggests that both B and T cells contribute to the observed phenotype of a Btk/Vav-double deficiency. Our results show that Vav proteins and Btk are both components of the BCR-activated signalosome but control separate signaling pathways important for B cell development.

[Immunotherapy of head and neck cancer : Highlights of the ASCO and ESMO annual meetings 2021]

BACKGROUND

This year's American Society of Clinical Oncology (ASCO) meeting included interesting data on first-line therapy of nasopharyngeal carcinomas with PD‑1 inhibitors and on checkpoint inhibition in various clinical constellations. At the European Society of Medical Oncology (ESMO) meeting, the results of the CheckMate-651 study were presented.

MATERIALS AND METHODS

All abstracts and presentations from the ASCO and ESMO meetings 2021 on immunotherapy in head and neck cancer (HNSCC) were evaluated for their relevance. The most interesting studies are elaborated upon herein.

RESULTS

Studies on locally advanced HNSCC showed an improved response after neoadjuvant pembrolizumab administration. A second cycle did not improve the response rate, but the proportion of patients with a good response was almost doubled. The CheckRad CD8 study showed an improvement in progression-free survival by induction chemoimmunotherapy with tremelimumab and durvalumab followed by stratification according to the CD8 immune cell infiltrate. Two studies were presented on first-line treatment of recurrent/metastatic nasopharyngeal carcinomas. Chemoimmunotherapy showed a higher response rate and prolonged progression-free survival with a similar adverse event profile. In recurrent/metastatic HNSCC, the CheckMate 651 study showed an increased duration of response with nivolumab and ipilimumab and higher response rates than pembrolizumab alone. The primary endpoints for overall survival were not achieved.

CONCLUSION

PD‑1 inhibition has great potential to change the therapeutic landscape for nasopharyngeal carcinomas in the future. In HNSCC, CD8 tumor infiltrate presents a promising predictive marker for selecting patients who can benefit from radioimmunotherapy. The combination of nivolumab and ipilimumab did not improve overall survival in palliative first-line therapy; thus, no change in the current standard is expected.

Induction chemoimmunotherapy followed by CD8+ immune cell-based patient selection for chemotherapy-free radioimmunotherapy in locally advanced head and neck cancer

PURPOSE

The first aim of the trial is to study feasibility of combined programmed death protein ligand 1/cytotoxic T-lymphocyte-associated protein 4 inhibition concomitant to radiotherapy. In addition, efficacy of the entire treatment scheme consisting of induction chemoimmunotherapy followed by chemotherapy-free radioimmunotherapy (RIT) after intratumoral CD8 +immune cell-based patient selection will be analyzed.

METHODS

Patients with stage III-IVB head and neck squamous cell carcinoma were eligible for this multicenter phase II trial. Treatment consisted of a single cycle of cisplatin 30 mg/m² days 1-3, docetaxel 75 mg/m² day 1, durvalumab 1500 mg fix dose day 5 and tremelimumab 75 mg fix dose day 5. Patients with increased intratumoral CD8 +immune cell density or pathological complete response (pCR) in the rebiopsy entered RIT up to a total dose of 70 Gy. Patients received further three cycles of durvalumab/tremelimumab followed by eight cycles of durvalumab mono (every 4 weeks). The intended treatment for patients not meeting these criteria was standard radiochemotherapy outside the trial. Primary endpoint was a feasibility rate of patients entering RIT to receive treatment until at least cycle 6 of immunotherapy of ≥80%.

RESULTS

Between September 2018 and May 2020, 80 patients were enrolled (one excluded). Out of these, 23 patients had human papilloma virus (HPV)-positive oropharyngeal cancer. Median follow-up was 17.2 months. After induction chemoimmunotherapy 41 patients had pCR and 31 had increased intratumoral CD8 +immune cells. Of 60 patients entering RIT (primary endpoint cohort), 10 experienced imiting toxic (mainly hepatitis) and four discontinued for other reasons, resulting in a feasibility rate of 82%. The RIT cohort (n=60) had a progression-free survival (PFS) rate at one and 2 years of 78% and 72%, respectively, and an overall survival rate at one and 2 years of 90% and 84%, respectively. Patients with HPV-positive oropharyngeal cancers had greater benefit from RIT with a 2-year PFS rate of 94% compared with 64% for HPV-negative oropharyngeal cancers and other locations. In the entire study cohort (n=79) the 2-year PFS rate was 68% (91% for HPV-positive oropharynx vs 59% for others). Toxicity grade 3-4 mainly consisted of dysphagia (53%), leukopenia (52%) and infections (32%).

CONCLUSIONS

The trial met the primary endpoint feasibility of RIT. Induction chemo-immunotherapy followed by chemotherapy-free RIT after intratumoral CD8 +immune cell-based patient selection has promising PFS.

TRIAL REGISTRATION NUMBER

The trial was registered with ClinicalTrials.gov (identifier: NCT03426657). The trial was conducted as investigator-sponsored trial (IST).

Changes in circulating exosome molecular profiles following surgery/(chemo)radiotherapy: early detection of response in head and neck cancer patients

BACKGROUND

Head and neck cancers (HNSCC) are highly immunosuppressive. Plasma-derived exosomes of HNSCC patients carry immunomodulatory molecules, and their cargo correlates with clinical parameters. Here, we evaluated the exosomal molecular profile for early detection of treatment failure in locally advanced HNSCC patients treated with conventional therapy.

METHODS

Plasma from 17 HNSCC patients was collected before, during, and after treatment by surgery with adjuvant (chemo)radiation and at recurrence. Exosomes were isolated by size-exclusion chromatography. Total exosomal protein (TEP) was used to estimate exosome load and on-bead flow cytometry to evaluate relative fluorescence intensity (RFI) of tumour-associated and immunoregulatory proteins on exosomes. Exosomal effects on the activity of and adenosine production by T cells was assessed by flow cytometry and mass spectrometry.

RESULTS

TEP and the ratio of tumour-/immune-cell-derived exosomes varied during and after therapy with an overall decrease in the tumour-free follow-up but an increase at recurrence. RFI values of immunoregulatory proteins on exosomes, their ability for T cell inhibition and adenosine production changed during and after therapy. PD-L1 was the earliest discriminator for treatment failure and disease-free survival.

CONCLUSIONS

Monitoring of plasma exosomes during therapy represents a promising opportunity for early detection of treatment failure and risk stratification to delay/avoid recurrence.

Primary results of the phase II CheckRad-CD8 trial: First-line treatment of locally advanced head and neck squamous cell carcinoma (HNSCC) with double checkpoint blockade and radiotherapy dependent on intratumoral CD8+ T-cell infiltration

6007

Background: Inhibition of the PD-1/PD-L1 pathway is efficient in recurrent/metastatic HNSCC. Targeting the immune checkpoint CTLA-4 may be synergistic to radiotherapy. This trial studies feasibility and efficacy of combined PD-L1/CTLA-4 blockade concomitant to induction chemotherapy and radiotherapy. Methods: Patients with previously untreated stage III-IVB (AJCC 8th edition) HNSCC were eligible for this multicenter phase II trial. Treatment consisted of a single cycle of cisplatin 30mg/m² d1-3, docetaxel 75mg/m² d1, durvalumab 1500mg fix dose d5 and tremelimumab 75mg fix dose d5. Patients with at least 20% increase of intratumoral CD8+ immune cell density or pathological complete response (pCR) in the re-biopsy (performed on d22-26) entered radio-immunotherapy (RIT) up to a total dose of 70Gy. Patients received further three cycles of durvalumab/tremelimumab (q4w, two concomitant and one subsequent) followed by eight cycles of durvalumab mono (q4w). Primary endpoint was a feasibility rate of patients entering RIT to receive treatment until at least cycle 6 of immunotherapy of ≥80% (i.e. dose limiting toxicity/DLT ≤20%; exclusion of patients with other reasons than DLT for treatment discontinuation; feasibility unacceptable if ≤65%). The calculated sample size was 57 patients to enter RIT. Main secondary endpoints were progression-free survival (PFS) and overall survival (OS). Results: Between Sep 2018 and Mai 2020, 80 patients were enrolled (one excluded). Median age was 60 years, 33 patients (42%) were current smokers, 43 patients (54%) had oropharyngeal tumors (53% p16 positive), 44 patients (56%) were stage IV. Median follow up was 12.5 months. After induction chemo-immunotherapy 41 patients had pCR and 31 an intratumoral CD8+ immune cell increase. Of 60 patients entering RIT (primary endpoint cohort), 10 received DLT and 4 discontinued for other reasons. The feasibility rate of the RIT cohort until cycle 6 was 82%, meeting the primary endpoint of ≥80% (95% confidence interval (CI), one-sided (lower boundary): 72%). The RIT cohort had a PFS rate at 1 year of 79% (CI 69-90%) and at 2 years of 73% (CI 61-87%) and an OS rate at 1 year of 89% (CI 81-98%) and at 2 years of 86% (CI 77-97%). The entire study cohort had a PFS rate at 1 year of 75% (CI 65-85%) and at 2 years of 68% (CI 58-81%) and an OS rate at 1 year of 86% (CI 78-95%) and at 2 years of 80% (CI 70-91%). Toxicity (treatment-related or un-related) ≥grade 3 appeared in 75 patients (95%) and mainly consisted of dysphagia (53%), leucopenia (48%) and infections (29%). DLT mainly consisted of hepatitis (10%). Conclusions: The trial met the primary endpoint feasibility. CD8+ T cell-based pathological patient selection after induction therapy identifies patients with promising PFS rates after chemotherapy-free RIT. Clinical trial information: nct03426657.

Performance of Different Diagnostic PD-L1 Clones in Head and Neck Squamous Cell Carcinoma

Background: The approval of immune checkpoint inhibitors in combination with specific diagnostic biomarkers presents new challenges to pathologists as tumor tissue needs to be tested for expression of programmed death-ligand 1 (PD-L1) for a variety of indications. As there is currently no requirement to use companion diagnostic assays for PD-L1 testing in Germany different clones are used in daily routine. While the correlation of staining results has been tested in various entities, there is no data for head and neck squamous cell carcinomas (HNSCC) so far.

Methods: We tested five different PD-L1 clones (SP263, SP142, E1L3N, 22-8, 22C3) on primary HNSCC tumor tissue of 75 patients in the form of tissue microarrays. Stainings of both immune and tumor cells were then assessed and quantified by pathologists to simulate real-world routine diagnostics. The results were analyzed descriptively and the resulting staining pattern across patients was further investigated by principal component analysis and non-negative matrix factorization clustering.

Results: Percentages of positive immune and tumor cells varied greatly. Both the resulting combined positive score as well as the eligibility for certain checkpoint inhibitor regimens was therefore strongly dependent on the choice of the antibody. No relevant co-clustering and low similarity of relative staining patterns across patients was found for the different antibodies.

Conclusions: Performance of different diagnostic anti PD-L1 antibody clones in HNSCC is less robust and interchangeable compared to reported data from other tumor entities. Determination of PD-L1 expression is critical for therapeutic decision making and may be aided by back-to-back testing of different PD-L1 clones.

Influence of travel burden on tumor classification and survival of head and neck cancer patients

PURPOSE

Cancer patients have to overcome various barriers to obtain diagnostics and treatment at head and neck cancer centers. Travel distance to a specialized hospital may result in psychosocial and financial distress, thus interfering with diagnostics, treatment, and follow-up care. In this study, we have aimed to analyze the association of travel distance with cTNM status, UICC stage at primary diagnosis, and survival outcomes of head and neck cancer (HNC) patients.

METHODS

We have analyzed data of 1921 consecutive HNC patients diagnosed between 2014 and 2019 at the head and neck cancer center of the Comprehensive Cancer Center Ulm (CCCU), Germany. Postal code-based travel distance calculation in kilometers, TNM status, and UICC stage were recorded at initial diagnosis. The assembly of travel distance-related groups (short, intermediate, long-distance) has been investigated. Moreover, group-related survival and recurrence analysis have been performed.

RESULTS

In contrast to observations from overseas, no association of travel distance and higher cTNM status or UICC stage at primary diagnosis has been observed. Furthermore, no significant differences for recurrence-free survival and overall survival by travel distance were detected.

CONCLUSION

In southern Germany, travel distance to head and neck cancer centers seems to be tolerable. Travel burden is not synonymous with travel distance alone but also involves sociodemographic, monetary, and disease-specific aspects as well as accessibility to proper infrastructure of transport and health care system.

Immune-Stimulatory Effects of Curcumin on the Tumor Microenvironment in Head and Neck Squamous Cell Carcinoma

Simple Summary

Head and neck squamous cell carcinoma has been shown to downregulate the host’s antitumor immune response as well as inherent anticancer immunity, inter alia, via increased activation of nuclear factor kappa of activated B-cells (NF-κB). The aim of this study is to examine curcumin’s effects on certain pro- and antitumoral chemokines via NF-κB, as well as the combined effects of curcumin and toll-like receptor 3 agonist Poly I:C on NF-κB and regulatory T-cell attraction. Furthermore, we compare curcumin with established NF-κB inhibitors caffeic acid phenethyl ester and BAY 11-7082. We demonstrate that curcumin has immune-modulating effects, with potent inhibition of the regulatory T-cell-attracting effects of Poly I:C. Therefore, curcumin presents an adjuvant that not only improves the effects of established therapies but also holds the potential to reduce negative side effects in tumor entities with increased NF-κB activation.

Abstract

Curcumin is known to have immune-modulatory and antitumor effects by interacting with more than 30 different proteins. An important feature of curcumin is the inhibition of nuclear factor kappa of activated B-cells (NF-κB). Here, we evaluate the potential of curcumin to reverse the epithelial to mesenchymal transition (EMT) of head and neck squamous cell carcinoma (HNSCC) cells as a part of tumor escape mechanisms. We examined the impact of curcumin on the expression of different pro- and antitumoral chemokines in ex vivo HNSCC tumor tissue and primary macrophage cultures. Further, we evaluated the combinatorial effect of curcumin and toll-like receptor 3 (TLR3) agonist Poly I:C (PIC) on NF-κB inhibition and regulatory T-cell (Treg) attraction. Mesenchymal markers were significantly reduced in cancer specimens after incubation with curcumin, with simultaneous reduction of key transcription factors of EMT, Snail, and Twist. Furthermore, a decrease of the Treg-attracting chemokine CCL22 was observed. Additionally, curcumin-related inhibition of NF-κB nuclear translocation was evident. The combination of PIC with curcumin resulted in further NF-κB inhibition, whereas PIC alone contrarily resulted in NF-κB activation. Furthermore, curcumin was more effective in inhibiting PIC-dependent NF-κB activation and Treg attraction compared to known NF-κB inhibitors BAY 11-7082 or caffeic acid phenethyl ester (CAPE). The presented results show, for the first time, the immune-modulating effects of curcumin in HNSCC, with potent inhibition of the Treg-attracting effects of PIC. Hence, curcumin presents a promising drug in cancer therapy as a supplement to already established treatments.

Increasing Mean Age of Head and Neck Cancer Patients at a German Tertiary Referral Center

BACKGROUND

The impact of demographic change on the age at diagnosis in German head and neck cancer (HNC) patients is unclear. Here we present an evaluation of aging trends in HNC at a tertiary referral center.

METHODS

Retrospective cohort study on aging trends at the initial diagnosis of newly diagnosed patients with HNC between 2004 and 2018 at the head and neck cancer center Ulm in relation to demographic data of the catchment area.

RESULTS

The study population consisted of 2450 individuals diagnosed with HNC with a mean age of 62.84 (±11.67) years. We observed a significant increase in annual incidence rates and mean age over time. Mean age among HNC patients increased significantly more than among the population in the catchment area. Whereas the incidence rate of patients <50 years did not change, the incidence of HNC patients aged ≥70 years increased the most. The mean patient age in the main tumor sites increased significantly. Surprisingly, HPV-positive patients were not younger than HPV-negative patients, but showed a non-significant trend towards a higher mean age (63.0 vs. 60.7 years).

CONCLUSIONS

Increasing incidence rates in older patients pose a challenge for health care systems. A nationwide study is needed to assess the dynamics and impact of aging on the incidence of HNC.

Correlation of HPV16 Gene Status and Gene Expression With Antibody Seropositivity and TIL Status in OPSCC

INTRODUCTION

Human papillomavirus 16 (HPV16) is the main cause of oropharyngeal squamous cell carcinoma (OPSCC). To date, the links between HPV16 gene expression and adaptive immune responses have not been investigated. We evaluated the correlation of HPV16 DNA, RNA transcripts and features of adaptive immune response by evaluating antibody isotypes against E2, E7 antigens and density of tumor-infiltrating lymphocytes (TIL).

MATERIAL AND METHODS

FFPE-tissue from 27/77 p16-positive OPSCC patients was available. DNA and RNA were extracted and quantified using qPCR for all HPV16 genes. The TIL status was assessed. Immune responses against E2 and E7 were quantified by ELISA (IgG, IgA, and IgM; 77 serum samples pre-treatment, 36 matched post-treatment).

RESULTS

Amounts of HPV16 genes were highly correlated at DNA and RNA levels. RNA co-expression of all genes was detected in 37% (7/19). E7 qPCR results were correlated with higher anti-E7 antibody (IgG, IgA) level in the blood. Patients with high anti-E2 IgG antibody (>median) had better overall survival (p=0.0311); anti-E2 and anti-E7 IgA levels had no detectable effect. During the first 6 months after treatment, IgA but not IgG increased significantly, and >6 months both antibody classes declined over time. Patients with immune cell-rich tumors had higher levels of circulating antibodies against HPV antigens.

CONCLUSION

We describe an HPV16 qPCR assay to quantify genomic and transcriptomic expression and correlate this with serum antibody levels against HPV16 oncoproteins. Understanding DNA/RNA expression, relationship to the antibody response in patients regarding treatment and outcome offers an attractive tool to improve patient care.

Prospective longitudinal study of immune checkpoint molecule (ICM) expression in immune cell subsets during curative conventional therapy of head and neck squamous cell carcinoma (HNSCC)

Programmed-death-1 (PD1) antibodies are approved for recurrent and metastatic head and neck squamous cell carcinoma. Multiple drugs targeting costimulatory and coinhibitory immune checkpoint molecules (ICM) have been discovered. However, it remains unknown how these ICM are affected by curative conventional therapy on different immune cell subsets during the course of treatment. In the prospective noninterventional clinical study titled "Immune Response Evaluation to Curative conventional Therapy" (NCT03053661), 22 patients were prospectively enrolled. Blood samples were drawn at defined time points throughout curative conventional treatment and follow-up. Immune cells (IC) from the different time points were assessed by multicolor flow cytometry. The following ICM were measured by flow cytometry: PD1, CTLA4, BTLA, CD137, CD27, GITR, OX40, LAG3 and TIM3. Dynamics of ICM expression were assessed using nonparametric paired samples tests. Significant changes were noted for PD1, BTLA and CD27 on multiple IC types during or after radiotherapy. Nonsignificant trends for increased expression of OX40 and GITR from baseline until the end of RT were observed on CD4 T cells and CD4⁺ CD39⁺ T cells. In patients with samples at recurrence of disease, a nonsignificant increase of TIM3 and LAG3 positive CD4⁺ CD39⁺ T cells was evident, accompanied by an increase of double positive cells for TIM3/LAG3. Potential future targets to be combined with RT in the conventional treatment and anti-PD1/PD-L could be BTLA agonists, or agonistic antibodies to costimulatory ICM like CD137, OX40 or GITR. The combination of cetuximab with CD27 agonistic antibodies enhancing ADCC or the targeting of TIM3/LAG3 may be another promising strategy.

Immune checkpoint expression in HNSCC patients before and after definitive chemoradiotherapy

BACKGROUND

Primary platinum-based chemoradiotherapy (CRT) remains the treatment of choice for nonresectable squamous cell carcinoma of the head and neck (HNSCC). Immune-checkpoint modulators are used as palliative therapy and studied in combination with definitive CRT. However, the immunological changes by CRT need yet to be understood.

METHODS

A cohort consisting of 67 paired tissue biopsies (N = 134) of HNSCC patients before and after CRT was created. The expression of PD-1, PD-L1, and CD27 of tumor and immune cells by immunohistochemistry was evaluated.

RESULTS

PD-L1 expression on immune cells of non-responders was significantly lower before CRT (P = .008). CD27 was expressed only on immune cells and not on cancer cells. A significant lower CD27-expression score was observed following CRT (P = .019).

CONCLUSIONS

Conventional CRT changes the expression of CD27 in the tumor microenvironment. Whether this is due to a loss of expression or a reduction of CD27+ cells must be evaluated in further analyses.

Safety and efficacy of single cycle induction treatment with cisplatin/docetaxel/ durvalumab/tremelimumab in locally advanced HNSCC: first results of CheckRad-CD8

Background

To determine safety and efficacy of single cycle induction treatment with cisplatin/docetaxel and durvalumab/tremelimumab in stage III-IVB head and neck cancer.

Methods

Patients received a single cycle of cisplatin 30 mg/m² on days 1–3 and docetaxel 75 mg/m² on day 1 combined with durvalumab 1500 mg fix dose on day 5 and tremelimumab 75 mg fix dose on day 5. Patients with pathologic complete response (pCR) in the rebiopsy after induction treatment or at least 20% increase of intratumoral CD8+ cell density in the rebiopsy compared with baseline entered radioimmunotherapy with concomitant durvalumab/tremelimumab. The objective of this interim analysis was to analyze safety and efficacy of the chemoimmunotherapy-induction treatment before radioimmunotherapy.

Results

A total of 57 patients were enrolled, 56 were treated. Median pretreatment intratumoral CD8+ cell density was 342 cells/mm². After induction treatment, 27 patients (48%) had a pCR in the rebiopsy and further 25 patients (45%) had a relevant increase of intratumoral CD8+ cells (median increase by a factor of 3.0). Adverse event (AE) grade 3–4 appeared in 38 patients (68%) and mainly consisted of leukopenia (43%) and infections (29%). Six patients (11%) developed grade 3–4 immune-related AE. Univariate analysis computed p16 positivity, programmed death ligand 1 immune cell area and intratumoral CD8+ cell density as predictors of pCR. On multivariable analysis, intratumoral CD8+ cell density predicted pCR independently (OR 1.0012 per cell/mm², 95% CI 1.0001 to 1.0022, p=0.016). In peripheral blood CD8+ cells, the coexpression of programmed death protein 1 significantly increased especially in patients with pCR.

Conclusions

Single cycle induction treatment with cisplatin/docetaxel and durvalumab/tremelimumab is feasible and achieves a high biopsy-proven pCR rate.

Analysis, identification and visualization of subgroups in genomics

Motivation

Cancer is a complex and heterogeneous disease involving multiple somatic mutations that accumulate during its progression. In the past years, the wide availability of genomic data from patients’ samples opened new perspectives in the analysis of gene mutations and alterations. Hence, visualizing and further identifying genes mutated in massive sets of patients are nowadays a critical task that sheds light on more personalized intervention approaches.

Results

Here, we extensively review existing tools for visualization and analysis of alteration data. We compare different approaches to study mutual exclusivity and sample coverage in large-scale omics data. We complement our review with the standalone software AVAtar (‘analysis and visualization of alteration data’) that integrates diverse aspects known from different tools into a comprehensive platform. AVAtar supplements customizable alteration plots by a multi-objective evolutionary algorithm for subset identification and provides an innovative and user-friendly interface for the evaluation of concurrent solutions. A use case from personalized medicine demonstrates its unique features showing an application on vaccination target selection.

Availability

AVAtar is available at: https://github.com/sysbio-bioinf/avatar

Contact

hans.kestler@uni-ulm.de, phone: +49 (0) 731 500 24 500, fax: +49 (0) 731 500 24 502

HNSCC: Tumour Antigens and Their Targeting by Immunotherapy

Head and neck squamous cell carcinomas (HNSCC) are a heterogeneous group of malignant tumours typically caused by alcohol and tobacco consumption, although an increasing number of HNSCC arise due to persistent infection with high-risk human papilloma virus (HPV). The treatment of HNSCC remains challenging, and the first-line setting is focused on surgery and chemoradiotherapy. A substantial proportion of HNSCC patients die from their disease, especially those with recurrent and metastatic disease. Among factors linked with good outcome, immune cell infiltration appears to have a major role. HPV-driven HNSCC are often T-cell rich, reflecting the presence of HPV antigens that are immunogenic. Tumour-associated antigens that are shared between patients or that are unique to an individual person may also induce varying degrees of immune response; studying these is important for the understanding of the interaction between the host immune system and the cancer. The resulting knowledge is critical for the design of better immunotherapies. Key questions are: Which antigens lead to an adaptive immune response in the tumour? Which of these are exploitable for immunotherapy? Here, we review the current thinking regarding tumour antigens in HNSCC and what has been learned from early phase clinical trials.

Peripheral Cytokine Levels Differ by HPV Status and Change Treatment-Dependently in Patients with Head and Neck Squamous Cell Carcinoma

Cytokines and immune mediators play an important role in the communication between immune cells guiding their response to infectious diseases or cancer. In this study, a comprehensive longitudinal analysis of serum cytokines and immune mediators in head and neck squamous cell carcinoma (HNSCC) patients was performed. In a prospective, non-interventional, longitudinal study, blood samples from 22 HNSCC patients were taken at defined time points (TP) before, during, and every 3 months after completion of (chemo)radio)therapy (CRT/RT) until 12 months after treatment. Serum concentrations of 17 cytokines/immune mediators and High-Mobility-Group-Protein B1 (HMGB1) were measured by fluorescent bead array and ELISA. Concentrations of sFas were significantly elevated during and after CRT/RT, whereas perforin levels were significantly decreased after CRT/RT. Levels of MIP-1β and Granzyme B differed significantly during CRT/RT by HPV status. Increased HMGB1 levels were observed at recurrence, accompanied by high levels of IL-4 and IL-10. The sFas increase and simultaneous perforin decrease may indicate an impaired immune cell function during adjuvant radiotherapy. Increased levels of pro-inflammatory cytokines in HPV+ compared to HPV- patients seem to reflect the elevated immunogenicity of HPV-positive tumors. High levels of HMGB1 and anti-inflammatory cytokines at recurrence may be interpreted as a sign of immune evasion.

Circulating Exosomes Inhibit B Cell Proliferation and Activity

(1) Background: Head and neck squamous cell carcinoma (HNSCC) is characterized by a distinctive suppression of the anti-tumor immunity, both locally in the tumor microenvironment (TME) and the periphery. Tumor-derived exosomes mediate this immune suppression by directly suppressing T effector function and by inducing differentiation of regulatory T cells. However, little is known about the effects of exosomes on B cells. (2) Methods: Peripheral B cells from healthy donors and HNSCC patients were isolated and checkpoint receptor expression was analyzed by flow cytometry. Circulating exosomes were isolated from the plasma of HNSCC patients (n = 21) and healthy individuals (n = 10) by mini size-exclusion chromatography. B cells from healthy individuals were co-cultured with isolated exosomes for up to 4 days. Proliferation, viability, surface expression of checkpoint receptors, and intracellular signaling were analyzed in B cells by flow cytometry. (3) Results: Expression of the checkpoint receptors PD-1 and LAG3 was increased on B cells from HNSCC patients. The protein concentration of circulating exosomes was increased in HNSCC patients as compared to healthy donors. Both exosomes from healthy individuals and HNSCC patients inhibited B cell proliferation and survival, in vitro. Surface expression of inhibitory and stimulatory checkpoint receptors on B cells was modulated in co-culture with exosomes. In addition, an inhibitory effect of exosomes on B cell receptor (BCR) signaling was demonstrated in B cells. (4) Conclusions: Plasma-derived exosomes show inhibitory effects on the function of healthy B cells. Interestingly, these inhibitory effects are similar between exosomes from healthy individuals and HNSCC patients, suggesting a physiological B cell inhibitory role of circulating exosomes.

Comparative effectiveness trial of transoral head and neck surgery followed by adjuvant radio(chemo)therapy versus primary radiochemotherapy for oropharyngeal cancer (TopROC)

BACKGROUND

For loco-regionally advanced, but transorally resectable oropharyngeal cancer (OPSCC), the current standard of care includes surgical resection and risk-adapted adjuvant (chemo) radiotherapy, or definite chemoradiation with or without salvage surgery. While transoral surgery for OPSCC has increased over the last decade for example in the United States due to transoral robotic surgery, this treatment approach has a long history in Germany. In contrast to Anglo-Saxon countries, transoral surgical approaches have been used frequently in Germany to treat patients with oro-, hypopharyngeal and laryngeal cancer. Transoral laser microsurgery (TLM) has had a long tradition since its introduction in the early 70s. To date, the different therapeutic approaches to transorally resectable OPSCC have not been directly compared to each other in a randomized trial concerning disease control and survival. The goal of this study is to compare initial transoral surgery to definitive chemoradiation for resectable OPSCC, especially with regards to local and regional control.

METHODS

TopROC is a prospective, two-arm, open label, multicenter, randomized, and controlled comparative effectiveness study. Eligible patients are ≥18 years old with treatment-naïve, histologically proven OPSCC (T1, N2a-c, M0; T2, N1-2c, M0; T3, N0-2c, M0 UICC vers. 7) which are amenable to transoral resection. Two hundred eighty patients will be randomly assigned (1:1) to surgical treatment (arm A) or chemoradiation (arm B). Standard of care treatment will be performed according to daily routine practice. Arm A consists of transoral surgical resection with neck dissection followed by risk-adapted adjuvant therapy. Patients treated in arm B receive standard chemoradiation, residual tumor may be subject to salvage surgery. Follow-up visits for 3 years are planned. Primary endpoint is time to local or locoregional failure (LRF). Secondary endpoints include overall and disease free survival, toxicity, and patient reported outcomes. Approximately 20 centers will be involved in Germany. This trial is supported by the German Cancer Aid and accompanied by a scientific support program.

DISCUSSION

This study will shed light on an urgently-needed randomized comparison of the strategy of primary chemoradiation vs. primary surgical approach. As a comparative effectiveness trial, it is designed to provide data based on two established regimens in daily clinical routine.

TRIAL REGISTRATION

NCT03691441 Registered 1 October 2018 - Retrospectively registered.

Immune Suppressive Effects of Plasma-Derived Exosome Populations in Head and Neck Cancer

Plasma-derived exosomes of head and neck squamous cell carcinoma (HNSCC) patients carry inhibitory factors mediating immune suppression. Separation of tumor-derived exosomes (TEX) and non-TEX may assist in a better understanding of their respective parental cells. Here, we evaluate the impact of TEX or hematopoietic-derived exosomes on immune suppression. We evaluated apoptosis in CD8+ T cells, conversion of CD4+ T cells to regulatory T cells (T_reg), and adenosine production by TEX, non-TEX, or total exosomes. Exosome protein cargo was significantly higher in total and CD45(−) exosomes from high stage compared to low stage patients. Furthermore, total and CD45(−) exosomes of high stage patients induced more apoptosis in CD8+ T cells than their low stage counterparts. CD69 suppression, a marker of reduced CD8+ T cell activation, was only mediated by CD45(−) exosomes. All fractions induced T_reg differentiation, defined by CD39 expression, but only CD45(−) exosomes showed a stage-dependent conversion. CD45(−) exosomes produced higher adenosine concentrations than CD45(+) exosomes, concluding that adenosine production measured in total exosomes mainly derives from TEX. The presented results show significant induction of immune suppression by TEX in HNSCC. This immunosuppressive effect supports the potential role of exosomes as liquid biomarkers for disease stage and level of immune suppression.

NF-κB and Its Role in Checkpoint Control

Nuclear factor-κB (NF-κB) has been described as one of the most important molecules linking inflammation to cancer. More recently, it has become clear that NF-κB is also involved in the regulation of immune checkpoint expression. Therapeutic approaches targeting immune checkpoint molecules, enabling the immune system to initiate immune responses against tumor cells, constitute a key breakthrough in cancer treatment. This review discusses recent evidence for an association of NF-κB and immune checkpoint expression and examines the therapeutic potential of inhibitors targeting either NF-κB directly or molecules involved in NF-κB regulation in combination with immune checkpoint blockade.

A multicenter phase II trial of the combination cisplatin/ docetaxel/durvalumab/tremelimumab as single-cycle induction treatment in locally advanced HNSCC (CheckRad-CD8 trial)

6519

Background: PD-1/PD-L1 inhibitors are efficient in head and neck squamous cell cancer (HNSCC). Combination with anti-CTLA4 agents may enhance anti-tumor activity compared to anti-PD-1/PD-L1 monotherapy in different tumor types. In the CheckRad-CD8 trial the typical induction treatment consisting of Cisplatin/Docetaxel was combined with Durvalumab/Tremelimumab. Patients with pathological complete response (pCR) in the re-biopsy after induction treatment or at least 20% increase of intratumoral CD8 density in the re-biopsy compared to baseline entered radioimmunotherapy with concomitant Durvalumab/Tremelimumab. Methods: In this prospective multicenter phase II trial, patients with HNSCC stage III-IVB received a single cycle of Cisplatin 30mg/m² d1-3, Docetaxel 75mg/m² d1, Durvalumab 1500mg fix dose d5 and Tremelimumab 75mg fix dose d5. Objectives of this interim analysis were to quantify the effect of the induction treatment on intratumoral CD8 density and the pCR rate and to generate safety data. Results: Between Sep 2018 and Dec 2019, 57 patients were enrolled. Median age was 59 years, 22 patients (37%) were current smokers, 27 patients (47%) had oropharyngeal tumors (52% p16 positive). The median pre-treatment intratumoral CD8 density was 335 CD8+ cells/mm². After induction treatment 27 patients (47%) had a pCR in the re-biopsy and further 25 patients (44%) had a relevant increase of intratumoral CD8+ cells (median increase by factor 3.0). Response according to RECIST criteria was CR in 1 (2%), PR in 19 (33%) and SD in 20 patients (35%) (17 patients not evaluable). Adverse events (AE) grade 3-4 appeared in 39 patients (68%) and mainly consisted of leucopenia (43%) and infections (28%). 6 patients (11%) developed grade 3-4 immune-related AEs. In multivariable analysis the intratumoral CD8 density was the only independently significant predictor of pCR (odds ratio 1.0013 per cell/mm², 95%-CI 1.00023-1.0023, p=0.017). 42 patients (74%) continued with Durvalumab/ Tremelimumab concomitant to radiotherapy. Conclusions: Single cycle induction treatment with Cisplatin/Docetaxel/Durvalumab/Tremelimumab is feasible and achieves a high pCR rate. CD8 density may have a predictive role for further treatment planning in locally advanced HNSCC. Clinical trial information: NCT03426657 .

CD3 and CD20 immune cell densities in primary tumors, lymph node metastasis, and recurrent disease samples of head and neck squamous cell carcinoma

6551

Background: Immune cell (IC) infiltrates in primary tumors (PT) have been identified as prognostic markers in head and neck squamous cell carcinoma (HNSCC). IC densities may differ among PT, lymph node metastasis (LNM) and recurrent disease (RD) and by primary disease site (oral cavity- OC, oropharynx- OP, hypopharynx- HP, larynx- L). Here, we compare CD3 and CD20 IC densities in PT, LNM and RD in paired samples from different disease sites and determine the prognostic impact of IC infiltrates. Methods: Tissue microarrays with 425 PT, 198 LNM and 46 RD samples--each in triplicate--were stained immunohistochemically for CD3 and CD20 in the same slide. Immune cell densities per mm2 were determined using a digital image analysis software (QuPath). Individual means were calculated from triplicates of each sample. IC infiltrates from different sample types (PT, LNM, RD) and primary tumor sites were compared using Kruskal-Wallis and Mann-Whitney-U tests. Paired samples were compared using Wilcoxon signed rank test. IC densities were classified as CD3 high/low and CD20 high/low for each primary tumor site using the individual median as a cut-off. Overall survival (OS) was calculated using the Kaplan-Meier method. P-values for each hypothesis were corrected using a false discovery rate of 5%. Results: CD3 and CD20 IC densities differed significantly by sample type (both p<0.0001) and primary site (CD3: p=0.012, CD20: p=0.0017). CD3 and CD20 densities were significantly lower in PT compared to LNM or in RD compared to PT and LNM. Paired samples (n=172) revealed a significantly higher CD3 and CD20 density (both p<0.0005) in LNM compared to PT, but no significant differences between PT and RD (n=28, p>0.05). CD3 densities were significantly higher than CD20 densities in all sample types. CD3high patients had the best prognosis in all sites except for OC (q<0.05) independent of CD20 status. In OC, CD3 density was not prognostic, but CD3low/CD20high patients had the worst OS compared to CD3low/CD20low and CD3high/CD20high or even CD3high/CD20low patients (p=0.018) who had the best prognosis. Conclusions: IC densities of CD3 and CD20 vary by sample type and primary site. Except for OC, in all sites the prognostic impact is determined by CD3high, whereas in OSCC only the combination of CD3 and CD20 IC densities achieves a good prognostic value. Interestingly, CD3low/CD20high patients have the worst overall survival in OC patients. Further work is needed to understand the interaction of B- and T cell infiltrates in the tumor, especially in OC.

Adenosine production in mesenchymal stromal cells in relation to their developmental status

BACKGROUND

Mesenchymal stromal cells (MSC) are multipotent progenitor cells found in the tumor microenvironment. They have an innate and regulatory immune activity, and they are able to produce immunosuppressive adenosine (ADO) via their ectonucleotidases CD39 and CD73. The present study explores ADO metabolism of MSC in relation to their developmental status.

METHODS

We analyzed MSC (n = 6), chondrogenic progenitor cells (CPC, n = 8), and chondrocytes (n = 8) for surface markers by flow cytometry. The ability to hydrolyze ATP and to produce ADO was tested by luminescence assays and mass spectrometry.

RESULTS

Significant differences in the surface marker expression of MSC, CPC, and chondrocytes were seen. While the expression of CD73 was observed to be the same on all cell types, the expression of the ectonucleotidase CD39 was significantly increased on MSC. Consequently, production of ADO was most abundant in MSC as compared with chondrocytes and CPC.

CONCLUSION

Mesenchymal stromal cells are potent producers of ADO and are, therefore, able to increase immunosuppression. As MSC differentiate into chondrocytes, they lose this ability and may take on other functions.

Age-related changes in T lymphocytes of patients with head and neck squamous cell carcinoma

Introduction

The number of aging cancer patients has increased continuously and will do so further in the future. The immune system of elderly people experiences critical changes over the time. Therefore, tumor-induced changes in the immune system are believed to differ in young and elderly cancer patients as well.

Methods

The effect of aging on the immune system was measured in peripheral blood lymphocytes (PBL) of healthy volunteers (n = 48, 21–84 yrs.) divided into three different age groups. Seventy years was set as a cut-off for defining subjects as elderly. Results were compared to two groups of adult cancer patients, which donated PBL and tumor infiltrating lymphocytes (TIL): young cancer patients (40–69 yrs.; blood: n = 13; TIL: n = 17) and elderly cancer patients (70–90 yrs.; blood: n = 20; TIL: n = 15) with head and neck squamous cell carcinoma (HNSCC). Frequencies and phenotypes of CD4⁺ and CD8⁺ T cells as well as regulatory T cells (T_reg) were assessed by flow cytometry.

Results

We observed lower frequencies of CD8⁺ cytotoxic T cells during aging in both groups. Frequencies of tumor infiltrating regulatory T cells were significantly higher than in the peripheral blood but showed a significant decline in older tumor patients. With increasing age, expression of immunosuppressive CD73 and CCR7 was lower and expression of PD1 elevated on peripheral T cells in healthy volunteers and tumor patients.

Conclusion

Immunosenescence takes place in healthy donors and cancer patients. Our results suggest that in elderly tumor patients, the immune system is impaired and the tumor-induced immune escape is less pronounced. The increased expression of PD1 implies the potential for effective immunotherapies in elderly, as treatment with checkpoint inhibitors could be more beneficial for elderly HNSCC patients.

Adenosine receptor 2B activity promotes autonomous growth, migration as well as vascularization of head and neck squamous cell carcinoma cells

Adenosine is a signaling molecule that exerts dual effects on tumor growth: while it inhibits immune cell function and thereby prevents surveillance by the immune system, it influences tumorigenesis directly via activation of adenosine receptors on tumor cells at the same time. However, the adenosine-mediated mechanisms affecting oncogenic processes particularly in head and neck squamous cell carcinomas (HNSCC) are not fully understood. Here, we investigated the role of adenosine receptor activity on HNSCC-derived cell lines. Targeting the adenosine receptor A2B (ADORA2B) on these cells with the inverse agonist/antagonist PSB-603 leads to inhibition of cell proliferation, transmigration as well as VEGFA secretion in vitro. At the molecular level, these effects were associated with cell cycle arrest as well as the induction of the apoptotic pathway. In addition, shRNA-mediated downmodulation of ADORA2B expression caused decreased proliferation. Moreover, in in vivo xenograft experiments, chemical and genetic abrogation of ADORA2B activity impaired tumor growth associated with decreased tumor vascularization. Together, our findings characterize ADORA2B as a crucial player in the maintenance of HNSCC and, therefore, as a potential therapeutic target for HNSCC treatment.