Lymphatic-preserving treatment sequencing with immune checkpoint inhibition unleashes cDC1-dependent antitumor immunity in HNSCC

Dendritic cell-based immunotherapy for head and neck squamous cell carcinoma: advances and challenges

Head and neck squamous cell carcinoma (HNSCC) is a prevalent cancer with poor response to conventional treatments such as surgery, chemotherapy and radiotherapy. Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of HNSCC, but many patients still exhibit poor responses due to insufficient T cell infiltration and impaired dendritic cell (DC) function within the tumor microenvironment. DCs are crucial for initiating anti-tumor immune responses, but their dysfunction in HNSCC leads to inadequate T cell activation and immune evasion. DC-based immunotherapy offers a promising approach to enhance ICIs therapy efficacy by improving DC function and enhancing T cell-mediated anti-tumor immune response. This review discusses the mechanisms underlying DC dysfunction in HNSCC, recent advances in DC-based immunotherapy, and the potential for combination therapies to overcome resistance to ICIs. Future strategies should focus on optimizing DC vaccines and developing personalized treatments to improve outcomes for HNSCC patients.

Nivolumab combined with induction chemotherapy and radiotherapy in nasopharyngeal carcinoma: A multicenter phase 2 PLATINUM trial

Severe toxicities caused by concurrent cisplatin are a critical problem in nasopharyngeal carcinoma (NPC) treatment. In this phase 2 multicenter PLATINUM trial (NCT03984357), we recruited 152 NPC patients who received 12-cycle nivolumab plus induction chemotherapy and radiotherapy without concurrent cisplatin. After a median follow-up of 43 months, the 3-year failure-free survival (FFS) was 88.5% (95% confidence interval [CI], 83.4%-93.8%) and the 3-year overall survival was 97.9%. An early clearance of Epstein-Barr virus (EBV) DNA after induction-phase treatment was associated with FFS benefit. Sixty (40.2%) and eight (5.2%) patients had acute and late grade 3-4 adverse events (AEs), respectively. Most patients had good tolerance to AE-associated frequency (68.0%-96.7%), severity (56.0%-98.6%), and interference (58.0%-98.0%); 86.7%-100.0% of quality-of-life domains showed either no clinically meaningful deterioration or a rapid recovery. Nivolumab plus induction chemotherapy and radiotherapy demonstrated efficacious anti-tumor activity, low toxicity, and favorable tolerability and quality-of-life for NPC patients.

Tumor-draining lymph nodes - friend or foe during immune checkpoint therapy?

The pivotal role of tumor-draining lymph nodes (TDLNs) in supporting antitumor immunity and serving as sites for cancer metastasis presents a clinical challenge: eliminate tumors while preserving antitumor immune responses. In this article, we explore the initiation of tumor-specific immune responses within lymph nodes (LNs), the immunocompromised microenvironment induced by tumors within LNs, and the crucial involvement of TDLNs in immunotherapy. Additionally, we examine the clinical prospects of modifying surgical procedures or therapy sequences to enhance the efficacy of cancer treatment.

Effects of Cisplatin on the Radiation Response and DNA Damage Markers in Peripheral Blood Lymphocytes Ex Vivo

Platinum-based radiochemotherapy is associated with hematologic side effects, impacting patient outcomes. However, the clinical mechanisms of cisplatin and its interaction with ionizing radiation (IR), including in biodosimetry for radiotherapy, have not yet been fully clarified. For this purpose, healthy donors' peripheral blood lymphocytes (PBLs) were pretreated with cisplatin in a pulse (1-4 h) or continuous (24 h) regimen followed by X-rays. DNA damage was assessed as DNA double-strand breaks using repair foci of γH2AX and 53BP1 after 0.5 h and 24 h in G1 PBLs and a proliferation-based cytokinesis-block micronucleus assay. Additionally, cell death and proliferation activity were measured. Unlike a 1 h pulse, a 24 h cisplatin pretreatment caused a concentration-dependent increase in cisplatin-induced foci while decreasing IR-induced foci, especially 24 h after irradiation. This was accompanied by increased apoptosis, with cisplatin and IR having additive effects. Both genotoxins alone caused a dose-dependent increase in micronuclei, while cisplatin significantly reduced binuclear cells, especially after the 24 h treatment, leading to lower micronuclei frequencies post-irradiation. Our results show that prolonged cisplatin exposure, even at low concentrations, impacts the vitality and division activity of PBLs, with significantly stronger effects post-irradiation. This has major implications and must be considered for the detection of DNA damage-associated biomarkers in PBLs used in clinical prediction or biodosimetry during radiotherapy.

Neoadjuvant Nivolumab Plus Chemotherapy Followed by Response-Stratified Chemoradiation Therapy in HPV-Negative Head and Neck Cancer: The DEPEND Phase 2 Nonrandomized Clinical Trial

Importance

Neoadjuvant immunotherapy in human papillomavirus (HPV)-negative locoregionally advanced (LA) head and neck squamous cell carcinoma (HNSCC) appears promising, yet its role in nonsurgical treatment for head and neck cancer remains undefined. Neoadjuvant nivolumab plus chemotherapy followed by response-stratified de-escalated chemoradiation therapy (CRT) in HPV-negative LA stage IVa/b HNSCC may improve treatment efficacy while reducing treatment-related toxic effects.

Objective

To determine the deep response rate and tolerability of neoadjuvant nivolumab plus chemotherapy followed by response-stratified CRT in nonvirally mediated stage IVa/b HNSCC.

Design, Setting, and Participants

In this investigator-initiated phase 2 nonrandomized clinical trial conducted at a single academic center, patients with stage IVa/b (American Joint Committee on Cancer Tumor Classification, 8th edition) HPV-negative LA HNSCC were enrolled between 2019 and 2022. Data were analyzed from February 2023 to January 2024.

Interventions

The DEPEND trial evaluated neoadjuvant nivolumab plus carboplatin and paclitaxel, followed by response-stratified CRT. Patients with 50% or greater reduction per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 received de-escalated CRT to 66 Gy with elimination of elective nodal volumes; patients with less than 50% reduction received standard CRT to 70 to 75 Gy. Adjuvant nivolumab was administered for 9 cycles.

Main Outcomes and Measures

The primary end point was deep response rate (DRR; 50% or greater shrinkage per RECIST version 1.1) following neoadjuvant nivolumab plus chemotherapy. Secondary end points included progression-free survival (PFS), overall survival (OS), locoregional control, and distant control. Exploratory end points included acute toxic effects in patients who received response-adapted de-escalated CRT.

Results

Of 36 included patients, 28 (78%) were male, and the median (range) age was 58.9 (27-77) years. All patients started treatment and were available for analysis. The median (range) follow-up was 20 (13-40) months. The primary end point was met, with a DRR following neoadjuvant nivolumab/chemotherapy of 53% (95% CI, 35-70). The objective response rate was 86% (95% CI, 71-95). A total of 19 received de-escalated CRT and 16 received standard CRT. PFS and OS at 2 years were 66% (95% CI, 34-76) and 73% (95% CI, 52-86), respectively. The most common treatment-emergent adverse events for de-escalated and standard CRT were mucositis (14 of 19 [74%] and 15 of 16 [94%], respectively), radiation dermatitis (13 of 19 [68%] and 14 of 16 [88%], respectively), and dry mouth (7 of 19 [37%] and 10 of 16 [63%], respectively).

Conclusions and Relevance

In this phase 2 nonrandomized clinical trial, neoadjuvant nivolumab/chemotherapy led to deep responses in 53% of patients with HPV-negative LA stage IVa/b HNSCC, and response-adapted de-escalated CRT led to favorable survival with lower acute toxic effects among deep responders.

Trial Registration

ClinicalTrials.gov Identifier: NCT03944915.

Impact of lymph node dissection during surgery on the efficacy of pembrolizumab in patients with metastatic urothelial carcinoma

OBJECTIVES

The impact of lymph node dissection (LND) on the efficacy of pembrolizumab in patients with urothelial carcinoma (UC) who develop metastasis after surgery remains unclear. This study aimed to investigate the efficacy of pembrolizumab in patients with metastatic UC who underwent primary tumor resection with LND.

PATIENTS AND METHODS

This retrospective study included patients who initially underwent radical surgery with or without LND for non-metastatic UC and later received pembrolizumab for recurrent lesions. Data were collected from a retrospective nationwide Japanese cohort study in patients with metastatic UC treated with pembrolizumab. The primary endpoints were overall response rate (ORR) and overall survival (OS). Multivariate analysis was performed to identify predictors of OS.

RESULTS

A total of 393 patients (273 [69.5%] underwent LND, and 120 (30.5%) did not) were included in this study. The ORRs for patients with and without LND were 30.8% and 27.3%, respectively (p = 0.460). No significant difference in OS was observed between the two groups (p = 0.471). Multivariate Cox regression analysis revealed that a neutrophil-to-lymphocyte ratio ≥3.0, Eastern Cooperative Oncology Group performance status ≥2, hemoglobin <11, and liver metastasis were associated with worse OS. However, LND was not associated with OS.

CONCLUSIONS

LND during primary tumor resection did not affect the efficacy of pembrolizumab in patients with metastatic UC.

The role and clinical significance of tumor-draining lymph nodes in tumor progression and immunotherapy

Tumor-draining lymph nodes (TDLNs) play a pivotal role in tumor growth and the immune response, activating immune cells such as CD8 + T cells and natural killer cells to combat tumors. However, tumors can subvert TDLNs to avoid immune attack. Initially, TDLNs stimulate a robust antitumor response, but as tumor evolve, they infiltrate with immunosuppressive cells that alter the TDLN environment and potentially promote metastasis. Immunotherapy, including immune checkpoint inhibitor (ICI), have emerged as a potential solution to this challenge by reconfiguring the TDLN environment to enhance immune responses and influence the immune status of the primary tumor. The integrity of the TDLNs is crucial for the efficacy of immunotherapy. Conventional surgery often removes TDLNs, but this may impede immune system function and the effectiveness of immunotherapy. It is therefore recommended that removal of TDLNs be considered after neoadjuvant treatment rather than before adjuvant treatment. Accurate identification of patients who require post-neoadjuvant TDLN removal and the determination of metastatic nodes is of paramount importance in tailoring treatment plans, optimizing of patient outcomes, and improving quality of life.

Unleashing the therapeutic potential of tumor-draining lymph nodes: spotlight on bladder cancer

Tumor-draining lymph nodes (TDLNs) are often involved during the metastasis of bladder cancer (BC), which is associated with a poor prognosis. Recent studies have shown that TDLNs are a major source of host anti-tumor immunity, which can impede tumor progression and favor tumor immunotherapy. However, during tumor progression, various tumor-derived mediators modulate the TDLN microenvironment, impairing their protective function. Ultimately, TDLNs provide the soil for the proliferation and dissemination of tumor cells. Therefore, surgical removal of TDLNs is commonly recommended in various solid tumors to prevent metastasis, but this poses significant challenges for leveraging TDLNs in immunotherapy. Additionally, lymph node dissection (LND) has not shown survival benefits in some tumors. Hence, the decision to remove TDLNs in oncological treatment needs to be reconsidered. Herein, we spotlight the TDLNs of BC and introduce how BC cells modulate stromal cells and immune cells to shape an immunosuppressive TDLN microenvironment for BC progression. We summarize the existing therapeutic strategies to reinvigorate anti-tumor immunity in TDLNs. Furthermore, we discuss whether to preserve TDLNs and the role of LND during oncological treatment.

Neck management in cT1-2N0 oral squamous cell carcinoma: Act or watchful wait?

The controversy over neck management for cT1-2N0 OSCC patients has persisted for two decades. While selective neck dissection (SND) has been deemed effective, only 30% of patients actually exhibit lymph node metastasis (LNM). SND-related complications, such as shoulder dysfunction and lymphedema, significantly impact patient quality of life, suggesting that 70% of patients may not benefit from SND. Current guidelines advocate observation, sentinel lymph node biopsy (SLNB), and SND, but the appropriate scenarios for each strategy need further exploration. Risk stratification assessment can inform treatment decisions in early-stage OSCC. This review explores histological risk factors, SLNB, gene expression profiles, and biomarkers for risk stratification. Additionally, we assess the potential value of postoperative radiotherapy (PORT) and immunotherapy, particularly immune checkpoint blockade (ICB), in cT1-2N0 OSCC. Risk-stratified approaches align with personalized medicine and precision surgery trends, while PORT and ICB may offer more reliable neck management options. This comprehensive review systematically synthesizes the past selection of therapeutic strategies for cT1-2N0 OSCC patients, alongside their respective strengths and limitations. We aspire to contribute to the optimization of treatment strategies for early-stage OSCC patients, ultimately enhancing both survival outcomes and quality of life.

Combination radiation and αPD-L1 enhance tumor control by stimulating CD8+ PD-1+ TCF-1+ T cells in the tumor-draining lymph node

Combination radiotherapy (RT) and αPD-L1 therapy has potential to enhance local and distant (abscopal) tumor control, however, clinical results in humans have been variable. Using murine melanoma models, we found RT + αPD-L1 increases intra-tumor progenitor CD8+ PD-1+ TCF-1+ T cells. This increase depends on trafficking of the PD-1+ TCF-1+ cells from the tumor-draining lymph node (TdLN) to the tumor. RT alone promotes the expansion and differentiation of the TdLN derived PD-1+ TCF-1+ cells into TIM-3+ GZMB+ TCF-1- effector-like cells in the tumor with further enhancement after the addition of αPD-L1. In the TdLN, combination therapy enriches for a novel PD-1+ TCF-1+ TOX- LY6A+ subset with expression of a type I interferon and migratory signature. This subset is able to traffic to the tumor and differentiate into TIM-3+ TCF-1- cells. Finally, we found that ablation of the PD-1+ TCF-1+ T cell population attenuates the enhanced tumor control observed with combination RT + αPD-L1. These results suggest that abscopal response failures may be secondary to impaired stimulation of TdLN CD8+ PD-1 + TCF-1+ T cells or an inability of PD-1+ TCF-1+ cells in the TdLN to traffic to the tumor.

FLASH radiotherapy spares lymphocytes in tumor-draining lymph nodes and increases infiltration of immune cells in tumors

Radiotherapy (RT) delivered at conventional dose rates (CONV) can both stimulate antitumor immune responses and inhibit these immune responses by depleting circulating lymphocytes. Given the observed normal tissue sparing associated with ultra-high dose rate (FLASH) RT, we hypothesized that FLASH RT may protect lymphocytes while increasing the immunogenicity of cancer cells. We irradiated cancer cell lines in vitro with FLASH RT or CONV RT and assessed immunogenic mRNA and protein expression. Both HPV-positive cell lines MEER and TC-1 showed upregulation of Calr, Hmgb1 , and cGAS-STING family members after FLASH RT but not after CONV RT in vitro . To assess changes in lymphocyte populations, we irradiated murine mEER tumors in syngeneic C57BL/6 mice with 27 Gy in 3 fractions of FLASH RT or CONV RT. In mice bearing FLASH irradiated tumors, tumor-draining lymph nodes contained greater numbers of CD8 + T cells (FLASH 1.7×10 4 vs 0.8×10 4 CONV; P <0.001) and CD4 + T cells (FLASH 2.3×10 4 vs CONV 1.2×10 4 ; P <0.001) after irradiation. FLASH RT was associated with increased numbers of activated CD44 + CD62L lo CD8 + and CD4 + lymphocytes. In irradiated tumors, FLASH RT was associated with increased CD8 + tumor-infiltrating lymphocytes, increased PD1 expression on these lymphocytes and increased PDL1 expression on macrophages. Compared with CONV RT, FLASH RT spared activated T cells in tumor-draining lymph nodes and in tumors but increased checkpoint inhibitor expression in tumors. These results suggest that FLASH RT may enhance antitumor immune responses by maintaining the immunogenic effects of RT while preserving lymphocyte numbers, which may be augmented with immune checkpoint blockade.

Significance

Radiation-induced lymphopenia is associated with poorer survival outcomes. New treatment approaches, like FLASH radiation therapy (FLASH RT), which reduce lymphopenia and enhance the antitumor response, could potentially lead to better outcomes for cancer patients.

Prognostic Implications of Lymph Node Status in Non-Small-Cell Lung Cancer Patients Before and After Neoadjuvant Chemoimmunotherapy: A Multicenter Retrospective Study

BACKGROUND

In patients with non-small-cell lung cancer (NSCLC) treated with neoadjuvant chemoimmunotherapy, lymph node (LN) status is classified as ypN0 and ypN+. However, ypN0 includes patients who either had LN metastasis before neoadjuvant therapy (cN+/ypN0) or those who never developed LN metastasis (cN0/ypN0). The prognostic implications of these different LN statuses are not well understood.

METHODS

A retrospective analysis was conducted on patients with NSCLC who underwent surgery after neoadjuvant chemoimmunotherapy at 4 centers in China from 2019 to 2022. Patients were grouped by their LN status into ``natural'' N0 (cN0/ypN0), ``downstaged'' N0 (cN+/ypN0), and ypN+ (cN+/ypN+).

RESULTS

Out of 527 initially enrolled patients, 186 met the inclusion criteria: 34 (18.3%) had ``natural'' N0, 95 (51.1%) had ``downstaged'' N0, and 57 (30.6%) had ypN+. The median follow-up was 24 months (11-64 months). Disease-free survival (DFS) and overall survival (OS) were significantly lower in ypN+ compared to ``natural'' N0 and ``downstaged'' N0 (DFS: P < .001; OS: P < .001). However, no significant difference in either DFS (P = .695) or OS (P = .814) were observed between ``natural'' N0 and ``downstaged'' N0. Subgroup analysis showed that the MPR/ypN0 group had significantly better DFS compared to the non-MPR/ypN0 (P = .008), MPR/ypN+ (P = .028), and non-MPR/ypN+ groups (P < .001). For OS, MPR/ypN0 group was significantly superior to non-MPR/ypN+ (P < .001) and showed a trend toward better OS than non-MPR/ypN0 (P = .067) and MPR/ypN+ (P = .067). Notably, no significant differences were observed in either DFS (P = .908) or OS (P = .943) between non-MPR/ypN0 and MPR/ypN+ groups. The non-MPR/ypN+ group had the poorest survival outcomes in both DFS and OS.

CONCLUSIONS

Achieving ypN0 status after neoadjuvant chemoimmunotherapy strongly predicts favorable outcomes in patients with NSCLC, regardless of pretreatment cN status. Combining MPR with LN status effectively differentiates patient prognoses.

IL-12-producing cytokine factories induce precursor exhausted T cells and elimination of primary and metastatic tumors

BACKGROUND

Curative responses to immunotherapy require the generation of robust systemic immunity with limited toxicity. Recruitment of T cell populations such as precursor exhausted T cells (Tpex) from lymphoid tissues to tumors is a hallmark of effective treatment. However, the ability to efficiently induce this recruitment is lacking in current immunotherapy approaches. Furthermore, systemic administration of immunotherapies frequently results in dose-limiting toxicities, yielding an inadequate therapeutic window for eliciting durable responses.

METHODS

In this investigation, we evaluated the safety and antitumor efficacy of locally administered interleukin 12 (IL-12) using a clinically translatable cytokine delivery platform (NCT05538624) to identify Tpex recruitment capabilities at tolerable cytokine doses.

RESULTS

We show IL-12 cytokine factories can effectively treat a broad spectrum of cancer types. Single-cell RNA sequencing data suggests that the antitumor efficacy seen in our studies was due to retinal pigmented epithelial cells-mIL12 treatment inducing differentiation of Tpex cells within the tumor microenvironment. When administered in combination with checkpoint therapy, IL-12 cytokine factory treatment generated systemic abscopal immunity, preventing subcutaneous tumor outgrowth in 8/9 mice with colorectal cancer and lung metastasis in mice with melanoma. Furthermore, this platform was well tolerated in a non-human primate without signs of toxicity.

CONCLUSIONS

Our new immunotherapy approach provides a robust strategy for inducing Tpex recruitment and systemic immunity against a range of solid peritoneal malignancies, many incurable with current immunotherapy strategies. Notably, these features were achieved using IL-12, and by leveraging our technology, we avoided the toxicities that have prevented the translation of IL-12 to the clinic. Our findings provide a strong rationale for the clinical development of IL-12 cytokine factories.

Predictors of Radiation Resistance and Novel Radiation Sensitizers in Head and Neck Cancers: Advancing Radiotherapy Efficacy

Radiation resistance in head and neck squamous cell carcinoma (HNSCC), driven by intrinsic and extrinsic factors, poses a significant challenge in radiation oncology. The key contributors are tumor hypoxia, cancer stem cells, cell cycle checkpoint activation, and DNA repair processes (homologous recombination and non-homologous end-joining). Genetic modifications such as TP53 mutations, KRAS mutations, EGFR overexpression, and abnormalities in DNA repair proteins like BRCA1/2 additionally affect radiation sensitivity. Novel radiosensitizers targeting these pathways demonstrate the potential to overcome resistance. Hypoxia-activated drugs and gold nanoparticles enhance the efficacy of radiotherapy and facilitate targeted distribution. Integrating immunotherapy, especially immune checkpoint inhibitors, with radiation therapy, enhances anti-tumor responses and reduces resistance. Epigenetic alterations, such as DNA methylation and histone acetylation, significantly influence radiation response, with the potential for sensitization through histone deacetylase inhibitors and non-coding RNA regulators. Metabolic changes linked to glucose, lipid, and glutamine metabolism influence radiosensitivity, uncovering new targets for radiosensitization. Human papillomavirus (HPV)-associated malignancies exhibit increased radiosensitivity relative to other tumors due to impaired DNA repair mechanisms and heightened immunogenicity. Furthermore, understanding the interplay between HPV oncoproteins and p53 functionality can enhance treatment strategies for HPV-related cancers. Using DNA damage response inhibitors (PARP, ATM/ATR), cell cycle checkpoint inhibitors (WEE1, CHK1/2), and hypoxia-targeted agents as radiosensitizing strategies exhibit considerable promise. Immunomodulatory approaches, including PD-1 and CTLA-4 inhibitors in conjunction with radiation, enhance anti-tumor immunity. Future directions emphasize personalized radiation therapy using genetics, sophisticated medication delivery systems, adaptive radiotherapy, and real-time monitoring. These integrated strategies seek to diminish radiation resistance and improve therapeutic efficacy in HNSCC.

Lowering Linker Symmetry to Access Zirconium Metal-Organic Frameworks for Inverse Alkane/Alkene Separations

Enriching the structural diversity of metal-organic frameworks (MOFs) is of great importance in developing functional porous materials with specific properties. New MOF structures can be accessed through the rational design of organic linkers with diverse geometric conformations, and their structural complexity can be enhanced by choosing linkers with reduced symmetry. Herein, a series of Zr-based MOFs with unprecedented topologies were developed through a linker desymmetrization and conformation engineering approach. A tritopic carboxylate linker with reduced symmetry and flexible triangular geometry was designed to construct three Zr-based MOFs (denoted as NU-57, NU-58, and NU-59) by modulating synthetic conditions. Notably, the conformational flexibility and reduced symmetry of the linker generated two unprecedented topologies in NU-58 and NU-59. Furthermore, solvent removal in NU-58 via thermal activation process produced missing linker defects. Finally, the adsorption behavior of these MOFs toward alkanes and alkenes was studied to gain insights into their structure-property relationships, which demonstrated that NU-57 and NU-58 exhibit unusual reverse selectivity for alkanes in alkane/alkene separations. Overall, this work highlights the rational design of linkers using a desymmetrization strategy as a powerful method to enrich the structural diversity of MOFs and to access novel MOFs with unique properties.

Antigenic cancer persister cells survive direct T cell attack

Drug-tolerant persister cancer cells were first reported fifteen years ago as a quiescent, reversible cell state which tolerates unattenuated cytotoxic drug stress. It remains unknown whether a similar phenomenon contributes to immune evasion. Here we report a persister state which survives weeks of direct cytotoxic T lymphocyte (CTL) attack. In contrast to previously known immune evasion mechanisms that avoid immune attack, antigenic persister cells robustly activate CTLs which deliver Granzyme B, secrete IFNγ, and induce tryptophan starvation resulting in apoptosis initiation. Instead of dying, persister cells paradoxically leverage apoptotic caspase activity to avoid inflammatory death. Furthermore, persister cells acquire mutations and epigenetic changes which enable outgrowth of CTL-resistant cells. Persister cell features are enriched in inflamed tumors which regressed during immunotherapy in vivo and in surgically resected human melanoma tissue under immune stress ex vivo. These findings reveal a persister cell state which is a barrier to immune-mediated tumor clearance.

Targeting YAP/TAZ-TEAD signaling as a therapeutic approach in head and neck squamous cell carcinoma

Genetic alterations in Hippo pathway and the consequent activation of YAP/TAZ-TEAD are frequently observed in HPV-negative head and neck squamous cell carcinoma (HNSCC) patients. These include loss-of-function mutation and/or copy number loss of FAT1, and amplification of YAP1 and WWTR1 (encoding TAZ), thus raising the possibility that HNSCC cells may be dependent on YAP/TAZ-TEAD-mediated transcriptional programs. In this regard, the recent development of small molecule TEAD inhibitors (smTEADi) provides an opportunity to therapeutically target Hippo pathway dysregulation in human malignancies. This prompted us to explore the potential benefit of pharmacologically targeting the YAP/TAZ-TEAD axis in this disease. Here, we provide the pre-clinical evidence for the antitumor activity of novel smTEADi, SW-682 in HPV-negative HNSCC. By the use of multiple complementary experimental approaches, including siRNA knockdown, expression of a genetically encoded TEAD inhibitor peptide (pTEADi), and SW-682, we revealed that disruption of YAP/TAZ-TEAD interaction suppresses YAP/TAZ-TEAD-dependent target gene transcription and growth of HNSCC tumors. HNSCC cells with genetic alterations in FAT1 were more sensitive to TEADi compared to FAT1-wild type cells. Mechanistically, TEADi suppressed cell cycle progression and promoted the expression of terminal differentiation gene programs, resulting in tumor growth inhibition. A HNSCC-specific TEADi target gene set was defined from RNA-seq data, which is highly expressed in HNSCC tissues and predicts poor prognosis of HPV-negative HNSCC patients. Our results underscore that YAP/TAZ-TEAD-mediated growth-promoting programs represent a vulnerability in HPV-negative HNSCC, thus providing a pre-clinical rationale for the future evaluation of YAP/TAZ-TEAD targeting strategies as a therapeutic approach for HPV-negative HNSCC patients.

Tumor and blood B-cell abundance outperforms established immune checkpoint blockade response prediction signatures in head and neck cancer

BACKGROUND

Immunotherapy has improved the outcomes for some patients with head and neck squamous-cell carcinoma (HNSCC). However, the low and variable response rates observed highlight the need for robust response biomarkers to select patients for treatment.

PATIENTS AND METHODS

We assembled and analyzed a large HNSCC dataset, encompassing 11 clinical cohorts including 1232 patient samples, spanning a variety of disease subtypes and immune checkpoint blockade (ICB) treatment types, tissue sources, data modalities, and timing of measurements. We conducted a comprehensive evaluation of the predictive power of various cell types, traditional biomarkers, and emerging predictors in both blood and tumor tissues of HNSCC patients.

RESULTS

Tumor B-cell infiltration emerged as a strong and robust predictor of both patient survival and ICB response. It outperformed all other established biomarkers of response to ICB, including the tertiary lymphoid structure signature and numerous T-cell-based signatures. B-cell infiltration was associated with a 'hot' antitumor microenvironment that promotes tumor eradication. Furthermore, B-cell levels in peripheral blood mononuclear cells (PBMCs) correlated strongly with tumor B-cell levels and demonstrated high predictive value for ICB response, with high odds ratios (≥7.8) in two independent clinical cohorts.

CONCLUSION

B-cell abundance, whether assessed in PBMCs or tumor tissues, is one of the strongest predictors of ICB response in HNSCC. For translation to patient care, measuring B-cell abundance in PBMCs via cytometry offers a practical and accessible tool for clinical decision making.

Proceedings of the National Cancer Institute Workshop on combining immunotherapy with radiotherapy: challenges and opportunities for clinical translation

Radiotherapy both promotes and antagonises tumour immune recognition. Some clinical studies show improved patient outcomes when immunotherapies are integrated with radiotherapy. Safe, greater than additive, clinical response to the combination is limited to a subset of patients, however, and how radiotherapy can best be combined with immunotherapies remains unclear. The National Cancer Institute-Immuno-Oncology Translational Network-Society for Immunotherapy of Cancer-American Association of Immunology Workshop on Combining Immunotherapy with Radiotherapy was convened to identify and prioritise opportunities and challenges for radiotherapy and immunotherapy combinations. Sessions examined the immune effects of radiation, barriers to anti-tumour immune response, previous clinical trial data, immunological and computational assessment of response, and next-generation radiotherapy-immunotherapy combinations. Panel recommendations included: developing and implementing patient selection and biomarker-guided approaches; applying mechanistic understanding to optimise delivery of radiotherapy and selection of immunotherapies; using rigorous preclinical models including companion animal studies; embracing data sharing and standardisation, advanced modelling, and multidisciplinary cross-institution collaboration; interrogating clinical data, including negative trials; and incorporating novel clinical endpoints and trial designs.

Response-Adaptive Surgical Timing in Neoadjuvant Immunotherapy Demonstrates Enhanced Pathologic Treatment Response in Head and Neck Squamous Cell Carcinoma

PURPOSE

We evaluated whether indoleamine 2,3-dioxygenase (IDO1) inhibitor (IDOi) BMS986205 + PD-1 inhibitor nivolumab enhanced T-cell activity and augmented immune-mediated antitumor responses in untreated, resectable head and neck squamous cell carcinoma (HNSCC). We employed response-adaptive surgical timing to identify responders to immunotherapy and enhance their response.

PATIENTS AND METHODS

Patients with HNSCC were 3:1 randomized to receive nivolumab with or without BMS986205 orally daily (NCT03854032). In the combination arm, BMS986205 was initiated 7 days prior to nivolumab. Patients were stratified by human papillomavirus (HPV) status. Response-adaptive surgical timing involved response assessment by radiographic criteria 4 weeks after treatment with nivolumab in both arms. Nonresponders underwent surgical resection, whereas responders received 4 more weeks of randomized therapy before surgery. Biomarker analysis utilized pathologic treatment response (pTR) and RNA sequencing.

RESULTS

Forty-two patients were enrolled, and the addition of IDOi to nivolumab did not result in greater rate of radiographic response (P = 0.909). Treatment was well tolerated, with only 2 (5%) patients experiencing grade 3 immune-related adverse events. The addition of IDOi augmented rates of pTR in patients with high baseline IDO1 RNA expression (P < 0.05). Response-adaptive surgical timing demonstrated reliability in differentiating pathologic responders versus nonresponders (P = 0.009). A pretreatment NK cell signature, PD-L1 status, and IFN-γ expression in the HPV- cohort correlated with response. The HPV+ cohort found B-cell and cancer-associated fibroblast signatures predictive of response/nonresponse.

CONCLUSIONS

Response-adaptive surgical timing enhanced treatment response. IDOi BMS986205 augmented pTR in patients with high IDO1 expression in baseline samples, indicating a need for identifying and targeting resistant nodes to immunotherapy. HPV status-dependent signatures predicting response to immunotherapy in HNSCC warrant further study.

Predictive Role of Lymph Node Germinal Centers in Postoperative Recurrence of Non-Small Cell Lung Cancer Treated With Immune Checkpoint Inhibitor Therapy

Introduction The germinal center (GC) in lymph nodes plays an important role in immune responses; however, their relevance to the effects of immune checkpoint inhibitor (ICI) remains unclear. The relationship between GC and ICI efficacy is investigated in this study. Materials and methods This investigation included 16 non-small cell lung cancer (NSCLC) patients with postoperative recurrence who were treated with immune checkpoint inhibitors (ICI) between January 2016 and April 2022. Patients were categorized into two groups based on the presence of GC in the lymph nodes. Additionally, the association between the number of lymph nodes dissected during pulmonary resection and ICI efficacy was evaluated. Results Sixteen patients were included with eight GC+ patients and eight GC- patients. The presence of GC positively influenced ICI efficacy, with the objective response rate (ORR) being significantly higher in the GC+ group (62.5%) compared to the GC- group (12.5%) (p=0.039). Disease control rate (DCR) was also more favorable in the GC+ group (100%) compared to the GC- group (50%) (p=0.021). Additionally, patients with fewer lymph nodes dissected at surgery had a better progression-free survival (median: 15.7 months) than those with more lymph nodes dissected (median: 7.4 months) (p=0.027). Conclusion GC in the lymph nodes can enhance the efficacy of ICI in treating NSCLC. Moreover, the number of dissected lymph nodes has emerged as a crucial prognostic factor that influences the effectiveness of treatment. These findings underscore the importance of considering lymph node characteristics in personalized ICI therapy for NSCLC.

The ending is not the end: Lymph node metastasis in oral squamous cell carcinoma

Lymph node metastasis is an important biological feature of oral squamous cell carcinoma, bearing poorly prognostic implications. However, the role of lymph node metastasis in cancer progression remains inconclusive. On the one hand, lymph nodes are pivotal sites for initiating specific immunity, which is crucial for maintaining antitumor immune response. On the other hand, they also serve as primary conduits for tumor metastasis, with lymph node colonization potentially inducing systemic immune dysfunction, thereby further promoting tumor progression. Considering this paradoxical role of lymph nodes, comprehending their impact on the primary tumor and immunity becomes paramount. Furthermore, leveraging these distinctive attributes of lymph nodes presents novel avenues for enhancing current therapeutic strategies against oral squamous cell carcinoma. This review summarizes the anatomical and molecular profiles of lymph node metastasis in oral squamous cell carcinoma, elucidating how lymphatic involvement compromises antitumor immunity, thus facilitating primary tumor and distant metastases. Additionally, it explores avenues for harnessing these mechanisms to optimize clinical interventions.

Trigger inducible tertiary lymphoid structure formation using covalent organic frameworks for cancer immunotherapy

The discovery of tertiary lymphoid structures (TLS) within tumor tissues provides a promising avenue to promote the efficacy of cancer immunotherapy. Yet, the lack of effective strategies to induce TLS formation poses a substantial obstacle. Thus, the exploration of potential inducers for TLS formation is of great interest but remains challenging. Here, inspired by the mechanism of artificially cultivated pearls, a covalent organic framework (COF) is employed to induce TLS formation. Single-cell sequencing analysis reveals that this is achieved by promotion of cytokine hypersecretion, which facilitates the maturation, proliferation, and migration of T and B cells, critical for triggering TLS formation. Furthermore, the efficacy of COF-mediated phototherapy in inducing TLS formation is validated in both the MC38 and 4MOSC1 female tumor models. Notably, a strong synergistic effect between COF-mediated phototherapy and αCTLA-4 is observed, resulting in the effective eradication of both primary and distant tumors, while also inhibiting tumor recurrence.

Cancer immunotherapy response persists after lymph node resection

Lymphatic transport facilitates the presentation of cancer antigens in tumor-draining lymph nodes (tdLNs), leading to T cell activation and the generation of systemic antitumor immune surveillance. Surgical removal of LNs to control cancer progression is routine in clinical practice. However, whether removing tdLNs impairs immune checkpoint blockade (ICB) is still controversial. Our analysis demonstrates that melanoma patients remain responsive to PD-1 checkpoint blockade after LN dissection. We were able to recapitulate the persistent response to ICB after complete LN resection in murine melanoma and mammary carcinoma models. Mechanistically, soluble antigen and antigen-carrying migratory dendritic cells are diverted to non-directly tumor draining LNs (non-tdLNs) after tdLN dissection. Consistently, robust ICB responses in patients with head and neck cancer after primary tumor and tdLN resection correlated with the presence of reactive LNs in distant areas. These findings indicate that non-tdLNs sufficiently compensate for the removal of direct tdLNs and sustain the response to ICB.

Response of Spontaneous Oral Tumors in Canine Cancer Patients Treated with Stereotactic Body Radiation Therapy (SBRT)

The objective of this study is describe outcome and toxicity for dogs with oral tumors, specifically oral malignant melanoma (OMM), squamous cell carcinoma (SCC), and soft tissue sarcoma (STS) after stereotactic body radiation therapy (SBRT). A single institution retrospective study was conducted. Outcomes were analyzed using Kaplan-Meier analysis and Cox proportional hazard analysis. Treatment responses at different time points were evaluated with Pearson's Chi-squared test to identify prognostic factors. Acute and late toxicities were recorded according to VRTOG criteria and were analyzed to identify risk factors. Adverse events other than acute and late toxicities were recorded. A total of 98 patients met the inclusion criteria (OMM n = 37; SCC n = 18; STS n = 43). The SBRT prescription was 1-6 fractions, with a total dose range of 12-40 Gy. Local progression-free survival (PFS) for OMM, SCC, and STS was 187, 253, and 161 days, respectively. Overall PFS was 152 days and median survival time (MST) was 270 days, with no statistical difference between tumor types. The presence of lymph node metastasis and the use of elective nodal irradiation (ENI) were associated with shorted PFS and MST. Severe acute toxicities to organs at risk affected 10/85 (11.8%) of patients. Osteoradionecrosis and oronasal fistula formation occurred in 23/81 (28.4%) of patients and was significantly associated with tumor type (SCC, P = 0.006). SBRT can be offered as a treatment option for oral tumors in dogs. Toxicities were common and warrant risk factor considerations and adjustments to current SBRT protocols.

A multi-institutional feasibility lead-in trial of lymphatic mapping with SPECT-CT for evaluating contralateral disease in lateralized oropharynx cancer using 99m-technetium sulfur colloid

BACKGROUND

Lymphatic mapping with SPECT-CT has been demonstrated to accurately define lymphatic drainage patterns in oropharyngeal cancer but there has yet to be a study demonstrating its feasibility across multiple institutions.

METHODS

Twelve adult patients with lateralized oropharyngeal carcinoma (T1-T3) who were planned for definitive or adjuvant radiotherapy without contralateral nodal disease underwent injection of 99-m technetium sulfur colloid followed by static planar lymphoscintigraphy to verify tracer migration, and SPECT-CT acquired at 30 ± 15 min (optional) and 3 h (±1 h) (mandatory time-point).

RESULTS

All 12 patients completed the study with 7/12 patients having the injections performed under local anesthetic and 5 patients requiring general anesthetic. There were no tracer migration failures and there were no serious adverse events or complications encountered. Four out of 12 patients (33%) showed contralateral drainage patterns.

CONCLUSIONS

Lymphatic mapping with SPECT-CT of lateralized oropharyngeal squamous cell carcinoma can be performed safely across multiple institutions.

Association of oropharyngeal cancer recurrence with tumor-intrinsic and immune-mediated sequelae of reduced genomic instability

Background

Limited understanding of the biology predisposing certain human papillomavirus-related (HPV+) oropharyngeal squamous cell carcinomas (OPSCCs) to relapse impedes therapeutic personalization. We aimed to identify molecular traits that distinguish recurrence-prone tumors.

Methods

50 HPV+ OPSCCs that later recurred (cases) and 50 non-recurrent controls matched for stage, therapy, and smoking history were RNA-sequenced. Groups were compared by gene set enrichment analysis, and select differences were validated by immunohistochemistry. Features discriminating groups were scored in each tumor using gene set variation analysis, and scores were evaluated for recurrence prediction ability.

Results

Cases downregulated pathways linked to anti-tumor immunity (FDR-adjusted p<.05) and contained fewer tumor-infiltrating lymphocytes (p<.001), including cytotoxic T-cells (p=.005). Cases also upregulated pathways related to cell division and other aspects of tumor progression. Upregulated and downregulated pathways were respectively used to define a tumor progression score (TPS) and immune suppression score (ISS) for each tumor. Correlation between TPS and ISS (r=.603, p<.001) was potentially explained by observed upregulation of DNA repair pathways in cases, which might enhance their progression directly and by limiting cytosolic DNA-induced inflammation. Accordingly, cases contained fewer double-strand breaks based on staining for phospho-RPA32 (p=.006) and γ-H2AX (p=.005) and downregulated pro-inflammatory components of the cytoplasmic DNA sensing pathway. A combined score derived from TPS and ISS optimized recurrence prediction and stratified survival in a manner generalizable to three external cohorts.

Conclusions

We provide novel evidence that limiting genomic instability makes tumor-intrinsic and immune-mediated contributions to HPV+ OPSCC recurrence risk, opening opportunities to detect and target this treatment-resistant biology.

Longitudinal Assessment of Tumor-Infiltrating Lymphocytes in Primary Breast Cancer Following Neoadjuvant Radiation Therapy

PURPOSE

Tumor-infiltrating lymphocytes (TILs) have prognostic significance in several cancers, including breast cancer. Despite interest in combining radiation therapy with immunotherapy, little is known about the effect of radiation therapy itself on the tumor-immune microenvironment, including TILs. Here, we interrogated longitudinal dynamics of TILs and systemic lymphocytes in patient samples taken before, during, and after neoadjuvant radiation therapy (NART) from PRADA and Neo-RT breast clinical trials.

METHODS AND MATERIALS

We manually scored stromal TILs (sTILs) from longitudinal tumor samples using standardized guidelines as well as deep learning-based scores at cell-level (cTIL) and cell- and tissue-level combination analyses (SuperTIL). In parallel, we interrogated absolute lymphocyte counts from routine blood tests at corresponding time points during treatment. Exploratory analyses studied the relationship between TILs and pathologic complete response (pCR) and long-term outcomes.

RESULTS

Patients receiving NART experienced a significant and uniform decrease in sTILs that did not recover at the time of surgery (P < .0001). This lymphodepletive effect was also mirrored in peripheral blood. Our SuperTIL deep learning score showed good concordance with manual sTILs and importantly performed comparably to manual scores in predicting pCR from diagnostic biopsies. The analysis suggested an association between baseline sTILs and pCR, as well as sTILs at surgery and relapse, in patients receiving NART.

CONCLUSIONS

This study provides novel insights into TIL dynamics in the context of NART in breast cancer and demonstrates the potential for artificial intelligence to assist routine pathology. We have identified trends that warrant further interrogation and have a bearing on future radioimmunotherapy trials.

Cell Identity and Spatial Distribution of PD-1/PD-L1 Blockade Responders

The programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) axis inhibits T cell activity, impairing anti-tumor immunity. Blocking this axis with therapeutic antibodies is one of the most promising anti-tumor immunotherapies. It has long been recognized that PD-1/PD-L1 blockade reinvigorates exhausted T (TEX) cells already present in the tumor microenvironment (TME). However, recent advancements in high-throughput gene sequencing and bioinformatic tools have provided researchers with a more granular and dynamic insight into PD-1/PD-L1 blockade-responding cells, extending beyond the TME and TEX populations. This review provides an update on the cell identity, spatial distribution, and treatment-induced spatiotemporal dynamics of PD-1/PD-L1 blockade responders. It also provides a synopsis of preliminary reports of potential PD-1/PD-L1 blockade responders other than T cells to depict a panoramic picture. Important questions to answer in further studies and the translational and clinical potential of the evolving understandings are also discussed.

Hepatocellular carcinoma-specific epigenetic checkpoints bidirectionally regulate the antitumor immunity of CD4 + T cells

Hepatocellular carcinoma (HCC) is a highly malignant tumor with significant global health implications. The role of CD4+ T cells, particularly conventional CD4+ T cells (Tconvs), in HCC progression remains unexplored. Furthermore, epigenetic factors are crucial in immune regulation, yet their specific role in HCC-infiltrating Tconv cells remains elusive. This study elucidates the role of MATR3, an epigenetic regulator, in modulating Tconv activity and immune evasion within the HCC microenvironment. Reanalysis of the scRNA-seq data revealed that early activation of CD4+ T cells is crucial for establishing an antitumor immune response. In vivo and in vitro experiments revealed that Tconv enhances cDC1-induced CD8+ T-cell activation. Screening identified MATR3 as a critical regulator of Tconv function, which is necessary for antitumour activity but harmful when overexpressed. Excessive MATR3 expression exacerbates Tconv exhaustion and impairs function by recruiting the SWI/SNF complex to relax chromatin in the TOX promoter region, leading to aberrant transcriptional changes. In summary, MATR3 is an HCC-specific epigenetic checkpoint that bidirectionally regulates Tconv antitumour immunity, suggesting new therapeutic strategies targeting epigenetic regulators to enhance antitumour immunity in HCC.

MHC-I and PD-L1 Expression is Associated with Decreased Tumor Outgrowth and is Radiotherapy-inducible in the Murine Head and Neck Squamous Cell Carcinoma Model MOC1

INTRODUCTION

Combined radiotherapy and immune checkpoint inhibition is a potential treatment option for head and neck squamous cell carcinoma (HNSCC). Immunocompetent mouse models can help to successfully develop radio- immunotherapy combinations and to increase our understanding of the effects of radiotherapy on the tumor microenvironment for future clinical translation. Therefore, the aim of this study was to develop a homogeneous, reproducible HNSCC model originating from the Mouse Oral Cancer 1 (MOC1) HNSCC cell line, and to explore the radiotherapy-induced changes in its tumor microenvironment, using flow cytometry and PD-L1 microSPECT/CT imaging.

MATERIALS AND METHODS

In vivo growing tumors originating from the parental MOC1 line were used to generate single cell derived clones. These clones were screened in vitro for their ability to induce programmed cell death ligand 1 (PD-L1) and major histocompatibility complex class I (MHC-I) following IFNγ exposure. Clones with different IFNγ sensitivity were inoculated in C57BL/6 mice and assessed for tumor outgrowth. The composition of the tumor microenvironment of a stably growing (non)irradiated MOC1-derived clone was assessed by immunohistochemistry, flow cytometry and PD-L1 microSPECT/CT.

RESULTS

Low in vitro inducibility of MHC-I and PD-L1 by IFNγ was associated with increased tumor outgrowth of MOC1 clones in vivo. Flow cytometry analysis of cells derived from a stable in vivo growing MOC1 clone MOC1.3D5low showed expression of MHC-I and PD-L1 on several cell populations within the tumor. Upon irradiation, MHC-I and PD-L1 increased on leukocytes (CD45.2+) and cancer associated fibroblasts (CD45.2-/EpCAM-/CD90.1+). Furthermore, PD-L1 microSPECT/CT showed increased tumor uptake of radiolabeled PD-L1 antibodies with a heterogeneous spatial distribution of the radio signal, which co-localized with PD-L1+ and CD45.2+ areas.

DISCUSSION

PD-L1 and MHC-I inducibility by IFNγ in vitro is associated with tumor outgrowth of MOC1 clones in vivo. In tumors originating from a stably growing MOC1-derived clone, expression of these immune-related markers was induced by irradiation shown by flow cytometry on several cell populations within the tumor microenvironment such as immune cells and cancer associated fibroblasts. PD-L1 microSPECT/CT showed increased tumor uptake following radiotherapy, and autoradiography showed correlation of uptake with areas that are heavily infiltrated by immune cells. Knowledge of radiotherapy-induced effects on the tumor microenvironment in this model can help optimize timing and dosage for radio- immunotherapy combination strategies in future research.

CXCL16 promotes proliferation of head and neck squamous cell carcinoma by regulating GPX1-mediated antioxidant levels

Numerous studies have demonstrated that the high expression of CXC motif chemokine ligand 16 (CXCL16) in cancer correlates with poor prognosis, as well as tumor cell proliferation, migration, and invasion. While CXCL16 can serve as a tumor biomarker, the underlying mechanism in modulating head and neck squamous cell carcinoma (HNSCC) remains unclear. In this study, the aimed was to investigate the CXCL16 expression in HNSCC and to uncover the potential underlying mechanism. Hereby, we determined the high expression of CXCL16 in The Cancer Genome Atlas (TCGA) database, as well as in tissue samples from patients with HNSCC at our central hospital and from HNSCC cell lines. The results showed that CXCL16 knockdown inhibited the proliferation, migration, and invasion of HNSCC cells. Mechanistically, transcriptome sequencing revealed that CXCL16 may affect HNSCC cell growth by regulating the antioxidant pathway of glutathione peroxidase 1 (GPX1). The reactive oxygen species (ROS) levels were elevated in small interfering CXCL16 (si-CXCL16) cells, which may contribute to the inhibition of cell proliferation, migration, and invasion. Moreover, treatment of cells with the GPX1 inhibitor eldecalcitol (ED-71) revealed that HNSCC cell growth was significantly inhibited in the synergistic group of si-CXCL16 and GPX1 inhibitor compared to the si-CXCL16 group. In conclusion, CXCL16 contributed to the development of HNSCC cells by modulating the GPX1-mediated antioxidant pathway. Thus, targeting cellular CXCL16 expression seems to be a promising strategy for treating HNSCC.

Tumor-Localized Interleukin-2 and Interleukin-12 Combine with Radiation Therapy to Safely Potentiate Regression of Advanced Malignant Melanoma in Pet Dogs

PURPOSE

Cytokines IL2 and IL12 exhibit potent anticancer activity but suffer a narrow therapeutic window due to off-tumor immune cell activation. Engineering cytokines with the ability to bind and associate with tumor collagen after intratumoral injection potentiated response without toxicity in mice and was previously safe in pet dogs with sarcoma. Here, we sought to test the efficacy of this approach in dogs with advanced melanoma.

PATIENTS AND METHODS

This study examined 15 client-owned dogs with histologically or cytologically confirmed malignant melanoma that received a single 9-Gy fraction of radiotherapy, followed by six cycles of combined collagen-anchored IL2 and IL12 therapy every 2 weeks. Cytokine dosing followed a 3 + 3 dose escalation design, with the initial cytokine dose chosen from prior evaluation in canine sarcomas. No exclusion criteria for tumor stage or metastatic burden, age, weight, or neuter status were applied for this trial.

RESULTS

Median survival regardless of the tumor stage or dose level was 256 days, and 10/13 (76.9%) dogs that completed treatment had CT-measured tumor regression at the treated lesion. In dogs with metastatic disease, 8/13 (61.5%) had partial responses across their combined lesions, which is evidence of locoregional response. Profiling by NanoString of treatment-resistant dogs revealed that B2m loss was predictive of poor response to this therapy.

CONCLUSIONS

Collectively, these results confirm the ability of locally administered tumor-anchored cytokines to potentiate responses at regional disease sites when combined with radiation. This evidence supports the clinical translation of this approach and highlights the utility of comparative investigation in canine cancers.

The impact of elective cervical lymph node treatment on the tumour immune response in head and neck squamous cell carcinoma: time for a change in treatment strategy?

The elective ablation of cervical lymph nodes, via surgery or irradiation, is a mainstay in the treatment of head and neck squamous cell carcinoma (HNSCC). In this setting, the decision to treat the clinically node negative neck is based upon risk analysis of various factors, primarily derived from tumour features. However, the impact of ablation of tumour-draining lymph nodes upon the tumour-immune response and immunocompetence is largely unknown. In this review we highlight recent evidence of the communication between tumour and tumour-draining lymph nodes and the fundamental importance of this axis. We will provide a perspective of how recent cancer biology discoveries may juxtapose with current treatment pathways, with potential translational line of site for future research. In particular, neo-adjuvant therapy or biomarkers from tumour-draining lymph nodes may present opportunities to preserve lymphatics and harness improved immunocompetence in HNSCC patients.

Immunotherapeutic allogeneic dendritic cell and autologous tumor cell fusion vaccine alone or combined with radiotherapy in canine oral malignant melanoma is safe and potentially effective

Introduction

Immunotherapy represents a promising breakthrough in cancer management and is being explored in canine melanomas. Dendritic cells (DCs) play a crucial role in priming T-cell-mediated immune reactions through the antigen-presenting function. Combining immunotherapy and radiation therapy may generate more substantial anti-cancer efficacy through immunomodulation.

Objectives

Our research reported a preliminary result of the safety and outcome of a kind of immunotherapy, the allogeneic dendritic cell and autologous tumor cell fusion vaccine, alone or in combination with hypofractionated radiation therapy, in canine oral malignant melanoma.

Methods

Two groups of dogs with histopathological diagnoses of oral malignant melanoma were recruited. In group 1 (DCRT), dogs received a combination of DC fusion vaccine and radiotherapy. In group 2 (DC), dogs received DC fusion vaccine alone. DC vaccination was given once every 2 weeks for four doses. Radiotherapy was performed weekly for five fractions. Dogs that received carboplatin were retrospectively collected as a control group (group 3).

Results

Five dogs were included in group 1 (two stage II, three stage III), 11 in group 2 (three stage I/II, eight stage III/IV), and eight (two stage I/II, six stage III/IV) in the control group. Both DC and DCRT were well-tolerated, with only mild adverse events reported, including mucositis, gastrointestinal discomfort, and injection site reactions. The median progression-free intervals in groups 1, 2, and 3 were 214 (95% CI, NA, due to insufficient data), 100 (95% CI, 27-237), and 42 days (95% CI, NA-170), respectively, which were not significantly different. The 1-year survival rates were 20, 54.5, and 12.5% in groups 1, 2, and 3. Dogs in the DCRT group exhibited significantly higher TGF-β signals than the DC group throughout the treatment course, indicating a possible higher degree of immunosuppression.

Conclusion

The manuscript demonstrated the safety of dendritic cell/tumor cell fusion vaccine immunotherapy, alone or in combination with radiotherapy. The results support further expansion of this immunotherapy, modification of combination treatment and protocols, and investigation of combining DC vaccine with other treatment modalities.

Clinical trial registration

Preclinical Trials, PCTE0000475.

TGF-β neutralization attenuates tumor residency of activated T cells to enhance systemic immunity in mice

A tissue resident-like phenotype in tumor infiltrating T cells can limit systemic anti-tumor immunity. Enhanced systemic anti-tumor immunity is observed in head and neck cancer patients after neoadjuvant PD-L1 immune checkpoint blockade (ICB) and transforming growth factor β (TGF-β) neutralization. Using T cell receptor (TCR) sequencing and functional immunity assays in a syngeneic model of oral cancer, we dissect the relative contribution of these treatments to enhanced systemic immunity. The addition of TGF-β neutralization to ICB resulted in the egress of expanded and exhausted CD8+ tumor infiltrating lymphocytes (TILs) into circulation and greater systemic anti-tumor immunity. This enhanced egress associated with reduced expression of Itgae (CD103) and its upstream regulator Znf683. Circulating CD8+ T cells expressed higher Cxcr3 after treatment, an observation also made in samples from patients treated with dual TGF-β neutralization and ICB. These findings provide the scientific rationale for the use of PD-L1 ICB and TGF-β neutralization in newly diagnosed patients with carcinomas prior to definitive treatment of locoregional disease.

Integrating electromagnetic cancer stress with immunotherapy: a therapeutic paradigm

An array of published cell-based and small animal studies have demonstrated a variety of exposures of cancer cells or experimental carcinomas to electromagnetic (EM) wave platforms that are non-ionizing and non-thermal. Overall effects appear to be inhibitory, inducing cancer cell stress or death as well as inhibition in tumor growth in experimental models. A variety of physical input variables, including discrete frequencies, amplitudes, and exposure times, have been tested, but drawing methodologic rationale and mechanistic conclusions across studies is challenging. Nevertheless, outputs such as tumor cytotoxicity, apoptosis, tumor membrane electroporation and leak, and reactive oxygen species generation are intriguing. Early EM platforms in humans employ pulsed electric fields applied either externally or using interventional tumor contact to induce tumor cell electroporation with stromal, vascular, and immunologic sparing. It is also possible that direct or external exposures to non-thermal EM waves or pulsed magnetic fields may generate electromotive forces to engage with unique tumor cell properties, including tumor glycocalyx to induce carcinoma membrane disruption and stress, providing novel avenues to augment tumor antigen release, cross-presentation by tumor-resident immune cells, and anti-tumor immunity. Integration with existing checkpoint inhibitor strategies to boost immunotherapeutic effects in carcinomas may also emerge as a broadly effective strategy, but little has been considered or tested in this area. Unlike the use of chemo/radiation and/or targeted therapies in cancer, EM platforms may allow for the survival of tumor-associated immunologic cells, including naïve and sensitized anti-tumor T cells. Moreover, EM-induced cancer cell stress and apoptosis may potentiate endogenous tumor antigen-specific anti-tumor immunity. Clinical studies examining a few of these combined EM-platform approaches are in their infancy, and a greater thrust in research (including basic, clinical, and translational work) in understanding how EM platforms may integrate with immunotherapy will be critical in driving advances in cancer outcomes under this promising combination.

Interrogating the roles of lymph node metastasis in systemic immune surveillance

Lymph nodes (LNs) are principal orchestrators of the adaptive immune response, yet in the context of malignancy, they are typically the first sites of metastasis. When tumors spread to LNs, they alter the immune repertoire, ultimately reconditioning it in a manner that suppresses anti-tumor immunity and promotes further metastatic dissemination. Conversely, activation of anti-tumor immunity within LNs is essential for immunotherapy, suggesting clinical approaches to radiotherapy in LNs and lymphadenectomy may need to be reconsidered in the context of immune checkpoint blockade (ICB). Herein, we discuss our understanding of the immune remodeling that coincides with LN metastasis as well as recent clinical studies exploring neoadjuvant immunotherapy and the roles of LNs in treatment of solid organ malignancies.

Effects of clinically relevant radionuclides on the activation of a type I interferon response by radiopharmaceuticals in syngeneic murine tumor models

Radiopharmaceutical therapies (RPT) activate a type I interferon (IFN1) response in tumor cells. We hypothesized that the timing and amplitude of this response varies by isotope. We compared equal doses delivered by 90 Y, 177 Lu, and 225 Ac in vitro as unbound radionuclides and in vivo when chelated to NM600, a tumor-selective alkylphosphocholine. Response in murine MOC2 head and neck carcinoma and B78 melanoma was evaluated by qPCR and flow cytometry. Therapeutic response to 225 Ac-NM600+anti-CTLA4+anti-PD-L1 immune checkpoint inhibition (ICI) was evaluated in wild-type and stimulator of interferon genes knockout (STING KO) B78. The timing and magnitude of IFN1 response correlated with radionuclide half-life and linear energy transfer. CD8 + /Treg ratios increased in tumors 7 days after 90 Y- and 177 Lu-NM600 and day 21 after 225 Ac-NM600. 225 Ac-NM600+ICI improved survival in mice with WT but not with STING KO tumors, relative to monotherapies. Immunomodulatory effects of RPT vary with radioisotope and promote STING-dependent enhanced response to ICIs in murine models.

Teaser

This study describes the time course and nature of tumor immunomodulation by radiopharmaceuticals with differing physical properties.

Radiotherapy and immunology

The majority of cancer patients receive radiotherapy during the course of treatment, delivered with curative intent for local tumor control or as part of a multimodality regimen aimed at eliminating distant metastasis. A major focus of research has been DNA damage; however, in the past two decades, emphasis has shifted to the important role the immune system plays in radiotherapy-induced anti-tumor effects. Radiotherapy reprograms the tumor microenvironment, triggering DNA and RNA sensing cascades that activate innate immunity and ultimately enhance adaptive immunity. In opposition, radiotherapy also induces suppression of anti-tumor immunity, including recruitment of regulatory T cells, myeloid-derived suppressor cells, and suppressive macrophages. The balance of pro- and anti-tumor immunity is regulated in part by radiotherapy-induced chemokines and cytokines. Microbiota can also influence radiotherapy outcomes and is under clinical investigation. Blockade of the PD-1/PD-L1 axis and CTLA-4 has been extensively investigated in combination with radiotherapy; we include a review of clinical trials involving inhibition of these immune checkpoints and radiotherapy.

Implementing circulating tumor DNA as a prognostic biomarker in resectable non-small cell lung cancer

Systemic treatment of resectable non-small cell lung cancer (NSCLC) is evolving with emerging neoadjuvant, perioperative, and adjuvant immunotherapy approaches. Circulating tumor DNA (ctDNA) detection at clinical diagnosis, during neoadjuvant therapy, or after resection may discern high-risk patients who might benefit from therapy escalation or switch. This Review summarizes translational implications of data supporting ctDNA-based risk determination in NSCLC and outstanding questions regarding ctDNA validity/utility as a prognostic biomarker. We discuss emerging ctDNA capabilities to refine clinical tumor-node-metastasis (TNM) staging in lung adenocarcinoma, ctDNA dynamics during neoadjuvant therapy for identifying patients deriving suboptimal benefit, and postoperative molecular residual disease (MRD) detection to escalate systemic therapy. Considering differential relapse characteristics in landmark MRD-negative/MRD-positive patients, we propose how ctDNA might integrate with pathological response data for optimal postoperative risk stratification.

Delayed tumor-draining lymph node irradiation preserves the efficacy of combined radiotherapy and immune checkpoint blockade in models of metastatic disease

Cancer resistance to immune checkpoint inhibitors motivated investigations into leveraging the immunostimulatory properties of radiotherapy to overcome immune evasion and to improve treatment response. However, clinical benefits of radiotherapy-immunotherapy combinations have been modest. Routine concomitant tumor-draining lymph node irradiation (DLN IR) might be the culprit. As crucial sites for generating anti-tumor immunity, DLNs are indispensable for the in situ vaccination effect of radiotherapy. Simultaneously, DLN sparing is often not feasible due to metastatic spread. Using murine models of metastatic disease in female mice, here we demonstrate that delayed (adjuvant), but not neoadjuvant, DLN IR overcomes the detrimental effect of concomitant DLN IR on the efficacy of radio-immunotherapy. Moreover, we identify IR-induced disruption of the CCR7-CCL19/CCL21 homing axis as a key mechanism for the detrimental effect of DLN IR. Our study proposes delayed DLN IR as a strategy to maximize the efficacy of radio-immunotherapy across different tumor types and disease stages.

Immune checkpoint inhibitor use in head and neck squamous cell carcinoma: the current landscape and future perspectives

Immune checkpoint inhibitors are licensed for use in patients with unresectable, recurrent or metastatic head and neck squamous cell carcinoma. Multiple published and ongoing trials are assessing efficacy in the curative management of patients in the concomitant, neoadjuvant and/or adjuvant settings, as well as part of multimodality treatment in patients with metastatic disease. This review evaluates the evidence for use of immune checkpoint inhibitors in all stages of head and neck squamous cell carcinoma and considers future approaches.

Let it be: Preserving tumor-draining lymph nodes in the era of immuno-oncology

Solid cancers often progress via metastasis to lymph nodes. Consequently, lymphadenectomy is central to stage cancers and eradicates disease spread. However, mounting evidence suggests that cancer immunotherapies drive antitumor immune responses within lymph nodes. This implies that immunotherapy, delivered with standard oncologic therapies, may require specific treatment sequencing to initiate immunosurveillance and affect primary tumor responses. As supported by recent preclinical and clinical studies, lymphatic-preserving strategies may offer the best promise for driving the next generation of breakthrough immunotherapy approaches.

Targeting lymph nodes for enhanced cancer vaccination: From nanotechnology to tissue engineering

Lymph nodes (LNs) occupy a critical position in initiating and augmenting immune responses, both spatially and functionally. In cancer immunotherapy, tumor-specific vaccines are blooming as a powerful tool to suppress the growth of existing tumors, as well as provide preventative efficacy against tumorigenesis. Delivering these vaccines more efficiently to LNs, where antigen-presenting cells (APCs) and T cells abundantly reside, is under extensive exploration. Formulating vaccines into nanomedicines, optimizing their physiochemical properties, and surface modification to specifically bind molecules expressed on LNs or APCs, are common routes and have brought encouraging outcomes. Alternatively, porous scaffolds can be engineered to attract APCs and provide an environment for them to mature, proliferate and migrate to LNs. A relatively new research direction is inducing the formation of LN-like organoids, which have shown positive relevance to tumor prognosis. Cutting-edge advances in these directions and discussions from a future perspective are given here, from which the up-to-date pattern of cancer vaccination will be drawn to hopefully provide basic guidance to future studies.

Regulatory T-cells activated in metastatic draining lymph nodes possibly suppress cancer immunity in cancer tissues of head and neck squamous cell cancer

Regulatory T cells (Tregs) play an important role in creating an immunosuppressive microenvironment in cancer tissues. However, the mechanisms by which Tregs are activated and suppress cancer immunity remain unclear. To elucidate these mechanisms, we performed a T cell receptor (TCR) repertoire analysis of Tregs and conventional T cells in peripheral blood, draining lymph nodes (DLNs), and cancer tissues of patients with head and neck squamous cell cancer (HNSCC). We found that the TCR repertoire was skewed in cancer tissue and metastatic DLNs (M-DLNs) compared with non-metastatic DLNs, and TCR repertoire similarities in Tregs and CD8+ T cells between M-DLNs and cancer tissue were high compared with those at other sites. These results suggest that Tregs and CD8+ T cells are activated in M-DLNs and cancer tissues by cancer antigens, such as neoantigens, and shared antigens and Tregs suppress CD8+ T cell function in a cancer antigen-specific manner in M-DLNs and cancer tissue. Moreover, M-DLNs might be a source of Tregs and CD8+ T cells recruited into the cancer tissue. Therefore, targeting Tregs in M-DLNs in an antigen-specific manner is expected to be a novel immunotherapeutic strategy for HNSCCs.