Oral cancer remains a major health issue worldwide. Oral Potentially Malignant Disorders (OPMDs) constitute a wide range of lesions and conditions found in the oral cavity with a known risk of developing into oral squamous cell carcinoma. Common OPMDs include leukoplakia, erythroplakia, oral submucous fibrosis, oral lichen planus, and proliferative verrucous leukoplakia. Timely, well-targeted biopsy, coupled with risk-adapted follow-up and multidisciplinary care is essential to reduce malignant progression and achieve optimal patient outcomes. To address the absence of a unified weighting scheme for clinical and pathological predictors of malignant transformation in OPMDs, we conducted a targeted expert survey within the COST action INTERCEPTOR Working Group 2 (clinician-researchers with formal expertise in OPMDs). History of previous head and neck cancer, OPMD type, multifocality of the lesion clinical appearance and lifestyle habits received the highest weights in the survey on clinical prognostic factors. Future research priorities include development and validation of predictive models integrating clinical, histological, and molecular variables.

Oral epithelial dysplasia (OED) is the principal histopathological marker for malignant risk stratification in oral potentially malignant disorders (OPMDs). Current World Health Organisation (WHO) three-tier and other binary grading systems are limited by modest inter-observer reproducibility and suboptimal prognostic discrimination, particularly for architecture-predominant lesions where cytological atypia is inconspicuous. The most clinically consequential failure of current practice is not mis-grading but non-recognition of dysplasia altogether, with direct implications for patient surveillance and management. This position paper, arising from Working Group 2 of COST Action CA21140 INTERCEPTOR, synthesises evidence from inter-observer reproducibility studies, feature-based prognostic models, under-recognition studies, outcome data and computational pathology analyses to propose and contextualise a pattern-anchored, grade-retaining diagnostic framework for OED. Five recognisable histological patterns are proposed: conventional/basaloid, keratinising/differentiated, verrucous, papillomatous, and HPV-associated, functioning as diagnostic anchors that capture the full morphological spectrum of OED, including architecture-predominant phenotypes that are disproportionately under-recognised in routine practice. Feature-based prognostic models demonstrate that architectural traits characterising these patterns (bulbous rete ridges, AUROC 0.74; cohesion loss, AUROC 0.73) predict malignant transformation more effectively than grade alone. Independent computational pathology analyses identify corresponding immune microenvironment and architectural signals as the strongest prognostic variables, providing convergent support. A two-step approach i.e. first identifying the dominant morphological pattern and then assigning grade within that pattern using existing WHO or binary criteria, offers a pragmatic, grade-retaining refinement compatible with current diagnostic frameworks and clinical pathways. The proposal is hypothesis-driven and requires prospective multicentre validation before wider adoption.

Abstract DNA methylation profiling is an integral diagnostic tool in the classification of central nervous system (CNS) tumors. While the Heidelberg CNS Tumor Methylation Classifier is widely used to support CNS tumor diagnostics, new classifiers such as CrossNN are emerging. However, their clinical performance and added value within routine diagnostic workflows remain insufficiently explored. In this study, we evaluated the diagnostic performance of the CrossNN classifier in a real‐world CNS tumor cohort and compared it with the established Heidelberg classifier to assess its potential as both a non‐inferior alternative and a complementary tool to improve diagnostic accuracy. A retrospective cohort of CNS tumors profiled using Illumina Human Methylation 930k EPIC v2 BeadChip arrays was analyzed. Classifier outputs were compared with integrated WHO CNS5 (2021) diagnoses. In addition, CrossNN and Heidelberg outputs were harmonized to WHO CNS5 (2021) tumor type levels and evaluated both individually and within sequential and parallel diagnostic workflows. The proposed workflows were subsequently assessed in an independent prospective validation cohort. Among 205 samples, CrossNN correctly classified 88.8% of cases and demonstrated 86.8% concordance with the Heidelberg classifier. CrossNN demonstrated non‐inferior classification performance compared with the Heidelberg classifier. Combining both classifiers increased the number of clinically informative and correct classifications by nearly 10%. This finding was confirmed in an independent validation cohort of 41 samples. In conclusion, these results demonstrate the complementary strength of the CrossNN and Heidelberg classifiers as a dual‐classifier strategy to improve diagnostic confidence and accuracy in routine CNS tumor diagnostics.

Biliary tract cancers (BTCs) are aggressive malignancies associated with a poor prognosis. Although molecular profiling is recommended to guide therapeutic decision-making, real-practice data on the prevalence and prognostic significance of genomic alterations in European BTC cohorts remain limited. This retrospective cohort study characterized the molecular landscape of BTCs in a Belgian real-practice setting and evaluated its prognostic relevance. Patients with BTC who underwent informative molecular testing as part of routine diagnostics at Antwerp University Hospital between 2016 and 2024 were included. Demographic, clinical, and molecular data were extracted from electronic health records. Survival outcomes were analyzed using Kaplan-Meier methods and Cox proportional hazards regression. Among 224 included patients, genomic alterations were identified in 59.4% of tumors, with clear subtype-specific patterns. IDH1 mutations (17.3%) and FGFR2 fusions (13.9%) were exclusively observed in intrahepatic cholangiocarcinoma, KRAS mutations were most prevalent in extrahepatic cholangiocarcinoma (42.9%), and ERBB2 amplification was enriched in gallbladder cancer (16.7%). Co-occurring alterations were present in 7.8% of cases. KRAS mutation was the most frequent alteration overall (20.4%) and remained significantly associated with worse overall survival in multivariate analysis adjusted for tumor subtype and tumor stage (HR = 1.54, 95% CI: 1.03-2.31, p = 0.04). Although 32.6% of tumors harbored a potentially actionable alteration, only 31.6% of eligible patients received matched targeted therapy. These findings underscore the clinical value of routine molecular profiling in BTC and highlight its importance for identifying therapeutic opportunities in clinical practice.

Chimeric antigen receptor (CAR) therapies have shown great success in hematological malignancies but remain largely ineffective against solid tumors such as pancreatic ductal adenocarcinoma (PDAC). A key obstacle among various aspects, is the dense stromal barrier formed by cancer-associated fibroblasts (CAFs), providing a rationale for simultaneously targeting stroma and tumor cells. Using immunohistochemistry of primary PDAC tumors and liver metastases, we confirmed high mesothelin (MSLN) expression on tumor cells, and CD70 expression on tumor cells and predominantly CAFs. Based on these results and the favorable safety profile of CAR natural killer (NK) cells over CAR T cells, we generated MSLN- and CD70-targeting IL-15-armored CAR NK cells. Both constructs mediated cytotoxicity against different pancreatic cancer and CAF cell lines with varying antigen expression in vitro, demonstrating that both, the CAR-molecule and IL-15 were required to increase functionality against more treatment-resistant cell lines. Interestingly, pooled MSLN- and CD70-CAR NK cells did not significantly improve cytolysis compared to monotherapies in an advanced 3D in vitro model or in vivo. Together these findings highlight the limitations of dual-targeting approaches and underscore the need for advanced engineering strategies to improve CAR NK cells beyond antigen targeting and cytokine support in the PDAC microenvironment.

The management of locally-advanced, resectable head and neck squamous cell carcinoma (HNSCC) is undergoing a major shift driven by the integration of neoadjuvant immunotherapy (nIO). The rationale for nIO lies in its administration within an immunologically active, treatment-naïve microenvironment that enhances immune priming and anti-tumor response. Despite encouraging clinical data, including the pivotal KEYNOTE-689 trial and multiple phase II studies, methodological heterogeneity in trial design, endpoint definitions, and response criteria currently hampers data comparability and the establishment of new standards of care. This expert narrative review proposes a structured framework for standardizing clinical, pathologic, imaging, and translational endpoints in HNSCC nIO trials, highlighting harmonized definitions of pathologic response, practical reporting templates, and methods to evaluate immune priming. Standardization of response evaluation, biomarker integration, and trial methodology is essential to accelerate the translation of neoadjuvant immunotherapy into routine clinical practice for HNSCC.

In oral squamous cell carcinoma (OSCC) surgery, inadequate tumor margins are reported in up to 85% of cases, adversely affecting outcomes. In this prospective, single-center study (n = 31; NCT04191460), we evaluated the safety and imaging feasibility of cRGD-ZW800-1, a near-infrared fluorescent integrin-targeted tracer. The secondary objective was to determine whether intraoperative fluorescence imaging could identify inadequate resection margins and inform surgical decision-making. Patients received 0.01, 0.025, or 0.05 mg/kg cRGD-ZW800-1, and tracer uptake was quantified using in vivo multi-diameter single-fiber reflectance and single-fiber fluorescence spectroscopy to optimize dosing and timing. All doses were well tolerated, achieving tumor-to-background ratios exceeding 4.5, with optimal performance at 0.025 mg/kg. Fluorescence imaging detected all 23 inadequate margins, including nine undetected by conventional assessment (sensitivity 100% versus 70%), altered surgical plans in five cases, and avoided adjuvant radiotherapy in three cases. These findings demonstrate that cRGD-ZW800-1 is safe, tumor-specific, and facilitates intraoperative margin assessment in OSCC. Incomplete tumor removal during oral cancer surgery remains a major clinical challenge. Here, the authors show, in a feasibility trial, that fluorescence imaging using the integrin-targeted tracer cRGD-ZW800 is safe, achieved a patient-level sensitivity of 100%, enabled additional fluorescence-guided resections and prevented postoperative radiotherapy in some patients with oral squamous cell carcinoma.

Background Despite its viral etiology and immunogenic features, cervical cancer shows limited and often short-lived benefit from programmed cell death protein 1 blockade, currently the only approved immunotherapy for this disease. This limitation highlights the need for a deeper understanding of its immune microenvironment to uncover alternative or complementary immunotherapeutic targets that may improve outcomes. Methods We integrated spatial proteomic and bulk transcriptomic profiling of the cervical cancer immune landscape. Immune subset markers (CD8, CD4, CD68, FoxP3, NKp46) and clinically actionable immune checkpoint molecules (HLA-E, CD47, CD73, CD276, CD155, Gal-9, PD-L1, CD70, LAG-3) were assessed by immunohistochemistry in 65 resected tumors, spatially resolved across tumor stroma and tumor epithelium niches. Expression patterns and correlations with clinicopathological variables, immunotypes, and survival were systematically analyzed. Key findings were cross-validated in The Cancer Genome Atlas cohort, and tumor-killing assays were conducted to evaluate the therapeutic potential of identified checkpoint axes. Results Immune infiltration was predominantly localized to the tumor stroma, with CD8+ and CD4+ T cells as dominant subsets. Within the tumor epithelium, CD8+ T cells and CD68+ macrophages were most abundant. Among checkpoints, HLA-E and CD47 showed the highest and most widespread expression, whereas CD276 and CD155 were enriched in the tumor epithelium, and CD73 and CD70 in the tumor stroma. Squamous cell carcinoma showed a stronger immunologic profile than adenocarcinoma. Immunotype stratification revealed distinct expression profiles and prognostic patterns. Elevated niche-defined expression of CD8, CD4, CD4-FoxP3, and NKp46 associated with improved survival. CD155 emerged as the only checkpoint consistently linked with poor survival across niches and cohorts, and associated with chemotherapy resistance. Notably, CD155 was the most promising functional target and was highly and selectively enriched in the tumor epithelium across all immunotypes, including immune-desert tumors where other immune markers were scarce. Conclusion This study reveals a complex, niche-specific and immunotype-specific immunoregulatory architecture in cervical cancer that extends well beyond programmed death-ligand 1. CD155 stands out as a compelling and underused therapeutic target, supporting a paradigm shift in targeting the T cell immunoreceptor with Ig and ITIM domains (TIGIT) axis. Its functional impact and selective enrichment in the tumor epithelium positions CD155 as a promising therapeutic target for both checkpoint inhibition and epithelial-directed approaches in cervical cancer.

Purpose In pancreatic ductal adenocarcinoma (PDAC), immune checkpoint inhibitors have shown limited efficacy, and the role of the TIGIT axis remains underexplored. This study aimed to characterize TIGIT axis components on protein level and their relationship to PD-1/PD-L1 expression in matched blood and tumor samples from PDAC patients to identify immunosuppressive mechanisms and fuel future strategies for immune checkpoint co-targeting in PDAC patients. Experimental design Fresh tumor and peripheral blood samples were collected from PDAC patients undergoing surgical resection. Flow cytometry was performed on tumor-infiltrating lymphocytes and PBMCs to assess expression of TIGIT, DNAM-1, TACTILE, and PD-1. Ligands CD111, CD112, CD113, and CD155 were analyzed using immunohistochemistry. Additional RNA expression analysis (TCGA/GTEx) was used to evaluate ligand distribution and gene expression profiles. Results TIGIT was highly upregulated on intratumoral CD8⁺ T cells and regulatory T cells, frequently co-expressed with PD-1. DNAM-1 expression was significantly reduced in tumors. However, contrasting pattern emerges with Tregs, which uniquely upregulate DNAM-1 in the PDAC TME. In addition, CD112 and CD155 were broadly expressed, including novel stromal CD112 localization. NK cells were nearly absent intratumorally, correlating with DNAM-1 downregulation. Conclusions Our findings identify TIGIT as a promising immunotherapeutic target in PDAC and suggest that dual checkpoint blockade (TIGIT/PD-1), alongside restoration of DNAM-1 signaling, may overcome immune suppression. These results provide mechanistic rationale to inform future clinical trials in PDAC. Supplementary Information The online version contains supplementary material available at 10.1007/s00262-026-04343-w.