BACKGROUND:Epstein-Barr virus (EBV)-positive small cell neuroendocrine carcinoma of the nasopharynx (SCNEC-nasopharynx) is exceptionally rare and aggressive, with poorly characterized molecular features. METHODS:Clinicopathological, immunohistochemical (synaptophysin, INSM1, chromogranin A, CK-pan, EGFR, NUT, INI1), and molecular profiles of 15 EBV-positive SCNEC-nasopharynx cases (2012-2025) were analysed. EBV status was confirmed by EBER-ISH. Exploratory next-generation sequencing compared nine SCNEC with five EBV-positive nasopharyngeal non-keratinizing carcinomas (NKUC). RESULTS:Patients (median age 51; male:female = 2:1) presented with advanced-stage disease and cervical lymphadenopathy. Histology showed solid nests of small cells with high-grade features. All tumours were diffusely positive for synaptophysin and EBER, showed perinuclear dot-like CK-pan staining, and were negative for squamous markers and EGFR. NUT was negative and INI1 retained. Comparative genomics revealed greater mutational burden and unique alterations enriched in cell cycle/DNA damage pathways in SCNEC versus NKUC. After multimodal therapy, median overall survival was 33 months. CONCLUSION:This largest integrated study defines the distinct clinicopathological and molecular profile of EBV-positive SCNEC-nasopharynx. The identified diagnostic immunophenotype and potential oncogenic pathways provide a foundation for precise diagnosis and future targeted therapy development.

This study aimed to assess the potential diagnostic utility of immune receptor translocation-associated protein 1 (IRTA1) and myeloid nuclear differentiation antigen (MNDA) expression in marginal zone lymphoma (MZL). We evaluated whole-tissue sections from 686 specimens; specifically, reactive lymphoid hyperplasia (n=60), MZL (n=284), follicular lymphoma (n=156), mantle cell lymphoma (n=64), chronic lymphocytic leukaemia/small lymphocytic lymphoma (n=51), lymphoplasmacytic lymphoma (n=17), and diffuse large B-cell lymphoma (DLBCL; n=54). Immunohistochemical staining for IRTA1, MNDA, and other markers (CD10, BCL-6, CD5, CD23, cyclin D1, SOX-11, and LEF-1) was performed using an automated system. IRTA1 was expressed in 62.3% (177/284) of MZL vs 8.7% (25/288) of other small B-cell lymphoma and 14.81% (8/54) of DLBCL specimens (p<0.001 and p<0.001, respectively). MNDA was expressed in 60.9% (173/284) of MZL vs 24.7% (71/288) of other small B-cell lymphoma and 25.93% (14/54) DLBCL specimens (p<0.001 and p<0.001, respectively). Expression of IRTA1 had a higher specificity than MNDA for MZL. Expression of either IRTA1+ or MNDA+ was detected in 78.9% (224/284) of MZL specimens, whereas coexpression was less common (44.4%, 126/284). Within MZL subtypes, IRTA1 and MNDA were expressed at lower frequencies in nodal MZL (55.7% and 55.7%, respectively) than in mucosa-associated lymphoid tissue lymphoma (64.1% and 62.7%, respectively). Expression of IRTA1 alone, or either IRTA1+ or MNDA+, was less frequent among MZL with plasma cell differentiation than among MZL with classical cell morphology (p=0.063 and 0.071, respectively), albeit not significantly. IRTA1 and MNDA are sensitive and specific markers for the differential diagnosis of MZL, and they may be helpful in distinguishing MZL from histologic mimics.

[This corrects the article DOI: 10.3389/fonc.2026.1741406.].

This study examined the prognostic significance of tumor budding (TB) and poorly differentiated clusters (PDCs) in 232 patients with primary cutaneous melanoma (CM). Through retrospective analysis and Cox regression models, TB-3 and ulceration were identified as independent prognostic factors for overall survival, while AJCC stage IV and PDCs were associated with progression-free survival. Additionally, factors such as ulceration, vascular invasion, lymph node metastasis, TB-3, PDCs, non-brisk tumor-infiltrating lymphocytes (TILs), and Breslow thickness were significantly linked to prognosis. A nomogram developed from these findings demonstrated strong predictive accuracy (AUC = 0.839). The results suggest that incorporating TB and PDCs into the current CM staging systems could enhance risk stratification and clinical decision-making.

This study aimed to develop and validate a comprehensive model that uses clinicopathological and computed tomography (CT) imaging features to non-invasively predict epidermal growth factor receptor (EGFR) mutation subtypes in patients with lung adenocarcinoma (LUAD), offering a valuable reference for precise diagnosis and treatment. A total of 318 surgically resected LUAD cases were analyzed. EGFR gene mutations were identified using multiplex fluorescence polymerase chain reaction. Multivariate logistic regression analysis identified independent predictors for the L858R mutation (sex, follicle-predominant type, burr sign, and ground-glass nodule [GGN]); the 19-del mutation (sex, acinar dominant type, burr sign, and GGN); and rare mutations (solid dominant type, spread through air spaces [STAS], and burr sign). Based on these predictors, subtype-specific prediction models were constructed and visualized as nomograms. Predictive performance was assessed through internal validation, receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis. The area under the curve (AUC) values for the L858R, 19-del, and rare mutation prediction models were 0.745, 0.863, and 0.792, respectively. Internal validation demonstrated favorable discrimination, calibration, and clinical utility. The EGFR mutation prediction model for LUAD developed in this study exhibited robust performance and may serve as a valuable tool for precise diagnosis and treatment planning in LUAD.

Neurotrophic tyrosine receptor kinase (NTRK) fusions are crucial in tumorigenesis and in guiding targeted therapy with TRK inhibitors. However, their rarity, fusion heterogeneity, and limitations of conventional pan-TRK immunohistochemistry (IHC) impede accurate clinical detection. This multicenter retrospective study analyzed 374 next-generation sequencing/fluorescence in situ hybridization-validated samples (195 NTRK positive and 179 NTRK negative) collected from 12 Chinese centers to investigate fusion heterogeneity and refine the interpretation of pan-TRK IHC. We developed an amplification protocol by combining the traditional pan-TRK IHC (EPR17341) with the OptiView Amplification Kit and established new interpretation criteria. A total of 40 solid tumor types were included, and 23 unique fusion partners were identified. Papillary thyroid cancer was the most common NTRK-positive tumor (49.74%) and harbored all 3 NTRK subtypes. Among NTRK-positive samples, NTRK3 (74.87%) was the most prevalent subtype, followed by NTRK1 (23.59%). ETS variant transcription factor 6 (ETV6) was the most frequent fusion partner identified in 122 of 195 cases. It was uniquely shared across all 3 NTRK subtypes, with its fusion to NTRK1 being reported for the first time. NTRK1 and NTRK3 exhibited marked fusion partner specificity, with no overlap in their associated partners except for ETV6. The optimized pan-TRK IHC protocol significantly improved staining efficiency by enhancing intensity and clarity. Consequently, the newly established criteria (cytoplasmic intensity ≥1 in ≥50% of tumor cells or any nuclear intensity ≥1) exhibited outstanding detection performance, achieving an overall sensitivity of 94.36% and increasing specificity to 79.89% compared with 60.22% under the conventional protocol. Particularly, the detection sensitivity for NTRK3 fusions was significantly enhanced and reached 95.89%. This study contributes to clarifying NTRK fusion distribution in patients and validates a standardized, sensitive pan-TRK IHC strategy for clinical screening.

INTRODUCTION:Deulorlatinib (TGRX-326), a potent third-generation anaplastic lymphoma kinase (ALK) inhibitor, has reported promising activity and a favorable safety profile in ALK-positive NSCLC in a phase 1 trial. Here, we report the primary results of the pivotal phase 2 trial (NCT05955391) evaluating deulorlatinib in patients with ALK-positive NSCLC in whom second-generation ALK inhibitors had failed. METHODS:This single-arm, phase 2 trial was conducted at 36 centers in China. Eligible patients received deulorlatinib 60 mg once daily. The primary end point was objective response rate (ORR) assessed by an independent review committee (IRC). Key secondary end points included disease control rate, progression-free survival (PFS), duration of response, overall survival, intracranial efficacy, and safety. Exploratory biomarker analyses were performed using cell-free DNA. RESULTS:The efficacy and safety analysis sets comprised 158 and 163 patients, respectively. The primary end point was met with an IRC-assessed ORR of 43.7% (95% confidence interval [CI], 35.8-51.8). The IRC-assessed median PFS was 11.1 months (95% CI, 8.3-13.7). Among patients with measurable central nervous system (CNS) metastases (n = 43), the intracranial ORR was 55.8% (95% CI, 39.9-70.9). In patients harboring the G1202R mutation (n = 8), robust activity was observed (ORR: 62.5%; disease control rate: 100%; median PFS: 11.0 months). The investigator-assessed results were consistent with the IRC-assessed findings. Treatment-related adverse events occurred in 96.3% of patients (47.2% grade ≥3). Nevertheless, dose modifications were infrequent (interruption, 13.5%; reduction, 11.0%; permanent discontinuation, 0.6%). The incidence of CNS-related treatment-related adverse events was 12.9%, with no patients interrupting or discontinuing treatment owing to CNS toxicity. CONCLUSIONS:Deulorlatinib indicated encouraging antitumor activity in patients with advanced ALK-positive NSCLC after failure of second-generation ALK inhibitors, including those with the G1202R mutation. Given its favorable safety profile, deulorlatinib represents a promising new option for this population.

AIMS:Epstein-Barr virus (EBV)-positive inflammatory follicular dendritic cell sarcoma (EBV+ IFDCS) is a rare, indolent malignant neoplasm. Due to its rarity, a comprehensive assessment of its immunophenotypic spectrum and molecular analysis is still lacking. This study aimed to characterize the immunophenotypic and genetic alterations of EBV+ IFDCS to improve understanding of its cell of origin and molecular pathogenesis and to identify potential therapeutic targets. METHODS AND RESULTS:Immunohistochemical staining for a panel of follicular dendritic cell (FDC) and fibroblastic reticular cell (FRC) lineage markers, along with targeted next-generation sequencing, was performed. Nineteen cases of EBV+ IFDCS were classified into four immunophenotypes: nine FDC, two FRC, three biphasic and five null phenotypes. Morphologically, cases with a null phenotype more frequently exhibited a lymphoma-like growth pattern (4/5, 80%) compared with those with a definite FDC and/or FRC phenotype (1/14, 7.1%, P = 0.006). Moreover, a scattered distribution of neoplastic cells was more commonly observed in null phenotype cases (4/5, 80%) than in FDC and/or FRC phenotype cases (3/14, 21.4%, P = 0.038). Targeted sequencing revealed somatic variants in chromatin modifier-related genes in 60.0% (9/15), homologous recombination repair (HRR)-related genes in 53.3% (8/15) and Hippo pathway-related genes (FAT2 and FAT1) in 26.7% (4/15) of cases. CONCLUSIONS:These findings demonstrate the wide morphological and immunophenotypic spectrum of EBV+ IFDCS. Furthermore, variants in chromatin modifier and HRR-related genes may participate in its pathogenesis, and PARP inhibition may represent a potential therapeutic strategy for patients with unresectable disease.

The role of thymic epithelial cells (TECs) in eliminating self-reactive T cells through the presentation of self-antigens is well-established. However, it remains unclear whether TECs can eliminate tumor-reactive CD8+ T cells by presenting tumor antigens. In this study, we observed that CD73+ Granzyme B+ peripheral activated CD8+ T cells undergo apoptosis in the medullary region of the thymus in DEN-CCL4-induced spontaneous HCC mice, but not in the naïve control group. Mechanistically, HCC cells manipulate the thymus to recruit peripheral activated CD8+ T cells through the CCL19/CCL21-CCR7 axis. Additionally, TECs capture antigens from HCC cells for subsequent antigen presentation instead of de novo expressing tumor antigens. When tumor-associated CD8+ T cells homing to the thymus recognize the same tumor antigen presented by TECs, activation-induced cell death (AICD) is initiated in these T cells. Thymectomy redistributes CD8+ T cells into the tumor focus to suppress HCC growth. Alternatively, both inhibiting CCL19/CCL21 expression of thymic cells using an AMPK activator and blocking CCR7 on CD8+ T cells binding with ligands using Cmp2105 significantly reduces tumor-educated thymus dependent immune evasion. Our findings collectively demonstrate that HCC manipulates the thymus to trigger immune escape; pharmacologically targeting CCL19/CCL21-CCR7 axis to inhibit thymus homing can increase CD8+ T cells in the tumor microenvironment.

The BRAFV600E mutation test for melanoma patients has become the key to precision therapy. In this study, we compared the concordance of immunohistochemistry (IHC), quantitative real-time PCR (qPCR), and next-generation sequencing (NGS) in detecting the BRAFV600E mutation in a Chinese melanoma patient population. In addition, this study evaluated the BRAFV600E mutation heterogeneity between primary and metastatic melanoma sites, as well as within the same lesion, and investigated the association between BRAFV600E mutation status and tumor cell morphology. A total of 880 samples from 555 patients diagnosed with malignant melanoma were collected, and IHC for BRAFV600E was conducted. Of these, 385 were subjected to qPCR and 115 to NGS concurrently. Inter and intratumor heterogeneities of BRAFV600E mutations were compared. Hematoxylin and eosin (H&E) stain was performed, and the cell morphologies were reviewed. The IHC and qPCR results were discordant in 14 cases, yielding a concordance rate of 96.36%. IHC and NGS results showed a concordance rate of 97.39%. The sensitivity and specificity of BRAFV600E detection by IHC were 96.95% and 99.46%, with an overall concordance rate of 98.80%. One of 130 patients (0.77%) showed intertumor heterogeneity, and 3 of 880 samples (0.34%) showed intratumor heterogeneity. VE1 staining patterns significantly differed across cell morphologies (P < .01). Compared with qPCR and NGS, VE1 IHC offers high sensitivity, specificity, and consistency in detecting the BRAFV600E mutation in melanomas. The BRAFV600E mutation in melanoma exhibits low intertumor and intratumor heterogeneities and is significantly associated with tumor cell morphology; tumors with epithelioid cell morphology are most likely to harbor the BRAFV600E mutation.

Surgical decision making for early gastric cancer (EGC) is heavily influenced by its metastasis into the lymph nodes. Currently, the clinicopathological features of EGC cannot be used to accurately distinguish between EGC patients with and without lymph node metastasis. Our retrospective case-matching study included a total of 132 samples from 66 pairs of EGC patients with or without lymph node metastasis and conducted proteomic assays. By comparing the lymph node metastasis group and the nonmetastasis group, we found that two proteins, GABARAPL2 and NAV1, were significantly associated with lymph node metastasis in EGC patients. Our prediction model using protein biomarkers had good prediction accuracy, with an area under the curve (AUC) of 0.87, a sensitivity of 0.78, a specificity of 0.89, and an accuracy of 0.84, which can help distinguish between EGC patients with and without lymph node metastasis and guide the decision-making process for performing tailored surgery.

Current understanding of immune characteristics in gastric cancer remains limited for guiding clinical practice, particularly immunotherapy. This study aims to elucidate the multidimensional landscape of tumor microenvironment in gastric cancer, identify predictive biomarkers potentially associated with favorable immunotherapy response, and propose a precision stratification framework to inform therapeutic strategies. This study introduces a novel immune classification system tumor immune microenvironment (TIME)-inflamed, TIME-desert, and TIME-excluded), and characterize the cellular and molecular characteristics of each subtype. TIME-inflamed tumors exhibit significantly higher infiltration of immune cells in tumor regions, as well as increased expression of inflamed-genes. TIME-desert tumors display minimal immune cell infiltration and feature abnormal microvasculature. TIME-excluded subtype is defined by immune cell accumulation outside the tumor with ineffective intratumoral infiltration, prominent fibroblast activity, and collagen deposition. Application of this immune classification system to stratify gastric cancer within the SPACE cohort successfully demonstrates potential for predicting favorable outcomes of a subset of "cold tumor" patients upon receiving combined immunotherapy and chemotherapy. The findings contribute to advancing the classification of gastric cancer from traditional histopathological subtyping to functional immunological subtyping, providing a valuable scientific foundation for precise patient stratification and the development of individualized immunotherapy strategies in clinical practice.

5-Hydroxymethylcytosine (5hmC) modification represents a significant epigenetic modification within DNA, playing a pivotal role in a range of biological processes associated with various types of cancer. The role of 5hmC in systemic anaplastic large cell lymphoma (ALCL) has not been thoroughly investigated. This study aims to examine the function of 5hmC in the advancement of ALCL. Formalin-fixed, paraffin-embedded (FFPE) tumor tissues (n = 46) were obtained from ALCL patients. GEO dataset was used to analyze the expression 5hmC-relative enzymes. Immunohistochemistry was conducted to assess the level of 5hmC and Ten-eleven translocation 2 (TET2) on FFPE samples. The ALK-positive cell line, Su-DHL-1, and the ALK-negative cell line, DL-40, were utilized as in vitro experimental models. RNA-sequencing and hMeDIP-sequencing assays were performed to explore the potential functions of TET2 in cell cycle regulation. Our study identified a reduction of 5hmC levels in patients with ALCL, which exhibited a positive correlation with TET2 expression. Downregulation TET2 resulted in decreased 5hmC levels and facilitated the progression of the cell cycle in ALCL cell lines. hMeDIP-seq and subsequent functional analyses demonstrated the involvement of thioredoxin interacting protein (TXNIP) in the regulation of ALCL cells. Further mechanistic studies revealed that 5hmC levels influenced TXNIP expression. Our study underscores the pivotal roles of 5hmC and TET2 in the regulation of cell cycle progression in ALCL. Therapeutic strategies aimed at targeting 5hmC modification or TET2 may offer a novel approach for the management of ALCL.

Background:Rearranged during transfection (RET) fusion is a key driver in non-small cell lung cancer (NSCLC). Accurate detection is essential for targeted therapeutic strategies, and its reliability varies with the diagnostic methods employed. This study systematically compares the concordance of various molecular profiling techniques for identifying RET fusions in early-stage NSCLC. Methods:This retrospective study included 40 NSCLC patients with RET fusions (RET+) identified by DNA sequencing (DNA-seq). Comprehensive detection was conducted using fluorescence in situ hybridization (FISH) and RNA sequencing (RNA-seq), incorporating both targeted RNA-seq and whole-transcriptome sequencing (WTS). Clinical and molecular features were evaluated for associations with fusion types. Results:Patients were predominantly female (67.5%) and never-smokers (87.5%), with a median age of 53 years. All patients underwent FISH, while 39 cases underwent RNA-seq, with one excluded due to RNA quality control failure. The most common fusions were KIF5B::RET and CCDC6::RET (89.7%), alongside noncanonical fusion partners such as ERC1 (5.0%) and CCDC186 (2.5%). WTS achieved a 79.5% (31/39) RET+ detection rate. Targeted RNA-seq uncovered an additional five RET+ cases missed by WTS. Concordance rates for fusion detection were 92.3% between DNA-seq and RNA-seq, 84.6% between RNA-seq and FISH, and 82.5% between DNA-seq and FISH. Interestingly, patients exhibiting nonreciprocal RET translocations were significantly younger (P=0.03) and presented a lower Ki67 proliferation index (P=0.03). Conclusions:Our findings underscore the complexity of RET fusion characterization and the necessity for a comprehensive diagnostic approach, which enhances the identification of both canonical and noncanonical alterations. This supports precision oncology initiatives aimed at optimizing treatment outcomes for RET+ NSCLC patients.

The current tumor‒node‒metastasis (TNM) staging system cannot provide sufficient information for prognosis and chemotherapy benefits in patients with colorectal cancer (CRC). The tumor microenvironment plays a critical role in disease progression and therapeutic response. Here, we developed and validated a multimodal tumor microenvironment signature of CRC (MTMSCRC) using 1314 CRC patients to enhance prognosis and chemotherapy benefit predictions. We found that the MTMSCRC is an independent predictor of prognosis. Furthermore, incorporating the MTMSCRC and clinicopathological characteristics into the integrated nomograms significantly outperformed traditional models and the TNM staging system. Shapley values identified the MTMSCRC as the most important predictor. Moreover, chemotherapy had no impact on prognosis in nomogram-predicted low-risk score patients but was associated with improved prognosis in medium and high-risk score patients. In summary, the MTMSCRC is a valuable prognostic predictor in CRC patients and the integrated nomogram may help identify those who could benefit from chemotherapy.

BACKGROUND:The accurate diagnosis of melanoma significantly improves patient survival rates. Distinguishing melanomas from naevi purely by morphology can be challenging when neoplastic cells are confined to the epidermis or lack marked nuclear pleomorphism. OBJECTIVES:To investigate candidate DNA methylation alterations that can distinguish melanoma from naevus; to develop an efficient and convenient methylation-specific quantitative real-time polymerase chain reaction assay (MS-qPCR) for the diagnosis of melanoma; and to validate the diagnostic performance of the MS-qPCR. METHODS:We collected 145 formalin-fixed paraffin embedded tissue (FFPE) samples of malignant melanoma, 143 FFPE samples of benign naevus, 31 plasma samples from patients with melanoma and 37 plasma samples from healthy control skin between March 2018 and July 2024. The FFPE samples were divided into a discovery set, a training set and a validation set. PRAME, CLDN11 and SHOX2 promoter methylation levels were detected in the discovery set by pyrosequencing, to identify melanoma-specific methylation markers. Using these genes, we developed an efficient and convenient MS-qPCR diagnostic model and validated its diagnostic performance in the training set, validation set and plasma samples. RESULTS:Pyrosequencing in the discovery set showed that PRAME and CLDN11 promoter methylation levels were significant diagnostic biomarkers of melanoma; no significant differences in SHOX2 promoter methylation were found between melanoma and naevi. MS-qPCR for the detection of PRAME and CLDN11 methylation levels was established. A diagnostic algorithm based on cycle threshold values was constructed and achieved high accuracy in the training set (sensitivity 94.3%, specificity 85.6%), validation set (sensitivity 84.5%, specificity 88.7%) and plasma samples (sensitivity 51.6%, specificity 83.8%). In terms of melanoma subtypes, the diagnostic algorithm enabled a high degree of discrimination between acral (sensitivity 89.9%, specificity 86.4%) and mucosal melanoma (sensitivity 100%, specificity 83.3%). More importantly, the diagnostic algorithm was able to distinguish early-stage melanoma from normal naevus, with an area under the curve of 0.879 and sensitivity of 77.3%. CONCLUSIONS:The approach to detecting PRAME and CLDN11 methylation levels using MS-qPCR has high sensitivity and specificity in the differential diagnosis between benign and malignant melanocytic tumours. Using this approach in plasma is a promising and easily implementable strategy for early melanoma screening.