Search Results (471)

Background/Objectives: High-grade pulmonary neuroendocrine carcinoma (HGNEC-L), including SCLC and LCNEC, is aggressive and usually treated according to SCLC paradigms. The clinical relevance of de novo actionable genomic alterations (AGA) remains incompletely defined. Methods: We performed a retrospective multicenter analysis of advanced HGNEC-L with de novo AGA, assessing rwORR, rwDCR, rwPFS, and OS. Findings were contextualized by a structured literature review and exploratory pooled reconstructed-IPD Cox analysis, with targeted therapy modeled as a source-stratified time-dependent covariate. Results: Ten patients from four tertiary centers were included. Most were women (90.0%) and never-smokers (70.0%); histology was LCNEC in 60.0% and SCLC/mixed SCLC in 40.0%. AGA included EGFR mutations (n = 6), EML4-ALK fusions (n = 2), KIF5B-RET fusion (n = 1), and KRAS p.G12C (n = 1). Targeted-containing regimens achieved rwORR 77.8%, rwDCR 88.9%, and median rwPFS 9.0 months (95% CI, 2.0–18.7), as opposed to 3.7 months for ICI-containing regimens and 2.6 months for chemotherapy alone. Median OS for the entire cohort was 17.2 months (95% CI, 4.8–36.3); overall survival did not differ significantly between patients with and without targeted-containing exposure (19.0 vs. 17.2 months; log-rank p = 0.50). In pooled reconstructed-IPD time-dependent Cox analysis (72 patients, 39 deaths), targeted therapy showed a favorable but non-significant OS association (HR, 0.89; 95% CI, 0.31–2.56; p = 0.831), maintained directionally in the age/sex-adjusted subset (HR, 0.54; 95% CI, 0.16–1.77; p = 0.306). Conclusions: De novo AGA-positive HGNEC-L represents a clinically relevant subgroup with potential sensitivity to genotype-matched targeted therapy, supporting comprehensive molecular profiling and early targeted therapy consideration. Full article

Background/Objectives: Extrapulmonary neuroendocrine carcinoma (EPNEC) is a rare, heterogeneous malignancy with no standard second-line treatment after progression on first-line platinum-doublet chemotherapy. We compared the efficacy and safety of amrubicin (AMR) versus platinum-based doublet as second-line therapy for advanced EPNEC. Methods: This multicenter retrospective study included patients with advanced EPNEC treated at five Japanese institutions who received second-line AMR or a platinum-based doublet. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and adverse events were assessed. Results: Forty-four patients were enrolled (platinum-based doublet, n = 25; AMR, n = 19). Median OS was 6.1 months (95% confidence interval [CI], 4.9–9.0) and 6.8 months (95% CI, 2.7–13.2), and median PFS was 2.2 months (95% CI, 1.6–4.4) and 2.1 months (95% CI, 1.5–6.8), respectively. ORR and DCR were 20.0% and 32.0% in the platinum group and 5.3% and 26.3% in the AMR group, respectively. No significant differences were observed for OS, PFS, ORR, or DCR. Grade 3–4 hematologic toxicity was more frequent in the platinum group, whereas severe non-hematologic toxicity was rare in both groups. Conclusions: AMR therapy and platinum-based doublet therapy may exhibit comparable efficacy and acceptable safety profiles as second-line treatment options for advanced EPNEC. Full article

Background and Clinical Significance: Oropharyngeal squamous cell carcinoma (OPSCC) and small-cell neuroendocrine carcinoma (SCNEC) are biologically distinct entities with markedly different prognostic and therapeutic implications. While HPV-negative OPSCC carries worse outcomes than HPV-positive disease, SCNEC is exceedingly rare, highly aggressive, and prone to early systemic dissemination. Their synchronous occurrence in the head and neck (HN) is exceptional and poses major diagnostic and therapeutic challenges. Case Presentation: A 54-year-old male, smoker and alcohol consumer, presented with a left tonsillar lesion and cervical lymphadenopathy. Biopsy confirmed p16-negative OPSCC. He underwent transoral robotic surgery with modified radical neck dissection. Histopathology unexpectedly revealed two distinct malignancies: keratinizing OPSCC in the tonsil and high-grade SCNEC in a cervical lymph node, confirmed by immunohistochemistry (synaptophysin, CD56, Ki-67 80%). Postoperative FDG-PET/CT performed within two months showed rapid systemic spread, including paravertebral, pulmonary, and pelvic nodal metastases. Despite recommendation for systemic therapy, the patient deteriorated quickly and died shortly thereafter. Conclusions: This study reports coexistence of p16-negative OPSCC and high-grade SCNEC in the HN. It highlights the diagnostic complexity, staging limitations, and therapeutic dilemmas of discordant histologies, while illustrating the fulminant clinical course typical of SCNEC of unknown origin. Early recognition, comprehensive pathology, and multidisciplinary management are essential, although prognosis remains dominated by the aggressive neuroendocrine component. Full article

Background/Objectives: Antibody–drug conjugates (ADCs) targeting Nectin-4 (enfortumab vedotin) and TROP-2 (sacituzumab govitecan) have transformed the management of advanced urothelial carcinoma (UC), but evidence on their molecular targets in rare non-urothelial bladder carcinomas (N-UC) is scarce. We evaluated the immunohistochemical expression of TROP-2 and Nectin-4 in muscle-invasive UC and N-UC and assessed their association with tumour stage, nodal status and overall survival. Methods: In this retrospective single-centre study, 111 consecutive patients with primary muscle-invasive bladder carcinoma (73 UC, 38 N-UC including squamous, adenocarcinoma, neuroendocrine and sarcomatoid variants) were analysed. TROP-2 and Nectin-4 expression was quantified using the H-score; positivity was defined as ≥15. Marker expression was correlated with clinicopathological characteristics and overall survival (OS) using chi-squared, linear-by-linear, log-rank, and Cox regression analyses. Results: TROP-2 positivity was observed in 46.6% of UC and 36.8% of N-UC (p = 0.925); Nectin-4 positivity in 17.8% and 28.9%, respectively (p = 0.275). Among positive cases, TROP-2 H-scores were higher in N-UC than in UC (mean 109 vs. 70; Mann–Whitney p = 0.045; Cliff’s delta 0.37, 95% CI 0.05–0.66); as no adjustment for multiple testing was applied, this difference is regarded as nominally significant and exploratory. Nectin-4 H-scores were numerically higher in UC (mean 82 vs. 53) but did not reach statistical significance (p = 0.84). Across the cohort, TROP-2 expression increased with advancing T stage (linear-by-linear p = 0.026) and was associated with nodal involvement (p = 0.043). Nectin-4 showed no significant stage association. Sarcomatoid carcinomas were negative for both markers. Median OS was 41 months in UC versus 19 months in N-UC (p = 0.668). Neither marker independently predicted OS, whereas advanced T stage (p = 0.003) and nodal involvement (p = 0.021) were significantly associated with poorer survival; T stage remained independently prognostic in multivariable analysis. Conclusions: TROP-2 and Nectin-4 are expressed at comparable rates in muscle-invasive UC and rare N-UC, except in sarcomatoid variants. TROP-2 expression increased with advancing tumour stage, suggesting stage-dependent regulation in muscle-invasive disease. Therefore, both markers should be interpreted as potential therapeutic targets whose expression can be demonstrated in these tumours, rather than as prognostic biomarkers or as validated predictive biomarkers of ADC response; because no patient received an ADC, the present study cannot determine whether expression predicts clinical benefit, and this distinction requires prospective, treatment-linked evaluation that includes patients with N-UC. Full article

In 2010, the World Health Organization (WHO) standardized neuroendocrine neoplasm terminology, dividing these tumors by differentiation into well-differentiated neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas. Registries such as the Surveillance, Epidemiology, and End Results (SEER) program and the National Cancer Database (NCDB) store legacy codes predating this framework, raising concern that registry-based research carries nomenclature errors into the clinical literature. We performed a scoping review of research published in 2012–2022 that used SEER and/or the NCDB to study gastroenteropancreatic neuroendocrine tumors, charting 170 articles (from 1079 citations) against the 2010 classification, with forward citation analysis (OpenAlex, Semantic Scholar) measuring downstream citation exposure. Of 141 assessable studies, 88% (n = 124) applied the nomenclature inaccurately: 82.3% included poorly or undifferentiated neoplasms within neuroendocrine tumor cohorts (mean 18.7% of the cohort) and 9.9% conflated database differentiation grade with WHO proliferation grade; appropriate usage did not improve over time. These discordant studies accumulated 7323 citations across 5145 works, with 87.9% cited by at least one review (1075 distinct reviews) and six cited by major guidelines (NCCN, ESMO, ENETS). Across research published from 2012 to 2022, nomenclature discordance was widespread, persistent throughout the study period, and present in studies frequently cited by the secondary and guideline literature. Because these cohorts incorporate more aggressive and poorly or undifferentiated neoplasms, their aggregate outcome estimates are likely biased toward a poorer prognosis, potentially overstating the aggressiveness of well-differentiated neuroendocrine tumors, particularly for prognostic estimates; this review characterized cohort composition rather than quantifying the effect on any individual study’s outcomes, and whether this bias has, in turn, affected clinical decision-making was not assessed here and remains a hypothesis for future work. Journals and guideline panels should require explicit alignment with current WHO definitions for registry-based studies. Full article

Liver transplantation (LT) has evolved from a treatment for end-stage benign liver disease into a therapeutic strategy for selected oncological indications, including hepatocellular carcinoma (HCC), unresectable colorectal liver metastases (CRLM), hepatoblastoma, neuroendocrine tumor hepatic metastases, and hepatic epithelioid hemangioendothelioma. As the indications for LT expand and post-transplant survival improves, pulmonary recurrence has emerged as the predominant pattern of extrahepatic relapse across histologies. Yet no standardized surgical guidelines exist for managing lung metastases in the post-transplant patient. This narrative review synthesizes the available evidence on pulmonary metastasectomy following LT, addressing the incidence and tumor-specific patterns of pulmonary recurrence, the influence of immunosuppression on metastatic biology, surgical indications and contraindications, approach and timing considerations, and patient selection across primary histologies. We propose a practical decision-making framework integrating primary tumor biology, disease-free interval, lesion characteristics, immunosuppression regimen, and systemic therapy response. With the recent regulatory recognition of CRLM as a standard transplant indication and the ongoing SECA-III randomized trial, the downstream surgical management of pulmonary recurrence in LT recipients requires urgent evidence-based codification. Full article

Background: Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous neuroendocrine malignancy. Like cutaneous malignant melanomas, a subset of MCCs can clinically present without an identifiable primary tumour, termed Merkel cell carcinoma of unknown primary (UPMCC), with incompletely understood behaviour and prognosis. Our objectives are to evaluate the clinical presentation, management and survival outcomes in UPMCC and compare overall survival with metastatic MCC of known-primary origin. Methods: A retrospective review of 252 consecutive MCC patients (1992–2023) identified 20 cases of histologically confirmed nodal or metastatic UPMCC. Demographics, anatomical distribution, treatment and oncological outcomes were analysed. Overall survival was compared with patients presenting with metastatic MCC of known primary. Results: The cohort included 15 males and 5 females (mean age 76 years). Presentation most commonly involved inguinal (n = 7) and axillary (n = 6) nodes, followed by parotid and cervical basins (n = 4). Management was multimodal, including lymphadenectomy, radiotherapy and systemic therapy. Six patients remained disease-free at a mean follow-up of 63.3 months. The mean overall survival was 43.65 months for UPMCC versus 39.29 months for known-primary metastatic MCC. Conclusions: UPMCC most commonly presents as inguinal or axillary nodal disease. Survival outcomes suggest a trend toward improved prognosis compared to known-primary metastatic MCC. Full article

Background and Objectives: Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is an emerging minimally invasive therapeutic option for pancreatic and selected extra-pancreatic lesions. However, its clinical adoption is limited by heterogeneous indications, non-standardized techniques, and variable quality of evidence. This systematic review assessed the published literature on EUS-RFA and classified available evidence according to the Oxford Centre for Evidence-Based Medicine levels of evidence. Materials and Methods: A systematic search was performed to identify peer-reviewed studies reporting clinical or translational data on EUS-RFA. Studies were grouped by indication, including pancreatic insulinoma, non-functioning pancreatic neuroendocrine neoplasms, branch-duct intraductal papillary mucinous neoplasms and other pancreatic cystic neoplasms, pancreatic ductal adenocarcinoma, pancreatic metastases, adrenal adenoma, and miscellaneous indications. Each study was categorized according to Oxford level of evidence based on study design. Results: Thirty-seven records were included in the final evidence map, comprising 36 clinical studies classifiable according to Oxford levels of evidence and one translational record not classifiable as clinical therapeutic evidence. Among the 36 clinically classifiable studies, one provided Level 1b evidence, consisting of a randomized trial evaluating EUS-guided celiac ganglion RFA for pancreatic cancer-related pain palliation, and three provided Level 2b evidence, including non-randomized comparative cohorts in pancreatic insulinoma and unresectable pancreatic ductal adenocarcinoma. Most clinically classifiable studies were Level 4 evidence (32/36), mainly uncontrolled prospective or retrospective cohorts and case series. One preclinical/translational study was not classifiable within clinical therapeutic evidence levels. Pancreatic insulinoma was the most evidence-supported tumor-ablation indication, with comparative data suggesting efficacy comparable to surgery and a more favorable safety profile. For non-functioning pancreatic neuroendocrine neoplasms, branch-duct IPMN, renal cell carcinoma pancreatic metastases, and adrenal adenomas, available data suggest feasibility and encouraging short-term outcomes but remain predominantly non-comparative. In pancreatic ductal adenocarcinoma, EUS-RFA remains investigational as an adjunct to systemic therapy. Conclusions: EUS-RFA is a promising therapeutic platform, but evidence remains highly indication-dependent and dominated by low-level observational studies. Standardized protocols, indication-specific outcomes, prospective registries, and comparative trials are needed. Full article

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin malignancy characterized by high mortality and a rising incidence. Although immune checkpoint inhibitors have significantly improved patient outcomes, many patients exhibit primary or acquired resistance, frequently in the setting of an immunosuppressive tumor microenvironment (TME) enriched for myeloid populations. This review synthesizes current evidence and proposes a testable model in which nicotinic acetylcholine receptor (nAChR) signaling may intersect with tumor-associated macrophage (TAM) biology to reinforce immune exclusion in MCC. Direct MCC-specific evidence currently supports nAChR-subunit expression in tumor tissues and the association of CD163⁺/CD14⁺/S100A8⁺ myeloid populations with resistance to PD-1 pathway blockade; however, functional nAChR signaling in MCC tumor cells, TAMs, or dendritic cells has not yet been demonstrated. We therefore distinguish established MCC observations from mechanistic hypotheses extrapolated from macrophage biology, cholinergic anti-inflammatory signaling, and other cancer models. Within this framework, α7-nAChR signaling on TAMs may activate the cholinergic anti-inflammatory pathway and favor suppressive myeloid states, whereas α3- and α5-containing receptors detected in MCC tumor cells may represent tumor-cell-associated candidates for future mechanistic testing. By integrating evidence on TAM plasticity, spatial immune exclusion, and cholinergic signaling, we propose that the nAChR–macrophage axis is a rational but unproven therapeutic hypothesis that warrants systematic validation in MCC models. Full article

Rare subtypes of gastroesophageal malignancies represent a small but biologically meaningful fraction of upper gastrointestinal cancers. Although most therapeutic algorithms are derived from conventional squamous cell carcinoma and adenocarcinoma, uncommon entities such as variants of squamous cell carcinoma, lymphoepithelioma-like carcinoma, adenosquamous carcinoma, neuroendocrine carcinoma, and others display distinct clinicopathologic, immunologic, and molecular features that may influence prognosis and therapeutic decision-making. This review synthesizes current evidence regarding the epidemiology, histopathology, molecular alterations, and emerging therapeutic vulnerabilities across these rare subtypes. Importantly, these tumors frequently exhibit aggressive clinical behavior and are often managed by extrapolation from more common histologies due to the absence of prospective data. Increasing integration of genomic profiling, immune characterization, and biomarker-driven stratification is essential to refine diagnoses, expand precision therapeutic strategies, and improve outcomes. Recognition of these rare subtypes in routine practice is critical, as even small molecularly defined populations may carry disproportionate biological and translational significance within oncology. Full article

Neuroendocrine neoplasms (NENs) are a heterogeneous family of tumors that have traditionally been regarded as “immune cold” and largely refractory to PD-1/PD-L1 checkpoint blockade, with notable exceptions such as Merkel cell carcinoma (MCC). The advent of single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics has enabled unprecedented dissection of the NEN tumor microenvironment (TME), but a cross-subtype synthesis is lacking. This review aims to integrate single-cell and spatial transcriptomic findings across major NEN subtypes to reframe NEN immunosuppression and delineate translational implications. To this end, we performed a structured narrative review of PubMed-indexed studies up to 30 April 2026, prioritizing original human scRNA-seq, single-nucleus RNA-seq, spatial transcriptomic, and spatial proteomic studies of NENs, supplemented by mechanistic, clinical, and biomarker-focused reports providing essential context. Across these studies, synthesis spanning pancreatic, pulmonary, gastrointestinal, cutaneous, pituitary, adrenal, and other NEN subtypes highlights conserved features beyond the PD-1/PD-L1 axis, including myeloid-dominated infiltration with alternative checkpoints (VISTA, TIM-3, Galectin-9), cancer-associated fibroblast-mediated immune exclusion, lineage-state-dependent immune visibility, and direct immunomodulation by neuroendocrine secretory products such as calcitonin gene-related peptide. We propose a four-layer framework integrating these mechanisms and linking them to emerging biomarkers and therapies, including DLL3-directed bispecifics, alternative checkpoint inhibitors, stromal-targeting agents, and peptide receptor radionuclide therapy combinations. Together, these findings indicate that single-cell and spatial transcriptomic studies reframe NEN immunosuppression as a multilayered, subtype-dependent process, providing a conceptual scaffold for biomarker-guided, subtype-adapted therapeutic strategies and prospective clinical trial design in neuroendocrine oncology. Full article

Histological subtypes of bladder cancer are generally associated with more aggressive disease, higher stage at presentation, and worse prognosis compared to conventional urothelial carcinoma. Recent updates in classification systems have further refined the distinction between true histologic subtypes and divergent differentiation, underscoring the complexity of these tumors. Emerging molecular profiling studies have identified subtype-specific genomic alterations, including ERBB2 amplification in micropapillary subtype carcinoma, CDH1 loss in plasmacytoid subtype carcinoma, and TP53 and RB1 co-alterations in neuroendocrine bladder cancer, which may contribute to differences in tumor biology and therapeutic response. Despite these advances, the histological subtypes of bladder cancer remain underrepresented in prospective clinical trials, leading to significant gaps in evidence-based management. Treatment responses vary widely across subtypes, with some demonstrating sensitivity to platinum-based chemotherapy or immunotherapy, while others appear less responsive to conventional approaches. This review summarizes the current understanding of the epidemiology, molecular landscape, and clinical behavior of major bladder cancer subtypes and highlights emerging opportunities for personalized treatment strategies, biomarker-driven therapies, and more inclusive clinical trial design to improve outcomes in this high-risk population. Full article

The widespread adoption of prostate-specific membrane antigen (PSMA)-targeted PET/CT has profoundly reshaped molecular imaging in prostate cancer and has substantially reduced the routine use of radiolabeled choline tracers. However, the transition from choline to PSMA imaging should not be interpreted simply as the replacement of one radiopharmaceutical by another, but rather as part of a broader evolution from metabolism-based imaging toward receptor-targeted and biology-driven imaging strategies. This narrative review critically reassesses the residual and emerging role of choline PET/CT in the PSMA era, with particular attention to the biological rationale of choline uptake, selected prostate cancer scenarios, and extra-prostatic applications. In prostate cancer, PSMA PET/CT remains the dominant imaging modality because of its superior diagnostic performance, particularly in biochemical recurrence; nevertheless, choline PET/CT may provide complementary metabolic information in highly selected settings, including PSMA-low or heterogeneous disease, aggressive or dedifferentiated variants, neuroendocrine transformation, equivocal PSMA findings, and limited PSMA availability. These prostate cancer applications, however, are supported mainly by biological rationale, indirect evidence, and limited clinical data and should therefore be regarded as exploratory rather than established indications. By contrast, ¹⁸F-fluorocholine PET/CT has emerged as a clinically established imaging modality in primary hyperparathyroidism, particularly after negative or inconclusive conventional imaging, with prospective studies and meta-analyses demonstrating high detection rates and superior performance compared with conventional scintigraphic techniques. Additional applications in hepatocellular carcinoma and selected neuro-oncologic settings remain exploratory and require further validation. Overall, choline PET/CT should not be considered obsolete in the PSMA era, but selectively repositioned within biology-driven and multiparametric imaging strategies, with its strongest evidence currently supporting primary hyperparathyroidism and its other applications requiring cautious interpretation and further prospective validation. Full article

Background/Objectives: Anaplastic lymphoma kinase (ALK) fusion is a driver gene translocation detected in 3–5% of patients with non-small-cell lung cancer (NSCLC). Next-generation sequencing (NGS)-based tests are the standard of care for detecting actionable gene alterations; however, false negatives remain a concern. Immunohistochemical staining is another reliable, rapid, and low-cost method for detecting ALK fusions. Previous studies have reported high concordance with NGS, although further studies are needed to draw definitive conclusions. Methods: A retrospective analysis was conducted on consecutive patients with NSCLC who were tested using the Oncomine Dx Target Test (ODxTT), an amplicon-based DNA and RNA NGS test for NSCLC, and ALK-immunohistochemistry (IHC) at our institution between 8 August 2019 and 11 April 2025. Results: Of 919 eligible patients included in this study, ALK fusion was detected in 30 (3.26%) patients, whereas ALK-IHC was positive in 35 (3.80%) patients. The concordance and κ coefficient of the two tests were 99.4% and 0.920, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of ALK-IHC for ODxTT were 100%, 99.4%, 85.7%, and 100%, respectively. Five discordant patients were NGS negative and IHC positive. Among the five discordant cases, one had a false-negative NGS result, whereas the remaining four had false-positive ALK-IHC results, including three patients with neuroendocrine carcinomas. Conclusions: ALK-IHC shows diagnostic accuracy comparable to ODxTT, although prudent interpretation is needed for patients without adenocarcinoma. Our findings suggest the complementary role of ALK-IHC alongside NGS-based testing, particularly in patients with a high pre-test probability of harbouring ALK fusions. Full article

Background: Head and neck neuroendocrine carcinoma (HN-NEC) is exceedingly rare. Standardized treatment strategies for this malignancy remain unestablished. This study aimed to explore promising treatment modalities, and to identify prognostic factors in HN-NEC. Materials and Methods: Thirty-nine patients diagnosed with HN-NEC at West China Hospital of Sichuan University between 2006 and 2025 were enrolled. The 5-year survival rates were estimated by Kaplan–Meier analysis. The log-rank test and Firth’s penalized Cox multivariable analysis regression model were used to identify prognostic factors. Results: The 5-year locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS), and overall survival (OS) rates for patients who did and did not receive radiotherapy were 63.2% vs. 29.6% (p = 0.031), 75.5% vs. 48.0% (p = 0.065), and 81.4% vs. 46.9% (p = 0.039), respectively. Laryngeal NEC was associated with poorer 5-year DMFS (41.2% vs. 87.5%, p = 0.023) and 5-year OS (38.1% vs. 92.9%, p = 0.027) compared with non-laryngeal HN-NEC. Radiotherapy (HR = 0.152, 95% CI: 0.025–0.757, p = 0.022) was a potentially protective factor influencing LRRFS. Conclusions: Radiotherapy may be associated with improved LRRFS in patients with HN-NEC. HN-NEC originating in the larynx appeared to be associated with a poorer prognosis compared with other primary sites of the head and neck. Full article