Search Results (1,988)

Background/Objectives: Cancer-associated fibroblasts (CAFs) play a pivotal role in the tumor microenvironment. We conducted an analysis using RNA sequencing to identify specific markers for CAFs compared to normal fibroblasts (NFs) in non-small-cell carcinoma (NSCLC). Methods: CAFs and NFs were isolated and cultured from tumor tissues (primary tumor or metastatic lymph nodes) and matched non-tumor tissues, respectively. Bulk RNA sequencing was conducted on isolated CAFs and normal fibroblast NFs. Differential expressions, gene set enrichment, and CAF subpopulation prediction analyses were performed. Results: During the study period, 27 CAFs and 12 NFs were isolated and cultured from tumor and non-tumor tissues in patients with treatment-naïve NSCLC. Among them, 22 CAFs and 11 NFs were included in the RNA sequencing analysis. The 22 CAF samples consisted of 12 adenocarcinomas and 10 squamous cell carcinomas (SqCC), with 16 samples from the lungs and 6 samples from the lymph nodes. Notably, COL11A1, GREM1, CD36, and GAS6 showed a higher expression in CAFs than in NFs, whereas TNC and CXCL2 were more abundantly expressed in NFs. CD36 levels were elevated in CAFs from lymph nodes (LN-CAFs) compared with those from lung specimens (Lung-CAFs) and NFs. COL11A1 levels in Lung-CAFs surpassed those in LN-CAFs and NFs. Both GREM1 and GAS6 showed a strong expression in Lung-CAFs and LN-CAFs relative to NFs. CAFs exhibited features of the myofibroblast CAF subpopulation, whereas NFs displayed traits of the antigen-presenting CAF subtype. In the co-culture model of CAFs and THP-1 cells, the knockdown of GREM1 or GAS6 in CAFs significantly decreased the M2 marker expression in macrophages. Conclusions In NSCLC, GREM1 and GAS6 can be valuable diagnostic targets for CAFs from primary tumors and metastatic sites; they warrant further study. Full article

Breast cancer (BC) remains a leading cause of cancer-related mortality in women. Extracellular matrix (ECM) remodeling is a critical modulator of tumor invasion and metastasis. Three-dimensional (3D) cell culture models have been proposed as advanced systems better mimicking the tumor microenvironment (TME), potentially offering enhanced insights into underlying mechanisms compared to conventional two-dimensional (2D) cultures. This study highlights how BC cells develop metastatic potential and tumor progression independently from ECM contact using advanced 3D spheroid culture models compared to traditional 2D cultures in triple-negative breast cancer (TNBC) cell lines. Spheroids were formed using ultra-low adhesion plates, and their morphological and functional properties were assessed via phase-contrast and scanning electron microscopy (SEM), along with functional assays. Both cell lines formed compact spheroids exhibiting mesenchymal-to-epithelial transition (MET) characteristics. Functional assays showed enhanced cell migration and dissemination of spheroid-derived cancer cells. Gene expression profiling revealed increased expression of ECM remodeling enzymes, cell surface receptors, and adhesion molecules in 3D cultures compared to 2D. MicroRNA analysis highlighted distinct regulatory patterns specifically associated with metastasis and epithelial-to-mesenchymal transition (EMT). These findings demonstrate that 3D spheroid models effectively recapitulate the complexity of TNBC, providing valuable insights into ECM dynamics, epigenetic regulation, and metastatic behavior and potentially guiding improved therapeutic strategies. Full article

Retinoblastoma is a rare but malignant pediatric retinal tumor, affecting 1 in 15,000–20,000 live births annually. It arises from biallelic mutations in the RB1 tumor suppressor gene (chromosome 13q14.2), leading to uncontrolled cell cycle progression. Clinically, it presents as unilateral (60%) or bilateral (40%) disease, with leukocoria and strabismus as hallmark signs. Untreated, retinoblastoma is fatal due to metastatic spread. The disease follows Knudson’s two-hit model: heritable forms (30–40% of cases) involve a germline RB1 mutation (M1) and a somatic second hit (M2), predisposing to bilateral/multifocal tumors and secondary cancers. Non-heritable cases (60–70%) result from somatic RB1 mutations or, rarely, MYCN amplification (2%). Genetic testing is critical to classify risk (H0, H1, and HX categories), guide surveillance, and inform family counseling. Bilateral cases almost always harbor germline mutations, while 15% of unilateral cases may carry germline/mosaic RB1 defects. Advanced techniques (Sanger/NGS sequencing for mutation detection, NGS for copy number alterations, and methylation assays) detect RB1 mutations, CNVs, and epigenetic silencing. Tumor DNA analysis resolves ambiguous cases. H1 patients require intensive ocular and brain MRI surveillance, while H0 cases need no follow-up. Prenatal/preimplantation genetic diagnosis (PGD) can prevent transmission in high-risk families. Emerging research explores additional genes (BCOR, CREBBP) and MYCN-amplified subtypes. Genetic counseling addresses recurrence risks, reproductive options, and long-term cancer monitoring. Integrating genetic insights into clinical practice enhances precision medicine, reducing morbidity and healthcare costs. Future directions include whole-genome sequencing and functional studies to refine therapeutic strategies. Full article

Background and Objectives: Resistance to immune checkpoint inhibitors (ICIs) reduces treatment efficacy in 40–65% of patients. The ability to predict this at the outset of therapy could help optimise treatment selection and improve patient survival. The aim of this study was to identify factors associated with primary resistance to PD-1 inhibitors in metastatic melanoma and discover predictive markers. Materials and Methods: This retrospective study involved 110 patients with non-uveal metastatic melanoma treated with PD-1 inhibitors from 2016 to 2023. Demographic, clinical and haematological data were collected. LASSO regression was utilised to identify the best markers. Bootstrap resampling was performed for internal validation and to overcome overfitting. Results: Primary resistance occurred in 44.6% of the patients. The factors associated with resistance included elevated platelet-to-lymphocyte ratio (PLR), the presence of acral/mucosal melanoma, BRAF mutant disease, low globulin levels and ≥3 metastatic sites. An evaluation of the predictive capability of these variables showed robust discrimination, with an area under the receiver operating characteristic curve of 0.831. Conclusions: This study identified the key predictors of primary resistance to PD-1 inhibitors to be PLR, globulin levels, metastatic burden and melanoma subtype. These identified parameters may guide the early prediction of primary resistance to PD-1 inhibitors. Future work should externally validate the model and further explore robust strategies to overcome resistance. Full article

Background: Stereotactic ablative radiotherapy (SABR) is increasingly used in the treatment of localized and metastatic renal cell carcinoma (RCC), a malignancy traditionally considered radioresistant. Beyond direct cytotoxicity, SABR may promote immunogenic cell death and modulate the tumor immune microenvironment, though the underlying mechanisms remain incompletely understood. Objectives and Methods: This study examined the immunomodulatory effects of two high-dose irradiation regimens (8 Gy and 3 × 8 Gy) in an in vitro model using two RCC cell lines (ACHN, Caki-2) and peripheral blood mononuclear cells (PBMCs) from healthy donors. Results: The 3 × 8 Gy regimen more effectively reduced tumor cell viability and proliferation, particularly in ACHN cells, suggesting differential radiosensitivity. Both regimens induced secretion of IL-6, IL-8, TGF-β, and VEGF, with levels varying by cell line and dose. Caki-2 cells exhibited a cytokine profile consistent with a pro-inflammatory and potentially immunosuppressive phenotype. Conditioned media from irradiated cells were used to stimulate PBMCs, revealing divergent responses. Media from 3 × 8 Gy-irradiated ACHN cells enhanced PBMC proliferation and increased CD8⁺ T cells and CD11c⁺ monocytes, along with IFN-γ, IL-2, and TNF-α secretion, suggesting immunostimulatory effects. Conversely, media from Caki-2 cells had minimal impact on PBMC proliferation and increased TGF-β levels. Conclusions: These results indicate that high-dose irradiation can differentially modulate immune responses in RCC cell lines, depending on tumor intrinsic properties and irradiation regimen. Further in vivo studies are warranted to validate these findings and support development of SABR immunotherapy combinations guided by predictive immune biomarkers. Full article

Purpose: Evaluation of predictors and outcomes in NSCLC patients treated with an immune checkpoint inhibitor (ICI) following a severe immune-related adverse event (irAE). Methods: We included all NSCLC patients receiving ≥1 ICI cycle and corticosteroids for CTCAE Grade ≥3 irAEs between 2017 and 2023 from three UK NHS teaching hospitals. Progression-free survival (PFS) and overall survival (OS) after the 1st irAE, best overall response (BOR) to ICI, and predictors of clinical benefit were evaluated. Kaplan–Meier, Cox and logistic regression models, and Wilcoxon tests were used. Results: We screened 1658 NSCLC patients and identified 80 eligible subjects. The majority of patients had metastatic (n = 50, 63%) vs. localized (n = 30, 37%) NSCLC. Most patients developed a single ≥Grade 3 irAE on 1st line ICI (n = 71, 89%). Overall, 14 (18%) patients developed 2nd irAEs, 7 after rechallenge with ICIs. In the complete cohort, median OS after 1st irAE was 15.84 months (95% CI, 12.45–26.91). Lower neutrophil-to-lymphocyte ratio (NLR), patients receiving >4 cycles of ICI or median duration of ICI of >2.76 months before 1st irAE were associated with improved OS (p < 0.05), the latter two with PFS (p < 0.05). Age, gender, stage, KRAS mutation, PD-L1 and ICI type were not associated with PFS or OS. Pneumonitis as 1st irAE had the worst PFS and OS (p < 0.05). Median starting corticosteroid dose of ≤60 mg for 1st irAE had an improved OS (p = 0.04). Post 1st irAE response associated with better PFS and OS (p < 0.05). Number and duration of irAEs and additional immunosuppressive agents (14% of patients) were not associated with PFS or OS. Conclusions: In ≥Grade 3 irAEs patients managed with corticosteroids, lower baseline NLR, longer ICI use, response to ICI after 1st irAE, and a ≤60 mg corticosteroid dose had promising outcomes. Full article

Background: Metastasis continues to be a leading cause of mortality in osteosarcoma (OS) among pediatric and young adult populations, with few effective therapeutic options available. Despite immunotherapy advancements, its efficacy in OS is hindered by an incomplete understanding of the immunosuppressive tumor microenvironment (TME). Methods: We utilized multiplex imaging mass cytometry and phenoplexing to characterize immune and stromal cell populations within the TME of a tissue microarray comprising 51 primary OS tumors. The prognostic significance of TME cell abundance and spatial cell–cell distance was evaluated using Kaplan–Meier and Cox regression analyses. To investigate macrophage functionality in vivo, we employed orthotopic xenograft mouse models by co-injecting THP-1-derived M0 or M2 macrophages with 143B OS cells to assess their impact on tumor growth and pulmonary metastasis. Mechanisms of macrophage-mediated metastasis were explored using Luminex, ELISA, and transwell migration assays. Results: Our results showed that macrophages dominated the TME, with M0 and M2 subtypes significantly outnumbering M1 macrophages (M1) and other myeloid cells. T cells and myeloid-derived suppressor cells (MDSC) were the second and third most abundant immune populations, respectively. Among stromal cells, endothelial cells predominated over fibroblasts. While individual immunosuppressive cell populations (M2, MDSC, and Treg) showed no direct correlation with clinical outcomes, the collective abundance of M2 and MDSC was significantly associated with reduced metastasis-free survival (MFS, p = 0.0244) and recurrence-free survival (RFS, p = 0.0040). Notably, closer spatial proximity between M2 macrophages and immunosuppressive cells (p = 0.0248) or Ki-67⁺ cells (p = 0.0321) correlated with decreased MFS, suggesting the formation of an M2-centric immunosuppressive and pro-tumor hub. In vivo, co-injection of M2 macrophages with 143B cells significantly enhanced pulmonary metastasis (p = 0.0140). Luminex analysis identified M2-derived MIP-1α (CCL3) as a candidate chemokine driving OS cell metastatic potential. Conclusions: This study provides a high-resolution map of the OS TME, highlighting the prognostic significance of M2 and immunosuppressive cell interactions in driving metastasis, potentially through MIP-1α signaling. These findings establish a foundation for developing targeted immunotherapies to improve outcomes in metastatic OS. Full article

Objectives: Personalized sepsis care requires understanding how pre-existing health status can influence outcomes. The aim of this study is to evaluate its impact on in-hospital and 12-month mortality in patients with sepsis, taking into account age, comorbidities, the Charlson Comorbidity Index, frailty, anemia, and the Sequential Organ Failure Score Assessment (SOFA) in the first 24 h. Methods: An observational and retrospective study was conducted using data from the Sepsis Code program at the Hospital Universitario de La Princesa. The relationship between risk factors and mortality, as well as Intensive Care Unit (ICU) admission, was analyzed for the period 2016–2018 using bivariate and multivariate logistic regression. Results: A total of 547 patients were included. In the multivariate analysis, the risk factors independently associated with mortality were Rockwood Clinical Frailty Scale ≥ 5 (OR 2.45, p < 0.05); SOFA ≥ 4 (OR 2.13, p < 0.05); age (OR 1.98, p < 0.05); anemia (OR 1.85, p < 0.05); and specific comorbidities such as ischemic heart disease (OR 2.34, p < 0.05), severe liver disease (OR 3.62, p < 0.05), and metastatic cancer (OR 3.14, p < 0.05). Patients who were frail, had dementia, or heart failure were less likely to be admitted to the ICU. Conclusions: Frailty, comorbidities, age, and anemia are associated with outcomes in patients with sepsis and could be incorporated into mortality prediction models to guide tailored treatment strategies. Full article

In breast cancer, progression from localized stage I to distant metastatic stage IV disease is associated with a reduction of 5-year survival from nearly 100% to 23.2%. Expression of the calcium-activated protease isoforms calpain-1 and calpain-2 has been correlated with cell migration and invasion in vitro, metastatic potential in preclinical mouse models of cancer, and breast cancer prognosis in patients. It is unclear which of these two calpain isoforms is responsible for the apparent metastatic potential of cancer cells. Here, we demonstrate that while individual CRISPR-Cas9 knockouts of either CAPN1 or CAPN2 genes (encoding the catalytic subunits of calpain-1 and -2, respectively) reduce in vitro migration and marginally suppress in vivo metastasis, genetic disruption of both calpain-1 and calpain-2 through knockout of the CAPNS1 gene (encoding the common regulatory subunit of calpain-1 and -2) diminishes metastasis by 83.4 ± 13.6% in a mouse xenograft model of human triple-negative breast cancer. The effect of calpain-1/2 deficiency was replicated in vitro with a modified cell-permeable calpastatin (CAST)-based peptide inhibitor (cell migration reduced to 53.5 ± 11.0% of vehicle control). However, this peptide inhibitor was not effective in vivo at reducing metastasis under the conditions used (vehicle vs. CAST, 1.12 ± 1.35 lung metastases per mm² vs. 0.34 ± 0.20 metastases per mm²), likely due to rapid clearance, as indicated by the short serum half-life. This work demonstrates that calpain-1/2 disruption effectively abrogates metastasis and provides rationale for development of effective calpain inhibitors. Full article

Background and Objectives: Systemic inflammatory markers from an ordinary complete blood count (CBC) may foreshadow where non-small-cell lung cancer (NSCLC) will first spread, but organ-specific signatures remain poorly defined. Materials and Methods: We retrospectively reviewed 302 adults (mean age 60.7 ± 13.4 years; 80.8% men) with stage IV NSCLC managed at OncoHelp Medical Center, Timișoara, between January 2022 and December 2024. Eligibility demanded a single radiologically confirmed distant site at diagnosis and pre-treatment CBC. Neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR), and lymphocyte-to-monocyte (LMR) ratios were compared across pleural (n = 52), bone (n = 86), liver (n = 66), and brain (n = 98) metastases using Kruskal–Wallis tests with Bonferroni adjustment; z-standardized logistic models identified independent predictors. Results: Metastases clustered most often in brain (32.5%), followed by bone (28.5%), liver (21.9%), and pleura (17.2%). Median PLR rose selectively in pleural disease (274 vs. 217–253 in other sites; p = 0.006). LMR fell to 2.0 in bone but climbed to 2.8 in brain lesions (p = 0.032 and 0.008, respectively). NLR was globally elevated (6.7–7.6), yet differed significantly only for bone and liver deposits. Logistic modeling showed that each standard-deviation rise in absolute neutrophil count quadrupled the odds of hepatic involvement (Odd Ratio (OR) 4.26; 99% Confidence inerval (CI) 2.20–6.25), monocytosis nearly doubled bone risk (OR 1.83; 1.01–3.33), while higher erythrocytes, eosinophils, and lymphocytes independently protected against pleural seeding (all p < 0.01). Age-stratified analysis revealed that osseous and cerebral metastases predominated in patients ≤ 50 years, whereas inflammatory indices were age-invariant. Conclusions: Routine CBC ratios encode distinct “inflammatory fingerprints” that mirror the first metastatic destination in NSCLC: platelets herald pleural spread, neutrophils favor liver and bone, and divergent lymphocyte–monocyte balances separate bone from brain. Although no substitute for cross-sectional imaging, these low-cost markers could refine clinical suspicion, guide targeted work-up, and illuminate the biology of organ-selective dissemination, particularly in resource-limited settings. Full article

Background/Objective: At least 25% of colorectal cancer (CRC) patients develop liver metastases (CRLM), and chemotherapeutic regimens based on the fluoropyrimidine (FP) drug 5-fluorouracil (5-FU) provide a survival advantage, but long-term survival is uncommon. The primary molecular target of FP drugs is thymidylate synthase (TS). Methods: A TS/Top1 dual-targeting cytotoxic mechanism for CF10/LV was confirmed by TS ternary complex detection by Western blot and by immunofluorescence detection of Top1 cleavage complexes. CF10/LV activated the ATR/Chk1 pathway consistent with enhanced replication stress and induced apoptosis. In vivo studies showed CF10 and CF10/LV eradicated liver metastasis in a CRLM model without scarring or weight loss, displaying therapeutic advantages relative to legacy FPs. Results: We demonstrated that a nanoscale FP polymer, CF10, displayed greater potency than expected based on FP content in part through more direct conversion to the TS-inhibitory metabolite, FdUMP. In this study, we tested CF10 for potency advantages relative to 5-FU and trifluorothymidine (TFT, the FP component of TAS-102) and confirmed a general potency advantage for CF10 in CRC cell lines in the Broad Institute PRISM screen. We demonstrated that this potency advantage is retained in CRC cells cultured with human-like folate levels and is enhanced by LV co-treatment to a similar extent as that by 5-FU. Our results confirm CF10 development proceeding as a CF10/LV combination. Mechanistically, CF10 cytotoxicity closely correlates with poisons of DNA topoisomerase 1 (Top1) in the PRISM screen relative to 5-FU and TFT. Conclusions: Our pre-clinical data support an early-phase clinical trial for CF10 for treating liver-metastatic CRC. Full article

Background: Melanoma of unknown primary (MUP) is a rare and distinct clinical subtype of metastatic melanoma, in which no identifiable primary tumor is found. The prognosis of MUP compared to melanoma with known primary (MKP) remains unclear, especially in the era of novel therapies like immune checkpoint inhibitors (ICIs) and targeted therapies. This meta-analysis aims to compare the overall survival (OS) of MUP and MKP patients under these therapies. Methods: This systematic review was conducted in line with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). A systematic search of major databases was conducted, yielding six eligible studies (nine study arms) that assessed the survival outcomes of MUP and MKP patients treated with immunotherapies and targeted therapies. We pooled the hazard ratios (HRs) for OS using both fixed and random effects models. Heterogeneity was assessed with the I² statistic followed by a Baujat plot, and publication bias was evaluated using funnel plots and Egger’s test. Results: Our analysis revealed a borderline significant HR of 0.90 (95% CI: [0.81, 1.00], p = 0.04) under the fixed effect model, suggesting a potential survival benefit for MUP patients. However, the random effects model, accounting for study heterogeneity, showed no significant difference in OS between MUP and MKP (HR = 0.87, 95% CI: [0.73, 1.05], p = 0.15). Significant heterogeneity (I² = 66.9%, p = 0.0022) was observed across studies. No substantial publication bias was detected. Conclusion: While the trend observed in the fixed effect model suggests a potential benefit for MUP patients, the random effects analysis indicates no significant difference between MUP and MKP in terms of OS. These findings underscore the importance of accounting for study heterogeneity and highlight the need for further prospective studies to better understand the impact of novel therapies on MUP. Full article

(1) Background: The presence of metastatic disease significantly increases the risk of venous thromboembolism (VTE) in breast cancer, particularly during chemotherapy. Although not categorized as a highly thrombogenic malignancy, the elevated global prevalence of this cancer places a substantial number of patients at risk of thrombosis, which cannot yet be accurately predicted by validated risk assessment models (RAMs), highlighting the need for a dedicated model. (2) Aim: This study aims to develop a RAM for VTE in newly diagnosed metastatic breast cancer patients enrolled in a prospective, observational, and multicenter study. (3) Methods: A cohort of 189 patients beginning antitumor therapy were enrolled and prospectively monitored for VTE and mortality. Blood samples collected at enrollment were tested for D-dimer, fibrinogen, FVIII, prothrombin fragment 1 + 2 (F1 + 2), and thrombin generation (TG). Competing risk analyses were performed to identify significant predictors. (4) Results: Within one year, the cumulative incidences of VTE and mortality were 7.0% and 12%, respectively. Univariable analysis identified high Ki-67, D-dimer, FVIII, fibrinogen, and TG levels, along with low hemoglobin levels, as independent predictors of VTE. Only Ki-67, fibrinogen, FVIII, and hemoglobin were retained as significant predictors in multivariable analysis. These variables were further examined by multiple linear regression, which revealed Ki-67 and fibrinogen as the most significant parameters. A continuous RAM was then developed based on Ki-67 and fibrinogen (c-statistics 0.78), categorizing patients into low-risk and high-risk groups for VTE (2% vs. 13%; SHR 3.6, p = 0.018). This stratification could not be achieved using currently validated models for VTE risk. (5) Conclusions: We developed an accurate RAM for VTE that enables the identification of metastatic breast cancer patients at high risk for VTE, which supports clinicians in personalized thromboprophylaxis strategies if externally validated. Full article

Background: Spinal metastasis is the third most common site for metastatic localization, following the lung and liver. Manual detection through imaging modalities such as CT, MRI, PET, and bone scintigraphy can be costly and inefficient. Preliminary artificial intelligence (AI) techniques and computer-aided detection (CAD) systems have attempted to improve lesion detection, segmentation, and treatment response in oncological imaging. The objective of this review is to evaluate the current applications of AI across multimodal imaging techniques in the diagnosis of spinal metastasis. Methods: Databases like PubMed, Scopus, Web of Science Advance, Cochrane, and Embase (Ovid) were searched using specific keywords like ‘spine metastases’, ‘artificial intelligence’, ‘machine learning’, ‘deep learning’, and ‘diagnosis’. The screening of studies adhered to the PRISMA guidelines. Relevant variables were extracted from each of the included articles such as the primary tumor type, cohort size, and prediction model performance metrics: area under the receiver operating curve (AUC), accuracy, sensitivity, specificity, internal validation and external validation. A random-effects meta-analysis model was used to account for variability between the studies. Quality assessment was performed using the PROBAST tool. Results: This review included 39 studies published between 2007 and 2024, encompassing a total of 6267 patients. The three most common primary tumors were lung cancer (56.4%), breast cancer (51.3%), and prostate cancer (41.0%). Four studies reported AUC values for model training, 16 for internal validation, and five for external validation. The weighted average AUCs were 0.971 (training), 0.947 (internal validation), and 0.819 (external validation). The risk of bias was the highest in the analysis domain, with 22 studies (56%) rated high risk, primarily due to inadequate external validation and overfitting. Conclusions: AI-based approaches show promise for enhancing the detection, segmentation, and characterization of spinal metastatic lesions across multiple imaging modalities. Future research should focus on developing more generalizable models through larger and more diverse training datasets, integrating clinical and imaging data, and conducting prospective validation studies to demonstrate meaningful clinical impact. Full article

Calprotectin, a heterodimer of the S100A8 and S100A9 proteins, has been implicated in cancer-related inflammation and metastasis. Its role in melanoma progression, particularly in organ-specific metastasis, remains underexplored. In this retrospective study, plasma calprotectin levels were measured in 201 individuals, including healthy controls (n = 22), melanoma patients without evidence of metastasis (n = 71), and patients with metastatic melanoma (n = 108). Calprotectin concentrations were determined using the ELISA assay. Receiver operating characteristic (ROC) curve analyses were used to evaluate its diagnostic value, both alone and in combination with established biomarkers S100B and LDH. Plasma calprotectin levels were significantly elevated in patients with metastatic melanoma compared to non-metastatic patients (p < 0.001). Calprotectin showed moderate diagnostic value (AUC = 0.672), which improved to 0.755 when combined with S100B and LDH. Organ-specific analysis revealed that patients with liver metastases exhibited the highest calprotectin concentrations, with good discriminatory power (AUC = 0.710). No significant association was found between calprotectin levels and the type of metastasis identified (lymphatic vs. hematogenous). Logistic regression analysis showed that calprotectin levels above 2728 ng/mL were associated with a 7.4-fold increased risk of liver metastasis. Calprotectin is a promising blood-based biomarker that may enhance the detection of metastatic melanoma, particularly in cases with liver involvement. These findings suggest that calprotectin could be integrated into multivariable prediction models to improve risk stratification in clinical practice. Full article