Cancers

Purpose: How sarcoma subtypes engage telomerase versus alternative lengthening of telomeres (ALT), and with what consequence, is incompletely defined. Methods: We analyzed 11,792 patients with sarcoma sequenced across 19 centers in AACR Project GENIE v20.0. Telomerase activation was defined as TERT promoter mutation, amplification, or rearrangement, and ATRX/DAXX inactivation served as the ALT proxy, each assessed only where the assay interrogated the locus. Findings were tested for TERT expression in The Cancer Genome Atlas (TCGA), for overall survival (OS) in MSK-IMPACT 50K, and for replication in an independent Foundation Medicine cohort. Mendelian randomization (MR) in FinnGen tested germline telomere length. Results: Telomerase activation (8.8%) and ATRX/DAXX loss (8.0%) were mutually exclusive across subtypes (odds ratio [OR], 0.52; 95% CI, 0.29 to 0.92) and segregated by histology. In MDM2-amplified dedifferentiated liposarcoma (DDLPS), telomerase was activated through TERT amplification (17.2%) or rearrangement (2.7%), never promoter mutation (0/261), and never with ATRX/DAXX loss (0/49; P = .011). TERT-amplified tumors expressed TERT (TCGA; P = .002), and amplification was largely focal. Telomere maintenance alterations were present in 28.0% of DDLPS versus 8.7% of well-differentiated liposarcoma (P < .001) and predicted shorter OS in DDLPS (hazard ratio, 2.04; 95% CI, 1.23 to 3.39; P = .005). ATRX/DAXX loss was more frequent in uterine than extrauterine leiomyosarcoma in GENIE (adjusted OR, 1.96) and in the independent cohort (OR, 1.95; both P < .001). Genetically longer telomeres were associated with liposarcoma (OR per SD, 4.10; 95% CI, 2.15 to 7.81). Conclusion: Sarcoma telomere maintenance is histology-specific and mutually exclusive. In liposarcoma it is acquired at dedifferentiation through focal TERT amplification or ALT and identifies DDLPS with inferior survival.

Background: Neoadjuvant chemotherapy (NACT) facilitates de-escalation of breast and axillary treatment in breast cancer, but pathological responses may differ between the primary tumour and axillary lymph nodes. Understanding differential response is crucial for de-escalation strategies. Methods: This single university hospital retrospective study analysed operable breast cancers (cT1-cT3, cN0-cN3) treated with NACT (January 2013-November 2020). Two-tailed Fishers exact test or the Chi-squared test (for 2x2 comparisons) analysed concordance between breast and axillary pathological responses; Cox proportional hazards regression ascertained predictors of distant recurrence and survival; and logistic regression ascertained predictors of complete axillary response. Results: Among 413 patients (cN0=229; cN+=184) with a median age of 51, pathological response concordance between the breast and axilla was 81% (both pCR, 22.2%; concurrent residual disease, 58.8%). The cN0 group had a significantly higher ypN0 rate in breast pCR versus non-pCR (97.1% vs 80.8%, p<0.001). cN+ had axillary pCR concordant with breast pCR, compared to only 16.5% with residual breast disease. Breast pCR was the most significant predictor of axillary pCR (OR=11.6, p<0.001). Axillary pCR was highest in ER-/HER2+(66.7%) and triple-negative(46.9%) subtypes. Residual axillary disease was independently associated with the worst breast cancer-specific (HR=7.13, p=0.006) and overall Survival (HR=3.32, p=0.029). Kaplan-Meier analyses showed a trend towards worse survival outcomes with axillary residual disease, even with a breast pCR. Conclusions: In this limited series, breast pCR predicts axillary pCR in cN0 and cN+, particularly in HER2-positives and triple-negatives, supporting axillary de-escalation strategies in selected patients stratified by careful assessment of disease at the end of NACT.

Background/Objectives: In high-grade serous ovarian cancer (HGSOC), the abilities of tumor cells to resist cytotoxic treatment and relapse are largely driven by ovarian cancer stem cells (CSCs). CSCs are a population of cells within a tumor that maintain stem-like qualities and have the capacity to produce metastasis and drive drug resistance. Based on the complexity of CSC signaling and emerging evidence of differential isoform usage in development, we hypothesize that CSCs possess a patient-specific, heterogeneous landscape which exploits isoform diversity to sustain stemness, metastasis and drug resistance. Methods: RNA-seq was generated from 3 patient-derived HGSOC (PD-HGSOC) to investigate stemness and differentiation status comparing standard culture and CSCs. The data was analyzed at both gene- and isoform-levels to identify patient-specific CSC features and define mechanisms of cancer-related stemness and plasticity. Results: CSCs exhibited higher stemness characteristics and identified differentially expressed gene sets across PD-HGSOCs. We noted that each patient had a distinct subset of genes regulating stemness phenotypes which suggested multiple mechanisms of CSC development and maintenance. Additionally, a large proportion of gene-level expression changes were driven by the differential expression of a single predominant isoform. Importantly, our isoform-level analysis enabled the identification of differential isoform usage that would not be detected with gene level expression analysis. Conclusions: CSC phenotypes such as chemoresistance, metastasis and self-renewal are conserved across patients, but arise from largely patient-specific gene and isoform programs. This CSC heterogeneity is reflective of the heterogeneity seen in patients and should be further evaluated in deriving precision-medicine approaches for HGSOC.

Advanced-stage high grade serous ovarian cancer (HGSC) initially responds to platinum-based chemotherapy; however, most HGSC tumors recur and develop chemotherapy-resistance, making recurrent ovarian cancer (OC) a fatal disease. Ovarian cancer stem cells (OCSCs), a subpopulation of cells capable of surviving treatment and repopulating tumors, contribute to disease relapse, and understanding the mechanisms(s) responsible for OCSC survival is critical for developing strategies to overcome acquired resistance and prevent tumor recurrence. However, whether platinum-induced OCSC enrichment results from the selection of pre-existing OCSCs or chemotherapy-induced cellular plasticity, and the molecular mechanisms underlying these processes, remain poorly understood. Here, we demonstrated that cisplatin treatment not only enriched for OCSCs but promoted the conversion of ALDH- cells to ALDH+ cells, revealing chemotherapy-induced plasticity as a potential mechanism for OCSC expansion. This conversion was associated with nuclear receptor signaling pathways, vitamin D receptor signaling (VDR/RXR) and retinoic acid receptor signaling (RAR/RXR). Importantly, activation of VDR/RXR signaling with vitamin D reduced stemness phenotypes and the cisplatin induced conversion to ALDH+ cells. In addition, vitamin D combined with cisplatin decreased tumor volume in vivo compared to either treatment alone. In contrast, cisplatin treatment increased RAR/RXR signaling, supporting an associative role for ligand-dependent nuclear receptor signaling in OCSC plasticity. Together, these findings reveal that platinum chemotherapy can actively promote the acquisition of stem-like properties and identifies VDR/RXR signaling as a potential regulatory mechanism of OCSC plasticity. Targeting this pathway with vitamin D may provide a therapeutic strategy to target OCSCs and improve responses to platinum-based chemotherapy.

Soft tissue sarcomas (STS) are a heterogeneous group of mesenchymal malignancies with generally poor prognosis, raising a continued interest in novel therapeutic targets. The TAM-family receptor tyrosine kinase AXL has been proposed as a therapeutic target across several cancer types, including STS. Here we revisit the clinical relevance of AXL in STS by combining in silico analyses with functional and transcriptomic characterisation of two representative AXL inhibitors, dubermatinib and bemcentinib, in the HT-1080 and SK-LMS-1 STS-derived cell models. STS ranked among the tumour types with the highest median AXL mRNA expression across The Cancer Genome Atlas, yet AXL expression was not associated with patient survival. Both dubermatinib and bemcentinib reduced cell viability and induced apoptosis but, unexpectedly, shRNA-mediated AXL knockdown failed to reproduce the antiproliferative effect of either inhibitor and did not modify cellular sensitivity to drugs treatment. Transcriptomic profiling after AXL genetic knockdown showed weak correlation with drug-induced transcriptional changes, with the large majority of drug-regulated genes being AXL-independent and largely specific to each cell line. Our data indicate that although dubermatinib and bemcentinib show clear antitumour activity in STS models, this activity is largely independent from AXL inhibition, suggesting the rationale for AXL-directed therapy may be reconsidered.

Background Immune checkpoint blockade (ICB) has become the standard of treatment for metastatic melanoma (MM). However, patients with melanoma brain metastases (MBM) are often excluded from clinical trials. Here we analyse patients within the real-world OxCITE cohort receiving ICB treatment for metastatic melanoma, with a focus on MBM, aiming to discern outcomes, prognostic factors and peripheral biomarkers. Methods Patients eligible for ICB treatment were recruited prospectively. Demographic, clinical and radiological data were collected from electronic patient records. Plasma samples were collected prior to the first cycle of treatment for plasma proteomic analysis. Results 307 patients were included, 81 of whom had MBM on commencing ICB. No difference in overall survival between patients with and without brain metastases was noted on multivariable analysis (HR=1.1, 95% CI 0.73-1.6, p=0.68), whereas hepatic metastases were associated with increased risk of death (HR 1.7, 95% CI 1.2-2.4, p=0.0019). Within the MBM group, steroid treatment (HR=2.5, 95% CI 1.3-5.0, p=0.006) was associated with poor OS, whilst treatment with single agent ICB (HR=1.9, 95% CI 0.86-3.9, p=0.11), symptomatic first presentation of MBM (HR=1.5, 95% CI 0.76-2.8, p=0.25) and anti-seizure drug treatment (HR=1.74, 95% CI 0.89-3.4, p=0.10) were not. Amongst all patients carriage of a BRAF mutation was associated with increased risk of MBM (OR 2.49, 95% CI 1.4-4.4, p=0.0007), and increased propensity to new brain metastases on ICB treatment (OR 2.5, 95% CI 1.1-5.9, p=0.036). Analysis of blood and plasma samples demonstrated that patients with MBM have altered haematological profiles, with raised NLR and increased plasma glial fibrillary acidic protein levels, reinforcing the distinct systemic features of MBM. Conclusions In this real-world cohort of patients receiving ICB for metastatic melanoma, the presence of MBM did not associate with worse OS. Conversely, baseline corticosteroid use was adversely prognostic. Intriguingly, plasma GFAP was significantly elevated in patients with MBM and correlated with the burden of intracranial disease, highlighting a potential role for GFAP as a candidate biomarker for MBM in high-risk surveillance. Our observations indicate the adversely prognostic weight historically attached to M1d disease is no longer applicable in the ICB era.

Germ cell tumors (GCTs) are highly sensitized to cell death in response to DNA damaging agents, a property that underlies the success of current chemotherapeutic regimens. To address the molecular basis for this, known as apoptotic priming, we evaluated how different BCL2 family members modulate the heightened sensitivity of GCTs to therapy. Our analysis of human GCTs finds consistently high expression of the pro-survival factors MCL1 and BCL2L1 (BCLX) in a cohort of primary tumors and in their embryonic precursor cells, frequently accompanied by copy number gains of these loci and reciprocal losses of their pro-apoptotic interaction partners and inhibitors, PMAIP1 (NOXA) and BAD. We find that co-inhibition of MCL1 and BCLX using selective BH3 mimetics results in a potent synthetic lethality in multiple GCT embryonal carcinoma cell lines. When these cell lines were cultured with the DNA damaging agents cisplatin or etoposide, inhibition of MCL1 or BCLX potentiated their apoptotic effect in undifferentiated embryonal carcinoma cell lines, but not in retinoic acid-differentiated cells. The inhibition of MCL1 also heightened cisplatin sensitivity in p53-deficient or -mutant cell lines, which is associated with resistance to therapy. Employing an in ovo human xenograft model, we validate that the combination of cisplatin and MCL1 inhibition enhanced the therapeutic response by eliminating tumor cells. Our findings identify MCL1 and BCLX as critical factors to maintain GCT viability and as putative therapeutic targets to further augment GCT responsiveness to DNA damaging agents.

Introduction: Perioperative systemic therapy improves outcomes in gastroesophageal adenocarcinoma, but many patients do not receive postoperative treatment. We examined whether host characteristics and perioperative inflammatory and albumin changes provided information about adjuvant initiation beyond tumour pathology, and whether initiation was associated with survival and disease control. Method: This retrospective cohort included patients undergoing curative-intent resection for gastroesophageal adenocarcinoma at the McGill University Health Centre between 2006 and 2025. Sequential logistic models evaluated pathological characteristics, pre-treatment host variables and perioperative changes in CBC-derived neutrophil-to-lymphocyte ratio (cNLR) and albumin. Postoperative measurements preceded adjuvant initiation. Nested comparisons used matched complete cases. Day-90 landmark and time-varying Cox models assessed associations between adjuvant initiation and survival. Results: Among 243 patients, 78 (32.1%) did not initiate adjuvant therapy. Adding host variables improved apparent discrimination for initiation beyond pathology (AUC 0.672 to 0.763; P=0.002). Greater perioperative cNLR increase was associated with lower odds of initiation (adjusted OR 0.67 per unit increase in {Delta}log2; cNLR, 95% CI 0.47-0.95), whereas more favourable albumin change was associated with higher odds (OR 1.07 per g/L, 95% CI 1.01-1.13). Neither marker retained a clear independent association when modelled together. Adjuvant initiation by day 90 was associated with longer overall survival (adjusted HR 0.53, 95% CI 0.36-0.78) and disease-free survival (HR 0.57, 95% CI 0.39-0.84), with similar time-varying findings. Conclusion: Host inflammatory and albumin changes added information about adjuvant initiation beyond tumour pathology, and initiation was associated with longer survival. Prospective evaluation should determine whether host-directed perioperative strategies can improve postoperative treatment delivery.

Background: Adjuvant therapy decision in early-stage node-negative breast cancer remains one of the most challenging problems in oncology. Although most patients in this population achieve favorable outcomes with endocrine therapy alone, a subset remains at risk of relapse and may benefit from chemotherapy. Accurate identification of high-risk and low-risk patients is therefore essential to prevent both undertreatment and overtreatment. Methods: In this study, machine learning models were assessed using MSK-IMPACT (n=645) and METABRIC (n=503) cohorts comprising node-negative stage I-II breast cancer patients. Three experimental settings were evaluated: training on MSK-IMPACT and testing on METABRIC, the reverse direction, and five-fold cross-validation on the combined cohort. Sensitivity analysis and data harmonization were applied to identify and mitigate cohort-specific bias. Survival analysis, SHapley Additive exPlanations (SHAP) interpretability, and ablation analyses were performed to validate clinical relevance and characterize feature contributions. Results: The combined cohort model achieved an area under the receiver operating characteristic curve (AUC) of 0.788{+/-}0.028 across five-fold cross-validation, while bidirectional cross-cohort validation yielded AUC of 0.741 when testing on MSK-IMPACT and AUC of 0.714 when testing on METABRIC. Survival validation on METABRIC out-of-fold predictions from the combined cohort model showed hazard ratios of 3.01 (95\% CI: 2.28-3.98) for disease-free survival and 2.35 (95\% CI: 1.79-3.09) for overall survival, consistent across Luminal A, Luminal B, and Triple-Negative subtypes. Conclusion: Validated across two geographically independent cohorts, the proposed model enables cost-effective, gene expression-free identification of patients at high-risk of distant relapse and may facilitate adjuvant chemotherapy decision-making in early-stage node-negative breast cancer.

Background: Human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) shows higher prevalence of lymph node metastases than HPV-negative OPSCC. It remains unclear whether HPV-positive and HPV-negative OPSCC differ in occult metastasis risk, which is relevant to personalize elective nodal treatment volumes. Methods: We performed a retrospective analysis of 780 untreated OPSCC patients from four European centers. Patterns of lymph node level involvement (LNLs I, II, III, IV, V, VII) were assessed using a consensus diagnosis integrating imaging (CT, MRI, PET) and pathological findings from surgically treated patients. Occult metastases were assessed in 288 surgical patients with paired clinical and pathological information. Results: HPV-positive patients more frequently presented with ipsilateral LNL II involvement, particularly in early T-stage disease (80.6% [75.6-84.8] vs. 54.8% [47.2-62.2]). However, the probability of downstream involvement in LNLs III and IV conditioned on upstream LNL involvement was similar between HPV-positive and HPV-negative patients. Similarly, contralateral involvement conditioned on midline extension of the primary tumor was similar. The overall proportion of occult metastases, defined as clinically false-negative LNLs divided by pathologically positive LNLs, was lower in HPV-positive patients (24.7% [19.7-30.1] vs. 48.7% [39.7-57.8]). Conclusions: HPV-positive OPSCC showed higher prevalence of LNL involvement, especially in ipsilateral LNL II and early T-stage tumors. The data to directly compare occult metastasis risk has important limitations and does not allow definitive conclusions. However, the presented data suggests that higher prevalence likely does not translate into higher risk of occult metastases for the most common clinical diagnoses and therefore does not support larger elective nodal treatment volumes compared with HPV-negative tumors.

Abstract Background Liposarcoma is a rare cancer, comprising four major histological subtypes: well-differentiated, dedifferentiated, myxoid and pleomorphic liposarcoma. Therapeutic options remain limited for advanced disease, and additional biomarkers that may support biological characterization, diagnosis, or risk stratification are needed. Methods Bulk RNA sequencing (RNA-seq) was performed on paired tumour and adjacent non-tumour tissues from an analysable subset of 16 patients (22 tumour specimens) within a clinicopathological cohort of 21 patients. Differential gene expression analysis, principal component analysis, gene set enrichment (GSEA) analysis and single-sample GSEA (ssGSEA) were used to define subtype-specific transcriptional programs and imprinted-gene dysregulation. PEG10 expression was validated by RT-qPCR and RNA fluorescence in situ hybridization (FISH), and its cellular localization was explored by combined FISH and immunofluorescence for P53, vimentin, Ki67, and CD34. PEG10 expression in liposarcoma was further investigated in an external single-cell RNA-sequencing dataset of dedifferentiated liposarcoma. An exploratory survival analysis was performed in the pan-sarcoma TCGA-SARC cohort. Results Transcriptomic profiling identified distinct subtype-specific gene expression patterns and broad dysregulation of imprinted genes in liposarcoma compared with adjacent non-tumour tissue. Among all the imprinted genes, PEG10 showed a marked tumour-to-normal expression difference and good discriminatory performance between tumour and normal tissues in the discovery cohort (AUC=0.867). In the TCGA sarcoma cohort high PEG10 expression was associated with shorter overall survival. Immuno-FISH and single-cell analyses revealed that PEG10 was predominantly detected in tumour and proliferating cell populations. Importantly, PEG10 expression was higher in high-grade tumours. In bulk RNA-seq data, PEG10 expression correlated with hypoxia, extracellular matrix remodelling and invasion ssGSEA signatures. In the external single-cell RNA-seq dataset PEG10high tumours showed a reduced immune cell infiltration. Conclusions This study provides an integrated transcriptomic characterisation of liposarcoma and identifies PEG10 as a candidate tumour-associated biomarker linked to aggressive disease features. The diagnostic and prognostic value of PEG10 requires validation in larger, independent, subtype-balanced liposarcoma cohorts, and its potential therapeutic relevance requires direct functional investigation.

Background: This study compared functional and cognitive trajectories in older women treated for early breast cancer with matched women without cancer. Methods: Data were derived from two Dutch cohorts: the CLIMB study (women aged 75 years and older with operable breast cancer) and the ISCOPE study (community-dwelling women aged 75 years and older without cancer). Breast cancer patients were matched 1:2 to controls on age and baseline functional or cognitive status. Functional status was assessed using the Groningen Activity Restriction Scale (GARS), and cognitive function using the Mini-Mental State Examination (MMSE). Longitudinal changes over 12 months were analyzed using both unadjusted and confounder-adjusted linear mixed models. Results: 168 breast cancer patients and 336 matched breast cancer-free controls were included with a mean age of 80 years. Most breast cancer patients had stage 0-I or II disease and received surgery and/or radiotherapy; 48% received adjuvant endocrine therapy, chemotherapy was rare (<1%). At baseline, both cohorts were comparable in age and functional or cognitive status, although there was a higher comorbidity burden in the control cohort. No significant differences in functional or cognitive decline were observed between the cohorts over 12 months. Conclusions: In older women, early breast cancer and its treatment did not lead to accelerated decline in functional status or cognitive function within the first year compared to matched older women without cancer. These findings suggest that, for relatively fit older patients, breast cancer treatment may not accelerate functional decline in the short term.

Purpose: There is an unmet need in the treatment of triple-negative breast cancer (TNBC), as recurrence rates remain high; thus, novel treatment strategies are warranted to improve outcomes for patients. Smac mimetics (SMs) are small molecules that inhibit the inhibitors of apoptosis. In this study, we investigated the properties of the SM Xevinapant (AT406) as a radiosensitizer in TNBC. Methods: TNBC cell lines were treated with Xevinapant (AT406) in the presence or absence of ionizing RT and cell viability and apoptosis measured in vitro. Clonogenic assays were performed to confirm radiosensitization. We also assessed xevinapant radiosensitization in the presence of the Tumor Necrosis Factor (TNF) cytokine, which has been shown to enhance SM-induced apoptosis. Radiosensitization mechanisms were further validated by western blotting, flow cytometry and cell cycle analysis. Results: We show that Xevinapant increased cell death in a panel of irradiated TNBC cell lines. In clonogenic assays, Xevinapant sensitized MDA-MB-231 cells to RT-induced cell death, and this was significantly enhanced in the presence of TNF, with a dose-enhancing factor (DEF) of 1.57. We also show that Xevinapant radiosensitization is mediated by TNF-dependent apoptosis. Conclusions: Xevinapant is a radiosensitizer that enhances RT-induced cell death in TNBC cells, and TNF is central to this process through activation of apoptosis. These results are promising for combining RT with Xevinapant to improve local control in TNBC.

Circulating tumor cells (CTCs) are key drivers of distant metastasis, while platelets facilitate this process by protecting them from immune surveillance. However, the detection of CTCs exhibiting platelet markers and their communication with monocytes has not been thoroughly investigated. This study seeks to identify the intercellular communication of CTCs that have acquired platelet traits by integrating single-cell RNA-seq data of 377 CTCs and 2,634 white blood cells. Trajectory analysis identified a subpopulation of CTCs with enhanced platelet-related functions, including platelet aggregation and resistance to NK cell-mediated cytotoxicity, termed Platelet-Programmed CTCs. The Dampened Weighted Least Squares method was implemented to estimate the platelet-programmed tumor cell proportion in 1,102 bulk RNA-seq samples from primary breast cancer tumors. A strong inverse association was found between platelet-programmed tumor cell proportion and overall survival (Cox-PH p-value =0.00419, HR=6 per 10% increase in proportion, 95% CI:1.76-20.7). However, this association did not differ significantly between early- and late-stage patients. Cell-cell communication analyses and molecular docking revealed the CD40LG-ITGA5:ITGB1 pair as a potential immune checkpoint candidate for monocytes in cancer (Hex score=-656.83; TNF-TNFR reference complex=-515). However, further experimental and clinical validation is required to translate these findings. In conclusion, these findings deepen our understanding of the immune evasion mechanisms of CTCs by acquiring platelet characteristics. This immune checkpoint axis offers a novel avenue for further experimental validation and future intervention.

Background: Relapsed and refractory osteosarcoma (OS) remains a major therapeutic challenge, with fewer than 20% of patients surviving beyond 3 years. Increasing evidence indicates that MYC amplification/overexpression is associated with inferior survival. Small molecule inhibitors and immunotherapies have limited single-agent efficacy in pediatric solid tumors. Using syngeneic cell lines derived from p53-driven and MYC-hyperactivated genetically engineered mouse models (GEMMs) of OS, we tested cabozantinib, a multi-tyrosine kinase inhibitor with immunomodulatory properties, with TIGIT immune checkpoint blockade and investigated mechanisms underlying therapeutic response and resistance. Methods: In vitro cabozantinib sensitivity was established in GEMM-derived cell lines. Mice bearing tibial tumors were randomized to vehicle control, cabozantinib, anti-TIGIT antibody, or combination therapy, and tumor growth and survival assessed after a 3-week treatment period. Temporal RNA sequencing was performed at early (8-15 days) and late (18-24 days) time points to characterize transcriptomic changes associated with efficacy. Results: MYC-hyperactivated cell lines were more resistant to cabozantinib in vitro than p53-driven lines (mean IC50 5.51 vs 0.65 mciroM, p=0.0016). In p53-driven orthotopic models, combination therapy significantly decreased tumor growth and improved survival compared to solvent and cabozantinib alone, while in MYC-hyperactivated models cabozantinib-containing regimens delayed tumor progression relative to control or anti-TIGIT monotherapy, however the addition of anti-TIGIT did not significantly improve survival over cabozantinib alone. Temporal transcriptomics revealed upregulated anti-tumor immune-response pathways and decreased M2 macrophages only with combination treatment in the p53-driven model. In contrast, combination-treated MYC-hyperactivated models demonstrated increased TNF signaling and elevated Cxcl5 and Ccr2 expression, indicative of increased myeloid cell recruitment, and upregulation of extracellular matrix (ECM) remodeling pathways suggest a therapy-induced stress adapted state that propagates treatment resistance over time. Conclusion: New therapies are needed for patients with relapse or refractory OS. By targeting tumor-intrinsic resistance mechanisms and modulating the tumor microenvironment using cabozantinib and anti-TIGIT therapy, improved tumor control and survival was achieved in p53-driven orthotopic OS models. MYC-hyperactivated models were able to overcome therapeutic pressure and employ myeloid recruitment and ECM remodeling programs to achieve treatment resistance. Targeting of these programs should be considered in future studies investigating therapeutic strategies in relapsed and refractory OS.

Purpose Tarlatamab, a bispecific T-cell engager, has generated favorable response and survival outcomes in relapsed small cell lung cancer (SCLC). Factors influencing tarlatamab-associated treatment outcomes and toxicity have yet to be established. We performed a multivariate analysis to identify biomarkers associated with cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS) and integrated these variables into a novel risk stratification tool to identify patients at high risk of clinically significant toxicity. Patients and Methods Logistic and ordinal regression analyses evaluated the predictive value of variables contributing to the presence and severity, respectively, of CRS and ICANS in 115 patients with ES-SCLC receiving tarlatamab. Selected variables were then tuned using 5-fold cross-validation and incorporated into novel elastic net-based prediction models. Results Rates of observed CRS, ICANS, and dysgeusia were 46%, 28%, and 47%, respectively. ORR (overall response rate) and DCR (disease control rate) were 44% and 58.2%, while 6-month PFS (progression free survival) and OS (overall survival) rates were 30.4% and 54.9%, respectively. Excluding patients on tarlatamab <30 days, presence of dysgeusia was associated with a lower rate of disease progression (HR 0.44, p=0.00691) and death (HR 0.34, p=0.0145). The presence of, increased size and number of extracranial metastases as well as elevated baseline LDH were significantly associated with increased likelihood of CRS. Increased ECOG performance status, increased volume of brain metastases, development of CRS, and elevated baseline LDH were all associated with increased risk of developing ICANS. Our cross-validated risk model successfully predicted CRS grade [&ge;]2 and ICANS events with 90.9% and 75% sensitivity, respectively. Conclusions This exploratory analysis identified several predictive biomarkers of toxicity that successfully stratified low and high-risk populations as part of an internally validated novel risk scoring tool.

Background: Giant cell tumor of bone (GCTB) is an intermediate osteolytic neoplasm characterized by a high rate of local recurrence. The tumor comprises two main cell populations: neoplastic stromal cells and osteoclast-like giant cells. Current adjuvant therapies primarily target osteoclast-like giant cells but have limited activity against the neoplastic stromal cells that drive tumor growth and recurrence. Here, we sought to identify actionable vulnerabilities in GCTB stromal cells by profiling druggable receptor tyrosine kinases (RTKs) and associated signaling pathways and evaluating their pharmacological inhibition in patient-derived in vitro models. Methods: RTK activation and downstream signaling were assessed using phospho-protein arrays and western blotting in therapy-naive and denosumab-treated GCTB patient samples and in patient-derived GCTB cell lines, representing clinically relevant models of the neoplastic component. Tyrosine kinase inhibitors (TKIs) targeting activated pathways were evaluated in patient-derived GCTB cell lines cultured under both two-dimensional (2D) and three-dimensional (3D) conditions. Effects on cell viability, proliferation, cell cycle distribution, and cell death were assessed using MTT and XTT assays, flow cytometry, live-cell imaging, and confocal microscopy. Results: Several activated RTKs, including EGFR, IGF-IR, InsR, PDGFR, and PDGFR{beta}, together with downstream signaling proteins MEK1/2 and ERK1/2, were identified as potential therapeutic targets. Among the inhibitors tested, trametinib, a MEK1/2 inhibitor, and axitinib, a multi-target inhibitor of VEGFR1-3, PDGFR{beta}, and c-Kit, demonstrated the strongest antiproliferative and cytotoxic effects, markedly reducing cell viability and proliferation while promoting cell death in vitro. Importantly, trametinib showed selective activity against GCTB stromal cells compared with healthy controls, suggesting a potential therapeutic window. Conclusions: This study identifies trametinib and axitinib as promising therapeutic candidates for targeting the neoplastic component of GCTB. Our findings provide a rationale for further preclinical and clinical evaluation of RTK-directed therapies to complement current treatments and specifically target the neoplastic GCTB stromal cells underlying tumor persistence and recurrence.

Background: Clinicopathologic (SARCULATOR) and transcriptomic (CINSARC) models are established prognostication tools in soft tissue sarcoma, but neither directly represent the sequence context of tumor genomic alterations. Evo2 is a genomic foundation model trained to learn the grammar of DNA/RNA sequences. We tested whether Evo2-derived features from tumor short variants, fusions, and rearrangements improve survival prognostication beyond clinicopathologic and transcriptomic risk models. Methods: We analysed formalin-fixed, paraffin-embedded tumor material and clinical data from 102 patients with dedifferentiated liposarcoma (n = 25), high-grade leiomyosarcoma (n = 25), and undifferentiated pleomorphic sarcoma (n = 52). A separate TCGA-SARC cohort of comparable histologies (n = 129) served as external validation. Reconstructable alterations (short variants, fusions and rearrangements) were converted into sequence inputs, embedded with Evo2 and aggregated into patient-level genomic representations. Cox proportional hazards models incorporated genomic features alone (Evo2) or together with clinicopathologic (SARCULATOR) or transcriptomic (CINSARC) predictors across overall survival (OS), progression-free survival (PFS), disease-free survival (DFS), relapse-free survival (RFS), and metastasis-free survival (MFS). Discrimination was assessed using Harrell's concordance index (C-index). Results: Evo2 features were generated from 174 study-cohort sequences and 7298 TCGA-SARC sequences. In the study cohort, adding Evo2 to SARCULATOR increased the reported C-index for OS from 0.620 to 0.770, PFS from 0.625 to 0.755, DFS from 0.612 to 0.714, and RFS from 0.633 to 0.771. In TCGA-SARC, SARCULATOR plus Evo2 increased the OS C-index from 0.595 to 0.716 and the MFS C-index from 0.548 to 0.667. Also in TCGA-SARC, adding Evo2 to CINSARC increased the OS C-index from 0.476 to 0.653 and the MFS C-index from 0.553 to 0.650. These are descriptive point-estimate comparisons. Moreover, in TCGA-SARC Evo2 alone outperformed SARCULATOR alone and CINSARC alone, supporting independent prognostic information within altered sequence-context representations. Conclusions: Evo2-derived genomic representations improved clinicopathologic and transcriptomic prognostication across sarcoma cohorts and survival endpoints. These findings support genomic foundation models as an independent and complementary layer for sarcoma risk stratification through direct modeling of altered tumor sequence biology. Confirmation of model transportability, calibration and clinical utility is required before clinical application.

Introduction: Tumors are known to develop genomic heterogeneity over time, particularly in metastatic disease, raising concerns that a single-site biopsy may be insufficient to accurately predict response to medications. Methods: We used our 3D microtumor functional profiling platform that preserves key features of the native tumor microenvironment. We tested (i) six split samples from primary tumors and (ii) seven samples from primary tumors (ovarian, colon, and breast cancer) matched with their locoregional or distant metastases. Fresh tissue specimens were processed within 24 hours after surgery and treated with NCCN guideline-recommended chemo or targeted therapies at concentrations over four orders of magnitude. Cytotoxicity was evaluated after three days to generate dose response curves. The response correlations between the split sample or between the two matched sites were quantified using the concordance correlation coefficient ({rho}c) for the drug efficacy metrics. Results: We compared a total of 275 drug responses. The six split samples resulted in a strong correlation between the two tumor areas ({rho}c=0.95, p<0.001), supporting high assay reproducibility across distinct regions of the same tumor. Locoregional metastases were highly correlated with their primaries (ovarian to omentum {rho}c=0.97, p<0.001; ovarian to liver capsule {rho}c=0.93, p<0.001; colon to peritoneum {rho}c=0.91, p<0.001). A lesser correlation was observed with lymphogenic metastases (breast to axilla {rho}c=0.87, p<0.001), and the correlations of hematogenic metastases were even lower (colon to lung {rho}c=0.69 p<0.001; ovarian to soft tissue/colon {rho}c=0.58, p<0.001). No correlation was observed among specimens that were resistant to all tested medications. Conclusion: Tumor drug responses were highly preserved in locoregional metastases, whereas somewhat greater divergence was observed in lymphogenic or hematogenic metastases. Single-site functional profiling may remain informative for identifying treatment resistance and might reduce the risk of ineffective therapy selection in metastatic disease.

Background: Multidisciplinary tumor boards (MTBs) are a standard part of cancer care, yet India has no national measure of how many cancer patients are discussed at one. A national survey of hospitals in the National Cancer Registry Programme (NCRP), published in 2026, gives the first structured look at board presence and functioning. Objective: To describe how far hospital-level tumor board presence translates into all-case review, documentation and follow-up, and to define the data needed to measure patient-level coverage. Methods: Secondary analysis of published aggregate data: the ICMR-NCDIR survey of 229 hospitals in the NCRP hospital-based cancer registry (HBCR) network (October 2024), the HBCR 2021 report, national incidence estimates (ICMR-NCDIR 2022; GLOBOCAN 2024) and two published single-center MTB audits. We calculated proportions with Wilson 95% confidence intervals, non-response bounds across all 229 hospitals, and logical bounds for joint conditions. No individual-level data were used. Results: A total of 229 hospitals were invited and 172 responded (75.1%). Among the respondents, 137 (79.7%; 59.8% to 84.7% across all hospitals) reported a functional tumor board. Only 65 respondents (37.8%; 28.4% to 53.3%) reported boards that review all cases, 71 (41.3%) had a follow-up system, 50 (29.1%) used any electronic documentation and 7 (4.1%) always took part in cross-hospital reviews. The share of hospitals with both all-case review and a follow-up system could lie anywhere from 0% to 37.8% of respondents. Boards were reported more often in private (86.6%) than in public hospitals (72.5%). Two single-center audits reported about 800 case discussions (573 new patients) and 1,260 case discussions (about 917 patients) a year, but neither reported new registrations at the same hospital, so coverage could not be calculated. Conclusions: Tumor board presence is common in India, but evidence of all-case review, documentation and follow-up is much thinner, and the share of patients reviewed nationally is unknown. We propose six indicators that hospital-based registries could report to measure coverage directly.