British Journal of Cancer

Abstract Background: High-grade serous ovarian cancer (HGSC) is characterized by extensive genomic heterogeneity and frequent alterations that promote replication stress (RS). Although RS has emerged as a promising therapeutic vulnerability, it remains unclear whether distinct RS-associated genomic alterations generate similar tumour states or drive unique biological programs and therapeutic dependencies. Methods: We developed and characterized a panel of syngeneic HGSC models representing recurrent RS-associated alterations, including overexpression of Ccne1, Brd4, Myc, Ndrg1, Pik3ca, and Brca1 heterozygosity, alongside previously established Pten/Nf1-deficient and Myc overexpressing models. Tumour fitness, transcriptomic programs, histopathology, extracellular matrix composition, immune organization, and therapeutic vulnerabilities were assessed using subcutaneous (s.c.) and intraperitoneal (i.p.) allografts, RNA sequencing (RNAseq), mass spectrometry (MS), cyclic-immunofluorescence (Cyc-IF), and preclinical therapeutic studies. Results: RS-associated genotypes exhibited marked differences in tumour fitness and generated distinct tumour ecosystem states despite sharing a common genetic background. Tumours harbouring BRCA1 heterozygosity displayed reduced tumour fitness, mesenchymal features, extracellular matrix remodelling, stromal expansion, and immune-excluded phenotypes. In contrast, tumours co-expressing Ccne1 and Brd4 exhibited the highest RS level together with strong activation of DNA damage response pathways and limited immune infiltration. Immune characterization identified immune-desert, immune-suppressed, and immune-excluded states across models, demonstrating substantial genotype-dependent immune heterogeneity. Elevated CD47 expression emerged as a defining feature of the Ccne1/Brd4 tumour state and was confirmed in human HGSC specimens with high CCNE1 and BRD4 protein expression. Therapeutic targeting of ATR and CD47 in intraperitoneal Ccne1/Brd4 allografts reduced tumour burden and induced histopathological responses compared with either monotherapy alone, supporting the translational relevance of this RS-high tumour state. Conclusions: Distinct RS-associated alterations do not converge on a common HGSC phenotype but instead generate diverse tumour ecosystem states with unique effects on tumour fitness, stromal remodelling, immune organization, and therapeutic vulnerabilities. These findings highlight the importance of considering the genetic origin of RS when developing therapeutic strategies and establish a framework for investigating genotype-specific vulnerabilities in HGSC.

Background: Although perioperative fluorouracil, leucovorin, oxaliplatin and docetaxel (FLOT) is the standard neoadjuvant regimen for resectable gastric and gastro-oesophageal junction adenocarcinoma, evidence describing treatment delivery in routine clinical practice remains limited, particularly regarding relative dose intensity (RDI) and treatment completion. Objectives: To evaluate real-world delivery of preoperative FLOT chemotherapy, including treatment completion, progression to surgery, RDI, toxicity and exploratory changes in estimated lean body mass (LBM). Methods: A retrospective single-centre service evaluation included consecutive patients receiving neoadjuvant FLOT during 2024. Outcomes included treatment completion, surgery, RDI, toxicity, pathological response and estimated LBM. Descriptive statistics were used. Results: Twelve patients were included (median age 68.6 years; 91.7% male). Eleven (91.6%) completed all four preoperative cycles and proceeded to surgery. Mean RDI was 76.7%. Pre-emptive dose capping was the predominant dose modification strategy, with only one reactive dose reduction. Two grade 3 adverse events occurred. Major pathological response (Mandard grade 1-2) was observed in 2/12 patients (16.7%). Mean estimated LBM declined from 54.3 to 53.4 kg. Greater LBM loss appeared to coincide with poorer clinical outcomes. Conclusions: High treatment completion and progression to surgery were achieved despite reduced RDI. These findings support prospective evaluation of strategies to optimise chemotherapy delivery while maintaining tolerability in routine clinical practice.

Background: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine neoplasms originating from chromaffin cells that express somatostatin receptors (SSTRs) and may therefore be susceptible to somatostatin analogue therapy. Despite this biological rationale, prospective evidence supporting the antiproliferative activity of somatostatin analogues in PPGL is limited. We conducted a multicenter phase 2 clinical trial to assess the efficacy and safety of lanreotide in patients with advanced or metastatic PPGL. [LAMPARA, NCT03946527] Methods: Patients with advanced or metastatic PPGL and evidence of recent disease progression received lanreotide depot/autogel 120 mg subcutaneously every 4 weeks. Treatment was planned for 52 weeks with an option to continue for an additional 52 weeks. Endpoints included overall survival (OS), progression-free survival (PFS), and response according to RECIST. Serum chromogranin A (CgA) was evaluated as an exploratory biomarker. A tumor growth rate analysis was planned to allow comparison with data from the CLARINET trial in gastroenteropancreatic NETs. Results: Eighteen patients (median age 42 years; range 28-77) across three centers participated; 78% carried SDHx mutations. Lanreotide was well tolerated with predominantly grade 1-2 adverse events and no treatment discontinuations due to toxicity. The most common treatment-emergent adverse events were diarrhea (67%), injection-site reaction (44%), constipation (39%), fatigue (39%), and abdominal pain (39%). Serious adverse events were reported in four patients and were assessed as not related or unlikely related to lanreotide. All 18 patients had at least one recorded post-baseline tumor assessment. Two partial responses were recorded during extended follow-up. At approximately 1 year, disease stabilization was observed in 11 of 13 patients (85%) with an available assessment, while two patients (15%) had progressive disease. Biomarker analysis showed substantial variability in serum CgA values. Tumor growth rate analysis revealed a median growth rate of 0.00124/day (tumor doubling time 559 days), comparable in order of magnitude to the rate of 0.00046/day observed in 83 lanreotide-treated patients in CLARINET, and consistent with a median PFS [≥]2 years. Conclusions: Lanreotide exhibits promising antiproliferative activity in PPGL, with a favorable safety profile and extended periods of disease stabilization. These findings support the consideration of SSAs as an option in managing SSTR-positive PPGLs, delaying more aggressive treatments until disease progression mandates escalation.

Background: Total neoadjuvant therapy (TNT) is increasingly used for treatment of locally advanced rectal cancer (LARC) to improve treatment compliance, oncological outcomes and opportunities for organ preservation. However, evidence describing its implementation and outcomes in low- and middle-income countries remains limited. This study evaluated the feasibility, treatment delivery, oncological outcomes and organ preservation outcomes of TNT in a real-world South African setting. Methods: This was a retrospective review of a prospective cohort of adults with histologically confirmed, non-metastatic LARC treated with TNT at the Wits Donald Gordon Medical Centre, Johannesburg, between March 2022 and January 2026. Treatment was individualised following multidisciplinary review and included induction and/or consolidation systemic chemotherapy with either long- or short-course radiotherapy. Following TNT, treatment response was assessed clinically, endoscopically and radiologically. Patients with a clinical complete response (cCR) were offered watch-and-wait (WW) surveillance, while those with an incomplete response were recommended for total mesorectal excision (TME). The primary outcome was organ preservation, assessed as TME-free survival. Secondary outcomes included tumour regrowth, disease-free survival (DFS), overall survival (OS), and local recurrence-free survival (LRFS) following TME. Results: Forty-six patients were included; median age was 63 years, 67.4% were male, 82.6% had T3-T4 tumours and 80.4% had node-positive disease. TNT was completed as planned in 95.7% of patients. Grade [≥]3 toxicity occurred in 19.5% during chemotherapy and 8.9% during radiotherapy. Twenty-one patients (45.7%) achieved a cCR and entered WW surveillance. TME-free survival was 46% (95% CI 31-60) at 1-year and 18% (95% CI 8-32) at 3-years. Three-year OS and DFS were 87% (95% CI 64-96) and 76% (95% CI 53-89), respectively. Among patients managed with WW, 3-year regrowth-free survival was 53% (95% CI 26-75). Three-year LRFS following TME was 94% (95% CI 68-99), and all patients undergoing TME or completed salvage surgery achieved an R0 resection. Conclusion: TNT was feasible and well tolerated in this real-world South African cohort, with high treatment completion and favourable medium-term oncological outcomes. Although almost half of patients initially achieved a cCR, declining TME-free and regrowth-free survival demonstrated that durable organ preservation was less frequent, highlighting the importance of structured surveillance and timely access to salvage surgery. These findings support the feasibility of delivering contemporary multimodal rectal cancer care in an appropriately resourced African setting.

Objectives Low grade serous ovarian cancer (LGSOC) is characterized by frequent TP53 wild type status and limited responsiveness to conventional chemotherapy. This study investigated the cytotoxic effects of oxaliplatin combined with 5-fluorouracil on patient derived LGSOC cells. Results Clinically relevant concentrations of oxaliplatin and 5-fluorouracil had minimal effects on LGSOC cell viability but markedly reduced cellular proliferation and clonogenic recovery. Combined treatment induced pronounced accumulation of cells in the G0/G1 phase of the cell cycle and increased expression of p53 and p21, accompanied by reduced pRB phosphorylation, consistent with activation of the p53-p21-pRb pathway. Oxaliplatin plus 5-fluorouracil also increased senescence-associated beta-galactosidase activity, cellular enlargement and flattening, and reactive oxygen species production, supporting a senescence-like phenotype. However, after drug withdrawal, treated cells progressively regained proliferative capacity, indicating that the senescence phenotype was transient rather than fully irreversible. Together, these findings show that oxaliplatin plus 5-fluorouracil primarily arrest rather than kill LGSOC cells and induces a transient senescence-like phenotype and G0/G1-phase arrest by activating the p53-p21-pRb pathway.

High-grade serous ovarian carcinoma (HGSOC) is the most common form of ovarian carcinoma and accounts for the majority of deaths from the disease, with fewer than half of patients surviving five years after diagnosis. Bulk transcriptomic profiling has identified molecular subtypes and gene-expression signatures associated with shorter or longer survival. However, because bulk profiling measures a composite of tumour and microenvironmental gene expression, the cellular origins of these signatures and their relationship to the tumour microenvironment remain unresolved. To address this, we applied Xenium spatial transcriptomics to treatment-naive HGSOC tumours from 122 patients using a custom 480-gene panel designed to measure tumour-intrinsic gene expression and distinguish immune and stromal cell populations in the surrounding microenvironment. Analysis of tumour-intrinsic gene expression identified 61 genes nominally associated with overall survival, from which Elastic-Net modelling prioritised five genes associated with longer survival and nine associated with shorter survival. Notably, 46 of the 61 associations did not reach the nominal significance threshold when expression was instead aggregated across all cells from the same patients, highlighting how whole-tissue expression can obscure tumour-cell-specific survival associations. Complementary analysis of tumour-proximal cell populations revealed that multiple immune populations were associated with longer survival, whereas two fibroblast populations were associated with shorter survival. Integrating these analyses revealed that survival-associated tumour-intrinsic gene expression was correlated with the abundance of neighbouring immune and stromal populations that were themselves associated with survival. Pairwise Cox regression demonstrated substantial overlap in the prognostic information captured by these features, while analysis of individual gene-cell combinations showed that survival associations differed according to the abundance of neighbouring populations. Consensus clustering further identified four patient groups with distinct combinations of tumour-intrinsic expression and microenvironmental composition, broadly separating patients with longer and shorter survival. Together, this cohort-scale spatial analysis identifies tumour-intrinsic and microenvironmental features associated with HGSOC survival and reveals how their correlated patterns and combined associations relate to patient outcome.

BackgroundNHS-Galleri did not reach its prespecified primary endpoint of a reduction in combined stage III and IV cases, but reported fewer stage IV cancers after annual multi-cancer early detection screening. We estimated the potential five-year life-years associated with the cancer-specific stage IV differences observed during the two incident screening rounds. MethodsWe used intervention and control stage IV counts for ten prespecified cancers reported in the NHS-Galleri ASCO 2026 presentation. For each cancer, the randomized-arm count difference was multiplied by the difference in five-year restricted mean survival time between stage III and IV, estimated from England stage-specific five-year net survival using a constant-hazard fit. Adverse cancer-specific differences remained in the model. Results were annualized across the two incident rounds and scaled per million people screened. Sampling intervals used an independent Poisson approximation for arm-specific counts. FindingsAcross the ten evaluable cancers, the intervention and control arms had 180 and 239 stage IV diagnoses during the incident rounds. The conditional projection was 66.3 potential life-years over five years in the trial intervention cohort, equivalent to 466 per million people screened annually (95% sampling interval 190-743). For a population of 10 million, the corresponding projection was 4,664 annually (1,896-7,432). Colorectal, lung, and esophageal cancers accounted for 79% of the net projection. Pancreatic, ovarian, and lymphoid cancers contributed negatively because their observed stage IV counts favored control. InterpretationIf the observed incident-round reduction in stage IV diagnoses represents true downstaging to stage III, it could produce meaningful population health gains. This conditional estimate is not evidence of mortality reduction. Longer follow-up remains necessary to distinguish benefit from chance, lead-time and length biases, overdiagnosis, and differences in tumor biology.

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.

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.

Therapeutic resistance remains a barrier to durable treatment of colorectal cancer (CRC), highlighting the need to identify vulnerabilities in resistant tumor cells. REV7 (MAD2L2) is a multifunctional genome-maintenance protein with established roles in REV3-dependent translesion synthesis (TLS) as well as mitotic progression, spindle organization, and chromosome segregation. Although perturbing REV7 dependent DNA damage tolerance has emerged as a strategy to overcome chemoresistance, whether pharmacologic targeting of REV7 exposes vulnerabilities to mitotic disruption remains poorly understood. Here, we investigated the REV7 targeting small molecule inhibitor C10, which disrupts the REV7 and REV3 interaction, and found that C10 sensitized HCT116 and HT29 CRC cells to the microtubule-disrupting agent colchicine, resulting in markedly reduced clonogenic survival. In contrast, C10 did not substantially enhance sensitivity to cisplatin. Genetic loss of REV7 similarly increased sensitivity to colchicine, independently supporting a REV7 dependent vulnerability to microtubule disruption. Combined C10 and colchicine treatment was associated with pronounced alterations in mitotic and post-mitotic nuclear morphology, including condensed/mitotic-like and multinucleated configurations, and increased micronucleus formation. In HT29 cells, combined treatment also increased the frequency of cells containing multiple gamma tubulin positive foci, consistent with disrupted centrosome-associated organization. Together, these findings support a model in which REV7 dependent functions contribute to cellular tolerance and recovery from microtubule mediated mitotic stress, whereas REV7 and REV3 disruption renders CRC cells vulnerable to mitotic perturbation. This study broadens the potential consequences of targeting REV7 beyond its canonical role in TLS and suggests that combining REV7 directed inhibition with mitotic perturbation warrants further investigation as a therapeutic strategy in CRC and potentially other cancers.

Background: Circulating proteins are promising biomarkers of colorectal cancer risk. Most studies combine colon and rectal cancer despite their biological differences. Objective: To identify proteins associated with colorectal, colon, and rectal cancer risk and triangulate findings using cross-cohort confirmation and Mendelian randomisation (MR). Design: We profiled 6,402 proteins, using the SomaScan 7K assay in a case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC; 658 colon and 319 rectal cancers). Cox models identified proteins associated with cancer risk at a false discovery rate <5%. Findings were confirmed in the Atherosclerosis Risk in Communities study (ARIC; SomaScan; 235 colon, 36 rectal) and UK Biobank (Olink Explore; 321 colon, 164 rectal). MR and genetic colocalisation evaluated potential causality. Results: We identified 36 proteins associated with colorectal cancer, 50 with colon cancer, and 2 with rectal cancer; 20 of the 36 were also associated with colon cancer and none with rectal cancer, and no protein was associated with both sites. Seven of the 40 colon cancer proteins available in ARIC were confirmed, including COMP, MIC-1/GDF15, TFF3, and THIK. Of these, MIC-1/GDF15 and TFF3 were also confirmed in UK Biobank. COMP was inversely associated with colon cancer risk observationally and in MR analyses. Conclusion: Colon and rectal cancers have different pre-diagnostic proteomic profiles, underlining the need for site-specific analyses. COMP, MIC-1/GDF15, and TFF3 were the most robustly supported biomarkers of colon cancer risk. Future work should prioritise experimental validation of these associations and use of repeated measures to define timing.

Deep learning (DL) applied to haematoxylin and eosin (H&E)-stained pathology images can predict microsatellite instability (MSI) in gastric cancer (GC). We evaluated its diagnostic accuracy and discriminative performance. PubMed, Embase, Cochrane Library and Web of Science were searched for studies applying DL to H&E images for MSI prediction in GC. The protocol was prospectively registered in PROSPERO (CRD420261503140). Risk of bias was assessed with QUADAS-2. Pooled sensitivity and specificity were estimated with a bivariate random-effects model, with subgroup analyses by validation strategy and data source; slide-level areas under the curve (AUCs) were pooled after logit transformation. Prespecified scenario analyses assessed robustness. Ten studies were included; seven independent datasets from six studies entered the primary synthesis. Pooled sensitivity, specificity and summary receiver operating characteristic AUC were 0.78 (95% CI 0.63-0.88), 0.85 (95% CI 0.77-0.90) and 0.89 (95% CI 0.86-0.91); nine studies contributed to the secondary AUC synthesis (pooled AUC 0.85, 95% CI 0.80-0.89). Hospital-derived cohorts showed numerically higher sensitivity (0.86) and diagnostic odds ratio (39.8) than TCGA-derived cohorts (0.71 and 11.5), but subgroup differences were limited by the small number of studies and substantial heterogeneity. DL models show good diagnostic accuracy for MSI prediction in GC, but clinical utility still requires confirmation in standardised multicentre, independent external and prospective studies.

Background: Patients with ER-positive/HER2-negative early breast cancer of low or intermediate grade are generally considered to have a favourable prognosis, yet a number will recur. This risk is poorly captured by standard clinicopathological factors. AI-based medical devices for whole slide image (WSI) analyses used for risk-stratification often predict on slide-level thereby overlooking spatial localisation of the biomarkers. We hypothesise that the spatial distribution of a previously reported AI-based marker provides independent prognostic value beyond its global score. Patients and Methods: This Swedish multicentre cohort study includes 6106 patients with primary invasive breast cancer: 3078 from the Stockholm region (training) and 3028 from Skane (independent test). Tile-level high-grade morphology scores were generated with ViT_DG, a vision-transformer adaptation of DeepGrade, and the presence of clusters of high-risk tiles localised at the invasive tumour front was defined as a binary biomarker. Primary analyses were pre-specified in the ER-positive/HER2-negative/lymph-node-negative and Grade 1-2 subgroup. Association with breast-cancer recurrence-free interval (BCRFI) and distant metastasis were assessed using multivariable Cox proportional hazards models (HR). Results: In the primary subgroup (n=1536 training; n=1403 test), tumour front clusters were present in 37% and 39% of patients. Cluster-positive status was associated with a 2.30-fold increased risk in the external test. Cluster-negative patients achieved a 10-year BCRFI of 95.3%, equivalent to Grade 1 patients and better than Grade 2 (92.4%), whereas cluster-positive patients (90.2%) did worse than the Grade 3 reference. The association was retained in patients classified as low-risk by ViT_DG (test set multivariable HR 2.86), identifying high-risk patients not captured by the global score. Conclusions: The absence of high-risk morphology clusters at the tumour front is an independent prognostic indicator, identifying a low-risk group independently of the global AI biomarker classification. More broadly, preserving the spatial distribution of AI-derived predictions enables prognostic stratification beyond slide-level aggregation.

Purpose: A minority of patients with bladder cancer derive lasting benefit from immunotherapy, and current biomarkers capture only part of the biology. We evaluated whether tumor-cell MHC class II defines an immune state associated with outcome across disease stages and after PD-1/PD-L1 blockade. Experimental Design: We localized differential MHC-II activity to malignant epithelial cells by single-nucleus and single-cell RNA sequencing and confirmed HLA-DR expression by immunohistochemistry in 122 specimens. Chromatin profiling and IFN-{gamma} stimulation of cell lines and primary tumors supported derivation of an 11-gene tumor-cell program. Associations were tested in 434 patients with non-muscle-invasive disease, 82 receiving neoadjuvant pembrolizumab, and 288 receiving atezolizumab for metastatic disease. Results: Tumor-cell MHC-II was present in approximately one third of bladder cancers, and malignant cells accounted for the differential signal between MHC-II-high and MHC-II-low tumors. The program was inducible by IFN-{gamma} through JAK/STAT signaling. Within luminal non-muscle-invasive disease, MHC-II-low status was associated with progression (HR 3.31, 95% CI 1.37 to 7.99). In PURE-01, the 11-gene program was associated with pathological complete response (52% versus 24%, p = 0.018) and recurrence-free survival (p = 0.0054), retaining an independent association in models including tumor mutational burden and PD-L1. In bladder-primary metastatic disease, program-high status was associated with overall survival in unadjusted analysis (HR 0.62, 95% CI 0.44 to 0.89); the association did not extend to upper tract tumors (interaction p = 0.0018). Conclusions: Tumor-cell MHC-II defines an inducible state associated with outcomes across bladder cancer stages and after checkpoint blockade, supporting prospective evaluation by RNA and immunohistochemistry.

Background: Severe hepatotoxicity has been reported when sotorasib follows immune checkpoint inhibitor (ICI) therapy, and fixed washout intervals have been proposed. We assessed prior ICI exposure and the ICI-to-sotorasib interval as separate risk factors. Materials and methods: We searched PubMed, Europe PMC, Embase, Web of Science, Scopus, CENTRAL, and meeting proceedings for comparative studies of grade 3 or higher hepatotoxicity after KRAS G12C inhibitors. Matched risk ratios (RRs) and unadjusted cohort data were synthesized separately, the latter with an exact conditional odds ratio (OR). Certainty was rated with GRADE. Results: Of 530 unique records screened, seven sources were included, all involving sotorasib. In the only matched analysis (meeting abstract, 386 patients per arm), prior ICI exposure was associated with higher risk (13.2% vs 4.4%, RR 3.00, 95% CI 1.76-5.10), whereas matched comparisons at 6 weeks (RR 1.11, 0.61-2.03) and 12 weeks (RR 1.08, 0.52-2.27) detected no difference but could not exclude important effects. All five unadjusted cohorts showed higher risk with shorter intervals, including 21/74 versus 8/75 patients in the earlier versus later interval quartiles of the CodeBreaK 200 trial, although effect sizes were heterogeneous (exact homogeneity P=0.006). Certainty was very low throughout. Conclusions: Prior ICI exposure was associated with higher risk of severe sotorasib-associated hepatotoxicity, with very low certainty. A shorter interval was associated with higher risk in unadjusted data only, and current evidence does not establish a mandatory washout period. Liver-test monitoring per the prescribing information applies to all patients, whereas additional surveillance after ICI exposure remains an untested precaution.

Background: Pancreatic ductal adenocarcinoma (PDAC) is projected to become the second leading cause of cancer-related mortality, with an increasing incidence and dismal 10% survival at 5 years despite best available care. PDAC is characterized by low tumour cellularity, recurrent driver mutation alterations, and substantial inter and intra-tumoural heterogeneity. The influence of individual genetic features such as sex and ancestry on tumour heterogeneity remains poorly understood. Methods: We assembled a cohort of PDAC across five datasets for a total of 7,527 tumours. Measures of genomic instability were assessed across sex and ancestry on a global level (SNV density and percent genome altered by copy number events), and at a gene level for recurrent events. KRAS variant frequencies, ploidy and mRNA abundance were also evaluated. Ancestry was assigned using ADMIXTURE from germline genotypes where available, and patient reported otherwise. Results: We observed ancestry-specific mutation patterns in global point mutation density, with higher SNV burden in African PDAC tumours and lower SNV burden in Asian PDAC tumours as compared to European tumours. We also identified an ancestry bias in the driver gene, GNAS, in which driver SNVs in GNAS was detected more frequently in those of Asian ancestry, and less frequently in those of African ancestry. No sex- or ancestry-associations were found for KRAS, but individual KRAS variants showed a trend towards ancestry-related variation. Conclusions: These findings demonstrate that ancestry contributes to the genomic heterogeneity of PDAC, shaping both global and gene-specific mutation patterns. This work underscores the importance of including diverse ancestries in PDAC molecular profiling efforts which may inform the development of tailored molecular diagnostics and targeted therapies.

Purpose: Metastatic pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine malignancies with limited systemic treatment options. Although inhibition of vascular endothelial growth factor (VEGF) signaling has demonstrated clinical benefit in metastatic PPGL, prospective data evaluating selective VEGF receptor inhibition remain limited. Axitinib is a potent and selective inhibitor of VEGFR-1, -2, and -3 with established activity in several solid tumors. We evaluated the efficacy and safety of axitinib in patients with progressive metastatic PPGL. Methods: Patients with progressive metastatic or unresectable PPGL were enrolled in a prospective, open-label, single-arm, phase II study (NCT03839498). Eligible patients had measurable disease according to RECIST version 1.1 and no prior treatment with a tyrosine kinase inhibitor. Axitinib was administered orally at an initial dose of 5 mg twice daily with protocol-defined dose modifications based on tolerability. The primary endpoints were objective response rate (ORR) and progression-free survival (PFS). Safety was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE). Results: Nineteen patients were enrolled, and 17 received study treatment. A confirmed partial response was achieved in 35.3% of treated patients. Median progression-free survival was 7.9 months (95% CI, 6.1-16.8 months), median duration of response was 7.4 months, median duration of treatment was 9.5 months, and median overall survival was 29 months. Hypertension, the most common treatment-related adverse event, occurring in 79% of patients, was effectively managed with antihypertensive therapy and dose modification. Other common treatment-related adverse events included fatigue, diarrhea, oral mucositis, and palmar-plantar erythrodysesthesia. No patient permanently discontinued treatment because of treatment-related toxicity. Conclusions: In patients with progressive metastatic PPGL, single-agent axitinib demonstrated clinically meaningful antitumor activity with a manageable safety profile. The observed efficacy compares favorably with sunitinib in this rare disease. The ability to maintain treatment despite predictable VEGF-associated toxicities suggests that axitinib represents a viable therapeutic option for patients with metastatic PPGL.

ABSTRACT BACKGROUND: Next-generation sequencing (NGS) and the development of targeted therapies have revolutionized cancer treatment. Molecular Tumour Boards (MTB) serve as collaborative platforms to integrate individual clinical and molecular information to make recommendations for personalized treatment. METHOD: This is a single-center, retrospective cohort study of patients presented at the Jewish General Hospital (JGH) MTB between July 2018 and Dec 2022. Clinical, molecular/pathologic data, MTB recommendations, and treatment details were collected. Treatment response was determined by radiological evaluation and physician clinical assessment. Fishers exact test and Log-rank tests were used to assess differences between groups. RESULTS: A total of 328 patients were presented to the MTB, including 23 with repeat presentations, resulting in 355 case reviews. Tumour-agnostic biomarkers were detected in 18.9% of cases, most commonly high tumour mutational burden (TMB, 9.5%) and HER2 amplification (4.3%). The most frequent actionable mutations were PIK3CA (19.8%) and PTEN (13.1%), often leading to recommendations for mTOR inhibitor therapy (26.0%). Overall, therapeutic recommendations were issued in 84.5% (300/355) of cases, and implemented in 43.3% (130/300). Patients who received MTB-recommended therapies achieved significantly higher objective response rates (ORR) (14.2% vs. 4.2%; P = 0.047), longer real-world progression-free survival (rwPFS) (5.6 vs. 3.5 months; HR 0.57; 95% CI 0.390 - 0.828; P = 0.003), and improved median overall survival (OS) (12.8 vs. 5.2 months; HR 0.60, 95% CI 0.452 - 0.793; P < 0.001) compared with those treated without MTB guidance. CONCLUSION: MTB is effective in identifying biomarker-matched therapeutic recommendations for advanced malignancies where limited standard-of-care treatment option is available.

Background: Cancer-associated fibroblasts (CAFs) contribute to systemic therapy resistance in muscle-invasive bladder cancer (MIBC), but their functional heterogeneity and relevance to curative bladder-preserving radiotherapy, are poorly understood. Methods: Transcriptomic analysis was performed on 279 tumours from BC2001, a phase 3 radiotherapy clinical trial. To study CAF heterogeneity, we integrated bulk RNA-seq, single-cell spatial analysis of multiplex immunofluorescence images and quantification of extracellular matrix (ECM) features in 155 MIBC biopsies. The functional heterogeneity of distinct CAF populations was evaluated by single-nuclear RNA-seq. Spatial interactions between CAF populations and CD8+ T-cells was assessed and the relevance of lymphocytes to radiation responses was evaluated in a CAF-enriched murine bladder cancer model (BBN963). Results: BC2001 patients with CAF-enriched tumours had worse overall survival (HR=1.671, 95% CI 1.221-2.287, Log-rank p=0.0012). CAF abundance and antigen expression was highly heterogenous. Podoplanin (PDPN) was expressed on the majority of CAFs and was associated with inflammatory pathways. Enrichment of CAF gene signatures was associated with a significant increase in CAFs expressing fibroblast activation protein (FAP) (p=0.004) and dense ECM features (p=0.0004). Fifty-three percent of tumours exhibited stromal CD8+ T-cell exclusion with significant enrichment in FAP-dominant neighbourhoods (p<0.001). In vivo, lymphocytes were critical for radiation-induced tumour control, indicating that immune cold or excluded tumours may have limited radiotherapy responses. Conclusion: In MIBC, CAFs are associated with poor radiotherapy outcomes. Multiple mechanisms are deployed by functionally-heterogeneous CAFs, including promotion of chronic inflammation by PDPN+ CAFs and ECM remodelling by FAP+ CAFs which impact CD8+ T-cell distribution and radiation responses.

Background: Prostate cancer (PCa) is the most common urological malignancy globally and remains a major cause of cancer mortality among men. In Hong Kong, a comprehensive evaluation of disease burden, real-world treatment patterns, and outcomes across clinically relevant PCa subgroups is essential for identifying unmet needs and optimising care delivery. Objectives: This study aims to characterise the burden of PCa and patterns of care in Hong Kong by (1) estimating annual patient load (2) describing treatment patterns, and (3) evaluating real-world outcomes among patients receiving systemic therapy (chemotherapy or novel hormonal agents [NHA]) and novel agents (immunotherapy, poly ADP-ribose polymerase [PARP] inhibitors, radiation therapy). Methods: We conducted a population-based retrospective cohort study using electronic medical records from the Hong Kong Hospital Authority (HA). The cohort included patients diagnosed with PCa between January 1, 2012 and December 31, 2024. Subgroup analyses included patients with metastatic hormone-sensitive prostate cancer (mHSPC) and metastatic castration-resistant prostate cancer (mCRPC) and were further stratified by the treatment received. Descriptive analyses summarised annual patient load and treatment patterns over 2018 to 2022. We evaluated treatment outcomes from 2012 to 2024, including overall survival, progression-free survival, number of hospitalisations, and main adverse events. Results: From 2018 to 2022, prevalence increased for prostate cancer (12,014 to15,610), mHSPC (1,188 to 1,779), and mCRPC (167 to 290), while annual mCRPC incidence rose from 125 to 274. There was an increasing number of prevalent and new users of the investigated novel treatment, including first-/second-/third-line therapy for mCRPC. Compared with patients treated with NHAs, chemotherapy showed a numerically higher rate of hospitalisations, bone treatment initiation and higher hematologic toxicity. Conclusions: This population-based retrospective study provides Hong Kong-specific evidence on PCa burden, real-world management, and outcomes across key subgroups, thereby supporting policy planning, formulary evaluation, and targeted strategies to address unmet clinical needs. Funding: This work was supported by a grant from Novartis.