Background: The reprogramming of lipid metabolism, especially glycerolipid metabolism (GLM), plays a key role in cancer progression and response to therapy. However, the role and molecular characterization of GLM in pancreatic cancer (PC) remain unclear. Methods: A pan-cancer analysis of glycerolipid metabolism-related genes (GMRGs) was first conducted to assess copy-number variants, single-nucleotide variations, methylation, and mRNA expression. Subsequently, GLM in PC was characterized using lipidomics, single-cell RNA sequencing (scRNA-seq), and spatial transcriptomic analysis. A cluster analysis based on bulk RNA sequencing data from 930 PC samples identified GLM-associated subtypes, which were then analyzed for differences in prognosis, biological function, immune microenvironment, and drug sensitivity. To prioritize prognostically relevant GMRGs in PC, we employed a random forest (RF) algorithm to rank their importance across 930 PC samples. Finally, the key biomarker of PC was validated using PCR and immunohistochemistry. Results: Pan-cancer analysis identified molecular features of GMRGs in cancers, while scRNA-seq, spatial transcriptomics, and lipidomics highlighted GLM heterogeneity in PC. Two GLM-associated subtypes with significant prognostic, biofunctional, immune microenvironmental, and drug sensitivity differences were identified in 930 PC samples. Finally, ALDH2 was identified as a novel prognostic biomarker in PC and validated in a large number of datasets and clinical samples. Conclusions: This study highlights the crucial role of GLM in PC and defines a new PC subtype and prognostic biomarker. These findings establish a novel avenue for studying prognostic prediction and precision medicine in PC patients.

Background: Folate metabolism plays a pivotal role in tumor proliferation. However, the relationship between folate metabolism-related genes (FMGs) and the tumor immune microenvironment (TIME) in pancreatic cancer (PC) remains unclear. This study aimed to identify key FMGs and investigate whether FMGs are related to TIME in PC. Methods: Transcriptomic data from 732 PC patients were obtained from public databases, and 78 FMGs were gathered from the Molecular Signature Database (MSigDB). Pan-cancer analysis of genetic alterations in FMGs was performed. Patients with PC were stratified into two subtypes using non-negative matrix factorization (NMF). Clinical data and pathological sections from 150 PC patients were retrospectively collected as a validation cohort. The levels of dihydrofolate reductase (DHFR), FAP⁺ and α-SMA⁺ in cancer-associated fibroblasts (CAFs), CD8⁺ tumor-infiltrating lymphocytes (TILs), Foxp3⁺ TILs, CD206⁺ tumor-associated macrophages (TAMs) were analyzed using immunohistochemistry. Results: Copy number variation (CNV), single nucleotide variation (SNV), methylation, and risk levels of FMG in pan-cancer were confirmed. Compared to Cluster 1, Cluster 2 demonstrated significantly poorer overall survival (OS) (P<0.05), increased sensitivity to chemotherapy drugs, lower immune cell counts, and more immunosuppressive cells in TIME. DHFR was identified as the folate metabolism-driving gene in PC. DHFR was an independent predictor of poor prognosis (P=0.001). DHFR expression was strongly associated with CD206⁺ TAMs (P<0.001) and Foxp3⁺ T cells (P<0.05). Conclusions: FMG expression heterogeneity significantly impacts PC prognosis and TIME. DHFR, a central folate metabolism enzyme, demonstrates critical associations with TIME modulation and clinical outcomes in PC.

Background: Postoperative recurrence is the main barrier to long-term survival after curative resection of hepatocellular carcinoma (HCC). Whether recurrence timing, rather than recurrence itself, distinguishes lethal from non-lethal trajectories remains unclear. Methods: We analyzed 154 patients after curative HCC resection at a single centre. Preoperative circulating tumour cells (CTCs) were classified as epithelial, mixed, or mesenchymal (M-CTC); microvascular invasion (MVI) was graded M0-M2. We defined the dissemination axis (DA) as a composite of the preoperative M-CTC phenotype and postoperative pathological MVI grade. Because MVI is pathological, the complete DA can only be calculated after pathologic review, not before surgery. Early recurrence was defined as recurrence within 24 months. Overall survival (OS) and recurrence-free survival (RFS) were assessed with penalised Cox models, landmark and time-window analyses, competing-risk methods, and exploratory log-hazard mediation. Results: Of 154 patients, 142 (92.2%) developed recurrence: 118 with early recurrence, 24 with late recurrence, and 12 remained recurrence-free. During the observed follow-up period, no deaths occurred without prior recurrence (0/154); 80 of 83 deaths (96.4%) were preceded by early recurrence. Median OS was 18.5 months for early recurrence and was not reached for late or non-recurrence groups (observed median survival, 49.0 and 39.5 months respectively). Across DA strata, 24-month recurrence rates increased from 22.2% (low risk) to 95-98% (high risk), while median OS decreased from 47 to 12 months. High DA status independently predicted poorer RFS (HR 3.72; 95% CI 2.28-6.07) and OS (HR 3.25; 95% CI 1.69-6.25). The effect was concentrated in the first 24 months. Early recurrence accounted for 27.5% of the log-hazard attenuation (95% CI 15.5-44.9%), but this exploratory analysis cannot establish causal mediation. 24-month RFS status discriminated subsequent OS (time-dependent AUCs 0.732-0.862). Conclusion: In this exploratory single-centre retrospective cohort study, recurrence timing distinguished lethal from non-lethal outcomes. The DA, combining a preoperative CTC phenotype with the postoperative MVI grade, identified patients at high risk of 24-month early recurrence, supporting evaluation of risk-stratified surveillance and 24-month RFS as an early endpoint in perioperative HCC trials. Because no external validation was performed, these findings are hypothesis-generating and require independent validation before clinical use.

An abstract is unavailable. This article is available as a PDF only.