BACKGROUND: Cancer antigen 125 (CA125) is widely recognized as a useful biomarker for surveillance of patients with ovarian and other cancers. Prior GWAS studies have identified variants that influence CA125 levels. We evaluated the utility of stratifying CA125 levels by such variants and evaluated diagnostic performance in control subjects and patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: We measured CA125 levels in 807 control subjects and 450 patients with PDAC and genotyped ten variants involving four genes (GAL3ST2, MSLN, D2HGDH, and MUC16). We compared CA125 levels in controls by variant and generated variant-defined CA125 cutoffs, then classified cases and controls into functional groups based on their variant profile. We used this variant classification to evaluate the diagnostic performance of CA125 in patients with PDAC. RESULTS: Six variants associated with CA125 levels were used to group controls into one of four groups. Mean CA125 levels in the highest variant group were ~4-fold higher than in the lowest group. African-Americans were more likely to have a variant group associated with low CA125 levels. After setting diagnostic cutoffs by variant group, the diagnostic sensitivity of CA125 for PDAC was 20.2% at 98% specificity (AUC; 0.702), not significantly different from a uniform CA125 diagnostic cut-off (AUC; 0.700). CONCLUSIONS: Gene variants can be used to generate personalized CA125 reference ranges. This approach did not significantly improve CA125's diagnostic performance for pancreatic cancer, but it merits evaluation in other diagnostic settings, such as detecting ovarian cancer. IMPACT: Gene variants can be used to personalize CA125 levels.

In pancreatic ductal adenocarcinoma (PDAC), venous invasion (VI) is a critical step in metastasis and is associated with poor survival. However, little is known about the molecular features of VI. To investigate, we performed spatial transcriptomic analysis of 95 human PDAC tissue samples from eight treatment-naïve patients. Our analysis revealed that, compared with PDAC in stroma, PDAC with VI demonstrated up-regulation of genes associated with epithelial differentiation, classical subtype, and benign exocrine function. Conversely, PDAC with VI demonstrated down-regulation of genes associated with mesenchymal differentiation, basal-like subtype, and disease aggression. Additionally, we uncovered characteristics of VI morphology that correlated with these molecular features. VI-intraepithelial neoplasia-like foci had preserved venous architecture and had a classical, epithelial molecular phenotype, whereas VI-destructive foci had destroyed venous architecture and had a more basal-like, mesenchymal phenotype. We contextualized our findings using public RNA-seq data and observed that metastatic PDAC had greater similarity to PDAC in stroma than to PDAC with VI, whereas circulating tumor cells showed no preferential association. We confirmed our findings by spatial proteomic analysis of VI in an independent cohort of 19 treatment-naïve patients with PDAC. Overall, our work provides a reference atlas of spatial transcriptomics and proteomics of VI in PDAC and reveals unexpected increases in molecular features associated with better patient outcomes.

Pancreatic ductal adenocarcinoma (PDAC) poses a significant challenge due to late-stage diagnoses. To improve patient outcomes, early intervention in precursor lesions such as intraductal papillary mucinous neoplasm (IPMN) is crucial. However, early intervention must be balanced against overtreatment of low-risk lesions that are unlikely to progress, underscoring the need to better understand molecular alterations in neoplastic cells and changes in the tumor microenvironment (TME) that drive the progression of IPMNs. In this study, we characterized alterations in the TME of IPMNs as they progressed to high-grade dysplasia, using immunohistochemistry to quantify immune cell density and activation status in more than 100 well-characterized human IPMN samples. Analyses revealed progression to a more immunosuppressive TME in high-grade IPMN compared with low-grade IPMN, characterized by elevated expression of immune checkpoint molecules (PD-L1, TIM3, VISTA), increased density of macrophages, and decreased density of cytotoxic T cells. Intriguingly, the alterations in macrophages were limited to focal regions of high-grade dysplasia, while T-cell alterations affected the entire IPMN. Additionally, elevated VISTA expression was associated with poorer clinical outcome after IPMN resection in an independent cohort. These findings provide important insights into the interplay between the immune microenvironment and IPMN progression, highlighting potential targets to modify the TME for cancer interception. © 2025 The Pathological Society of Great Britain and Ireland.

Abstract Objectives Treating pancreatic ductal adenocarcinoma (PDAC) is a major clinical challenge, owing to its poor prognosis. Understanding the underlying molecular interactions may be crucial in determining PDAC intractability. We elucidated the combinatory role of SMAD family member 4 (SMAD4) and Runt-related transcription factor 3 (RUNX3) in PDAC. Methods Formalin-fixed and paraffin-embedded tissues were obtained from 101 patients who underwent surgical resection of PDAC. SMAD4 and RUNX3 expression in the tissues was evaluated using immunohistochemistry. SMAD4 and KRAS mutations were evaluated using Sanger sequencing. SMAD4 copy number variations were evaluated using quantitative real-time PCR. These molecular characteristics were compared with clinicopathological features of patients. Results Retained SMAD4 expression in PDAC tissues was associated with higher tumor, node, metastasis (TNM) stage, and metastatic recurrence. Defective RUNX3 expression was associated with higher TNM stages. Further analysis to determine significance of retained SMAD4 indicated that all these cases had defective RUNX3 expression; therefore, the combined expression status of retained SMAD4 and defective RUNX3 expression in tissues was determined to be associated with higher TNM stage and metastatic recurrence than defective SMAD4 expression with defective or retained RUNX3 expression. Survival analysis showed that patients with tumors with retained SMAD4 and defective RUNX3 expression had relatively worse overall survival (OS) rates. KRAS mutations were not associated with SMAD4/RUNX3 expression or OS. Conclusions Despite inherent limitations of this retrospective study and small sample size, our findings highlight the potential combined role of SMAD4 and RUNX3 in node metastasis and metastatic recurrence in patients with resected pancreatic cancer.

Objective: This study aimed to clarify the molecular mechanism of remnant pancreatic cancer (PC) development after primary PC resection. Summary Background Data: Molecular mechanisms of the development of remnant PCs following primary PC resection are largely unknown. Methods: Forty-three patients undergoing remnant PC resection after primary PC resection between 2001 and 2017 at 26 institutes were retrospectively analyzed. Clinicopathological features and molecular alterations detected by targeted amplicon sequencing of 36 PC-associated genes were evaluated. Results: These patients showed significantly lower body mass indices and higher hemoglobin A1c values at remnant PC resection than at primary PC resection. A comparison of the molecular features between primary and remnant PCs indicated that remnant PCs were likely to develop via three different molecular pathways: successional, showing identical and accumulated alterations (n=14); phylogenic, showing identical and distinct alterations (n=26); and distinct, showing independent distinctive alterations (n=3). The similarity of gene alterations was associated with time to the remnant PC development (r=－0.384, P=0.0173). Phylogenic pathways were significantly associated with the intraductal spread of carcinoma (P=0.007). Patient survival did not differ significantly depending on these molecular pathways. Conclusion: Molecular profiling uncovered three pathways for the development of remnant PCs, namely, successional, phylogenic, and distinct pathways. The vast majority of remnant PCs are likely to be molecularly associated with primary PCs either in the successional or phylogenic way. This information could impact the design of a strategy for monitoring and treating remnant PCs.