Clin Transl Oncol. 2026 Jan 21. doi: 10.1007/s12094-025-04214-3. Online ahead of print.

ABSTRACT

Pancreatic cancer (PC), predominantly pancreatic ductal adenocarcinoma, remains one of the most lethal malignancies, largely due to late diagnosis and intrinsic resistance to conventional therapies. In recent years, mismatch repair deficiency (dMMR) and microsatellite instability-high (MSI-H) have emerged as clinically actionable biomarkers in a small but distinct subset of PC, accounting for approximately 1-2% of cases. These tumors display unique molecular characteristics, including a high prevalence of wild-type KRAS and TP53, elevated tumor mutational burden, and recurrent kinase fusions, which together confer enhanced immunogenicity and increased sensitivity to immune checkpoint inhibitors (ICIs). In addition to their therapeutic relevance, dMMR/MSI-H status has important diagnostic implications for the identification of Lynch syndrome-associated pancreatic cancers, informing genetic counseling and familial risk assessment. This review summarizes current understanding of the molecular basis of mismatch repair deficiency and microsatellite instability in PC, evaluates available diagnostic approaches such as immunohistochemistry, polymerase chain reaction, and next-generation sequencing, and discusses the prognostic and predictive significance of dMMR/MSI-H status. Emerging clinical evidence supporting the use of ICIs in selected patients across neoadjuvant, adjuvant, and advanced disease settings is also reviewed, along with challenges related to assay discordance, tumor heterogeneity, and immunotherapy resistance. Finally, future directions are highlighted, emphasizing the need for standardized testing algorithms, integration of multi-omics and spatial profiling technologies, and prospective clinical studies to optimize precision treatment strategies for this rare but clinically meaningful subtype of pancreatic cancer.

PMID:41563663 | DOI:10.1007/s12094-025-04214-3

Mol Biomed. 2025 Mar 20;6(1):18. doi: 10.1186/s43556-025-00257-8.

ABSTRACT

Cancer ranks among the most lethal diseases worldwide. Tissue biopsy is currently the primary method for the diagnosis and biological analysis of various solid tumors. However, this method has some disadvantages related to insufficient tissue specimen collection and intratumoral heterogeneity. Liquid biopsy is a noninvasive approach for identifying cancer-related biomarkers in peripheral blood, which allows for repetitive sampling across multiple time points. In the field of liquid biopsy, representative biomarkers include circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and exosomes. Many studies have evaluated the prognostic and predictive roles of CTCs and ctDNA in various solid tumors. Although these studies have limitations, the results of most studies appear to consistently demonstrate the correlations of high CTC counts and ctDNA mutations with lower survival rates in cancer patients. Similarly, a reduction in CTC counts throughout therapy may be a potential prognostic indicator related to treatment response in advanced cancer patients. Moreover, the biochemical characteristics of CTCs and ctDNA can provide information about tumor biology as well as resistance mechanisms against targeted therapy. This review discusses the current clinical applications of liquid biopsy in cancer patients, emphasizing its possible utility in outcome prediction and treatment decision-making.

PMID:40108089 | PMC:PMC11923355 | DOI:10.1186/s43556-025-00257-8