Stomach Adenocarcinoma

This study developed and evaluated an optimized intramuscular patient-derived xenograft (PDX) platform for gastric cancer. The model achieved a high engraftment rate of 71.7%, significantly exceeding conventional methods. Researchers utilized whole exome sequencing to identify divergent driver mutations between fast- and slow-growing tumors. The findings suggest that PDX-guided chemotherapy selection is associated with improved progression-free survival, and that driver mutation profiles can serve as prognostic biomarkers.

This study investigated additional genetic alterations in MET-amplified gastric cancers (GCs), which are associated with poor prognosis and limited response to targeted therapies. Researchers found that MET amplification is frequently accompanied by co-amplifications of other oncogenes located on chromosome 7, such as BRAF, CDK6, and EGFR, in 54% of cases. These co-amplifications exhibit significant intra- and intertumoral heterogeneity. This complex heterogeneity may explain the diagnostic and therapeutic challenges, subclonal evolution, and the failure of targeted therapies in MET-amplified GCs.

This real-world study analyzed the genomic landscape of GNAQ and GNA11 mutations in 5,416 patients with metastatic solid tumors. It revealed that these mutations, while known in uveal melanoma, are also present in other cancers such as colorectal, melanoma, and gastric cancer. An immunogenic subgroup, characterized by non-hotspot mutations and high TMB or MSI, was identified and associated with potential benefit from immune checkpoint inhibitors. Canonical hotspot mutations, conversely, were predominant in TMB-low/MSS tumors. These findings highlight the importance of differentiating driver mutations from bystander mutations to guide therapeutic strategies.

This study investigated the role of the LMBR1L protein in gastric cancer, revealing its significant overexpression in tumor tissues. Patients with high LMBR1L levels exhibited reduced postoperative overall and disease-free survival rates. Multivariate analyses confirmed LMBR1L expression as an independent risk factor for gastric cancer patient prognosis. Furthermore, a nomogram model incorporating LMBR1L demonstrated good predictive value for postoperative survival. In vivo experiments also indicated that LMBR1L knockdown significantly inhibits tumor growth.

This study re-evaluates the clinicopathological and molecular features of nonampullary duodenal neoplasms with gastric phenotype, proposing a novel classification. Analyzing 105 lesions, researchers observed a predominance of low-grade tumors and frequent heterogeneity. Next-generation sequencing revealed recurrent mutations in GNAS, KRAS, and APC. MDM2 gene amplification was identified as a potential marker for histological progression in high-grade tumors. Despite morphological diversity, the prognosis was extremely favorable, with no metastases, supporting the reclassification as "gastric-type adenomas."