Integrated Spatial and Bulk Untargeted Metabolomics Characterize Location- and Histology-Associated Metabolic Heterogeneity in Colorectal Cancer.

Colorectal cancer (CRC) exhibits profound molecular heterogeneity according to primary tumor location, but spatially resolved assessment is limited by interindividual variability. Here, to minimize interindividual genetic confounding, we performed an exploratory single-case spatial metabolomics study (MALDI-MSI) on a rare case of synchronous bilateral tumors from one patient. This was complemented by untargeted metabolomics (UHPLC-HRMS/MS) on tumor and matched normal tissues from a cohort of 30 CRC patients with different anatomical sites and histologies. As an observational finding in this single case, the left-sided colon cancer (LCC) showed distinct metabolite distribution features from the tumor core to the invasive margin, whereas in right-sided colon cancer (RCC), metabolic differences were more closely associated with a histological subtype. UHPLC-HRMS/MS showed that, among tubular adenocarcinomas, LCC exhibited enrichments in ether lipid and phosphatidylcholine metabolism, whereas RCC preferred nucleotide and fatty acid metabolism. Furthermore, right-sided mucinous adenocarcinomas displayed unique sphingolipid alterations, consistent with a possible desaturase-associated shift from apoptosis-promoting pathways toward structural functions compared with the tubular subtype. Collectively, these findings underscore the potential influence of primary tumor location and histology on a microenvironmental metabolic architecture, offering exploratory insights for future hypothesis testing on location- and histology-dependent tumor adaptation.