Apo10 and TKTL1 as novel liquid biopsy biomarkers for early detection of gastrointestinal malignancies

Abstract Early detection of gastrointestinal malignancies (GIMs) remains suboptimal, particularly at potentially curable stages. We evaluated the diagnostic performance of epitope detection in monocytes (EDIM)‐based biomarkers Apo10, TKTL1, and their composite index APT for early‐stage GIM screening. A total of 333 patients with histologically confirmed esophageal cancer, gastric cancer, and colorectal cancer, and 241 age‐ and sex‐matched healthy controls were enrolled between March 2021 and April 2025 at Sun Yat‐sen University Cancer Center. Peripheral blood Apo10 and TKTL1 levels were quantified by the EDIM assay, and APT was calculated accordingly. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic efficacy of each biomarker, which was compared with conventional serum markers (CEA, CA19‐9, and CA72‐4). Subgroup analyses were performed by tumor type, stage, pathological type, and differentiation grade. Compared with healthy controls, GIM patients showed significantly higher levels of Apo10 (140.00 vs. 133.00), TKTL1 (119.00 vs. 115.00), and APT (259.00 vs. 248.00; all p < .001). Among these markers, APT exhibited the best diagnostic performance (area under the curve [AUC] = 0.901; sensitivity, 78.7%; specificity, 85.9%), followed by Apo10 (AUC = 0.876; sensitivity, 83.5%; specificity, 80.1%), TKTL1 (AUC = 0.793; sensitivity, 74.5%; specificity, 68.0%). In contrast, the conventional biomarkers have poor diagnostic performances, for example, CA19‐9 (AUC = 0.524; sensitivity, 51.8%; specificity, 55.6%). Diagnostic robustness was maintained across all subgroups. Apo10, TKTL1, and APT demonstrated promising diagnostic performance in early‐stage GIM and these biomarkers will offer a potential practical, minimally invasive tool for early cancer detection.