Clinical Application of Serum Gastrin-17 and Blood Lipid Indicators in the Screening of Colorectal Polyps

<title>Abstract</title> <p>Objective To assess whether combining serum gastrin-17 (G-17), blood lipid indices, and selected tumor markers improves screening performance for colorectal polyps. Methods This retrospective study enrolled 96 patients diagnosed with colorectal polyps between November 2021 and August 2022 (observation group). Diagnoses were confirmed by colonoscopy with histopathology from endoscopic or surgical resection, and gastroscopy was performed to evaluate the gastric mucosa. During the same period, 96 individuals with normal gastric and colorectal mucosa confirmed by gastroscopy and colonoscopy were included as controls. Demographic and clinical characteristics and serological indicators were collected. Screening performance was evaluated using receiver operating characteristic (ROC) analysis. Results Sex distribution and smoking history differed significantly between groups (both P &lt; 0.05). Among the serological variables, G-17 and triglycerides (TG) were higher in the observation group than in controls (both P &lt; 0.05). For screening colorectal polyps, the area under the ROC curve (AUC) was 0.60 for G-17, 0.62 for TG, and 0.69 for the combined G-17 + TG model. The optimal cutoff was 0.81 for G-17 (sensitivity 100%, specificity 16.8%) and 1.26 for TG (sensitivity 55.8%, specificity 68.4%). For the combined model, the cutoff was 0.53, yielding a sensitivity of 65.3% and specificity of 69.5%. Within the observation group, carbohydrate antigen 19 − 9 (CA19-9) and carbohydrate antigen 50 (CA50) were higher in patients with adenomatous polyps than in those with non-adenomatous polyps (P &lt; 0.05). Serological indicators did not differ significantly across polyp locations (right colon, left colon, rectum; P &gt; 0.05). Conclusion Combined detection of G-17 and TG improves screening performance for colorectal polyps compared with either marker alone. CA19-9 and CA50 may help differentiate adenomatous from non-adenomatous polyps. In contrast, these serum markers show limited value for predicting polyp location.</p>