Predictors of gastrointestinal malignant tumors in fecal occult blood positive individuals prior to percutaneous coronary intervention: a Nomogram-based approach

Abstract Objectives Fecal occult blood (FeOB) is widely used for screening gastrointestinal diseases, but its predictive value for gastrointestinal malignant tumor (GI MT) in patients receiving antiplatelet medication before percutaneous coronary intervention (PCI) remains unclear. Methods This retrospective cohort study included 1986 patients with an initial positive FeOB test prior to PCI from January 2015 to April 2020. All patients underwent repeated FeOB testing. If the second test was negative, the patient was classified into the FeOB-negative group. If the second test was positive, a third FeOB test was performed. Patients were then categorized into: 1) FeOB-negative group (negative result on the second or third test), and 2) FeOB-positive group (positive results on all three consecutive tests). According to endoscopic results, the patients were divided into GI MT and non-GI MT groups. Multivariable logistic regression was used to identify independent predictors, and a nomogram was constructed to estimate individualized risk. Results Among 1986 patients with an initial FeOB positive, 427 (21.5 %) patients received endoscopy. Endoscopy identified 127 patients with GI MT. The prevalence of GI MT was significantly higher in patients with three consecutive positive FeOB results compared with those whose results converted to negative (39.9 % vs. 14.2 %, p<0.001). Multivariable analysis identified age (OR 1.05, 95 % CI 1.02–1.08, p<0.001) and persistent FeOB positivity (OR 3.97, 95 % CI 2.32–6.80, p<0.001) as independent predictors. A nomogram incorporating these variables demonstrated acceptable discrimination and clinical utility. Conclusions For patients with an initial positive FeOB test before PCI, advanced age and persistent FeOB positivity are associated with increased risk of GI MT. A risk-based approach using repeated FeOB testing and individualized risk estimation may support decisions regarding endoscopic evaluation.