MPO and cancer: From 19,920 initial examinees meeting inclusion criteria, 15,180 were retained after protocol-driven exclusions: missing H. pylori test (n = 2590), missing MPO data (n = 10), incomplete laboratory data (n = 1808), age < 18 years (n = 30), anthropometric deficiencies (n = 94), and predefined comorbidity exclusions (cancer/chronic heart disease/gastrectomy: n = 144 + 63 + 1).