HP and gastric cancer: Background: To improve compliance with endoscopic screening for gastric cancer (GC), we assessed five biomarkers—pepsinogen I (PG I), pepsinogen II (PG II), PG I/II ratio, helicobacter pylori antibody (HP-Ab), and gastrin 17 (G17) — for secondary GC screening by comparing participation and effectiveness of traditional endoscopy and biomarker-based screening in a randomized trial with baseline results.