Prediagnostic GERD is associated with mortality among patients with gastric cancer in a nationwide cohort

We investigated the survival outcomes of patients with newly diagnosed gastric cancer with prior gastroesophageal reflux disease (GERD). In this nationwide population‑based cohort study using the Korea Central Cancer Registry database (2012–2017), patients with gastric cancer aged ≥ 30 years with national health screening records were classified into the GERD and non-GERD groups. The primary outcome was all-cause mortality, with secondary analyses including stage-specific outcomes and cause of death. Among 108,350 patients with gastric cancer, 14,237 (13.1%) were classified into the GERD group. Patients with GERD were diagnosed with gastric cancer at earlier disease stages than were those without GERD. However, all-cause mortality was higher in the GERD than in the non-GERD group (19.78% vs. 17.85%, P < 0.0001), including both gastric cancer-related and non-cancer-related deaths. The association remained after multivariable adjustment (adjusted hazard ratio, 1.13; 95% confidence interval, 1.08–1.17). The association was stage-specific, being strongest in the regional stage, followed by in the localized stage; no significant difference was observed in the distant stage. Presence of GERD in patients with gastric cancer was associated with earlier-stage diagnosis but higher mortality, suggesting that GERD may be associated with prognostic heterogeneity. Further studies should verify its potential role in risk stratification.