Incidence, Stage, Treatment, and Survival of Noncardia Gastric Cancer.

IMPORTANCE: Gastric cancer is the fifth most common cancer worldwide, and investigating its incidence, characteristics, treatment, and outcomes over the past decades can help in selecting clinical strategies and future research directions.

OBJECTIVE: To analyze the trends in incidence, staging, and treatment of gastric cancer.

DESIGN, SETTING, AND PARTICIPANTS: This nationwide, population-based cohort study included patients diagnosed with noncardia gastric cancer (NCGC) between 1989 and 2021 in the Netherlands.

MAIN OUTCOMES AND MEASURES: Differences in tumor characteristics, treatment, and survival were analyzed per fixed time periods (1989-1993, 1994-1998, 1999-2003, 2004-2008, 2009-2013, 2014-2018, and 2019-2021).

RESULTS: In total, 47 014 patients (median [IQR] age, 73 [64-80] years; 28 032 [60%] male patients) were identified with mostly adenocarcinomas of the antrum region (when location was known). Age-standardized incidence decreased from 20.3 to 6.1 per 100 000 person-years between 1989 and 2021. During the study period, unknown T and N stages were recorded less frequently, and metastatic disease was diagnosed more frequently (1989-1993: 2633 of 9493 patients [28%]; 2019-2021: 1503 of 3200 patients [47%] in 2019-2021). Over time, fewer patients with metastatic disease underwent surgery with or without other treatment modalities (68% in 1989-1993 vs 64% in 2019-2021), and palliative chemotherapy in metastatic NCGC increased from 9% to 40%. For patients with nonmetastatic disease, 5-year relative survival improved from 28% (95% CI, 26.5%-29.2%) to 36% (95% CI, 33.5%-37.6%) between 1989 and 2021. For patients with nonmetastatic disease undergoing a resection, 5-year survival increased from 40% (95% CI, 38.3%-41.8%) to 51% (95% CI, 47.9%-53.3%). For patients with metastatic disease, 1-year relative survival increased from 10% (95% CI, 8.7%-11.1%) to 19% (95% CI, 17.2%-21.6%), but 3-year relative survival remained poor at 5% (95% CI, 3.6%-7.5%).

CONCLUSIONS AND RELEVANCE: In this nationwide cohort study involving 47 014 patients diagnosed with NCGC (1989-2021), the results showed a decrease in incidence, more accurate staging, a shift in treatment modalities, and improved patient survival.