Trends in incidence, treatment and survival of gastric adenocarcinoma between 1990 and 2007: A population-based study in the Netherlands
Background: Survival of gastric cancer in the Western world remains poor. We conducted a retrospective population-based study to evaluate trends in incidence, treatment and outcome of gastric adenocarcinoma. Methods: All patients diagnosed with gastric adenocarcinoma during 1990-2007 in the Dutch Eindhoven Cancer Registry area were included (n = 4797). Trend analyses were conducted for incidence, mortality, tumour and patient characteristics, treatment and crude overall survival, according to tumour location (cardia versus non-cardia). Temporal changes in the odds of undergoing surgery and the risk of death were analysed by means of multivariable regression methods. Results: Age-standardised incidence decreased among males (24-12 per 100,000 inhabitants) and females (10-6); mortality rates decreased at a similar pace. The proportion of cardia tumours remained stable. Stage distribution worsened over time among patients with cardia (stages I and II: 32% in 1990-1993 and 22% in 2006-2007, p = 0.005) and non-cardia (stage IV: 33% in 1990-1993 and 40% in 2006-2007, p = 0.0003) cancer. Chemotherapy rates increased in all settings. Five-year survival worsened over time for patients with non-cardia tumours. Age and stage had significant influence on survival after stratification for tumour localisation. After adjustments for relevant factors (i.e. stage), the risk of death decreased since the late 90s for patients with a cardia tumour (hazard ratio 0.8, p = 0.01). Conclusion: The absence of improvement in survival rates indicates the need for earlier detection and prospective studies to evaluate new therapy regimens with standardised surgery and pathology.