Background: During recent decades, an increase in the incidence of certain oesophago-gastric cancer subtypes has been reported in some countries. This study sought to analyse oesophageal and gastric cancer incidence trends in Spain by sex, site and morphology for the period 1980-2004.
Patients and methods: Oesophageal and gastric cancer cases were drawn from 13 Spanish population-based cancer registries. Time trends in sex- and age-standardised cancer incidence rates were analysed by subsite and histology over the study period, using change-point Poisson models.
Results: Age-standardised oesophageal cancer incidence rates failed to register a significant trend over the study period. Overall, gastric cancer decreased from 27.21 and 13.44 cases per 100,000 person-years in 1980-84 to 20.21 and 8.68 in 2000-04, among men and women, respectively. Whereas oesophageal adenocarcinomas increased by approximately 5% per annum in both sexes, gastric cardia cancer increased during the study period in males only, though this increase was less pronounced. Among men, oesophageal squamous cell cancer and non-cardia cancer rates declined steadily from the mid-1980s onwards. Over the same period, there was a marked decrease in the incidence of oesophago-gastric cancer presenting with unspecified subsite or morphology.
Conclusions: Changes in the prevalence of the main risk factors for these tumours might only partly explain oesophageal and gastric cancer rate trends by subtype. Reclassification, however, would appear to account for most of the divergence in oesophageal and gastric cancer trends by subtype over the study period.