Geographical variations in the incidence of oesophageal cancer in Sweden
Background: Geographical variations in the incidence and tumour stage distribution of oesophageal cancer in Sweden are not well characterised.
Methods: Using data from the Swedish Cancer Registry over 45 years (1972–2016), we compared the age-standardised incidence rates of oesophageal cancer by histological type across all seven national areas (in five-year periods) and 21 counties (in 15-year periods) in Sweden, and assessed the geographical distribution of tumour stage at diagnosis since 2004.
Results: The incidence rate of oesophageal adenocarcinoma increased in all national areas and counties and in both sexes over time, while the rate of oesophageal squamous cell carcinoma decreased from the 1980s onwards. In the latest period (2012– 2016), the incidence rate of adenocarcinoma in men ranged from 3.5/100,000 person-years in West Sweden to 6.2/100,000 person-years in North Middle Sweden. At the county level, the rate of adenocarcinoma in men was lowest in Jämtland (2.7/100,000 person-years) and highest in Gotland (6.2/100 000 person-years) in 2002–2016. The incidence rates of both adenocarcinoma and squamous cell carcinoma in women were below 2/100,000 person-years in all national areas and counties in the latest calendar periods, i.e., 2012–2016 and 2002–2016, respectively. The proportion of patents with tumour stage IV ranged from 22% in Stockholm area to 31% in Middle Norrland, while at the healthcare region level it was lowest in Stockholm healthcare region (23%) and highest in North (30%) and Uppsala-Örebro (29%) healthcare regions.
Conclusion: There are considerable geographical variations in the incidence and tumour stage distribution of oesophageal cancer in Sweden.