Trends in the survival of patients diagnosed with breast cancer in the Nordic countries 1964-2003 followed up to the end of 2006

Abstract

Background: Breast cancer is the leading cancer among women worldwide in terms of both incidence and mortality. European patients have generally high 5-year relative survival ratios, and the Nordic countries, except for Denmark, have ratios among the highest.

Material and methods: Based on the NORDCAN database we present trends in age-standardised incidence and mortality rates of invasive breast cancer in the Nordic countries, alongside 5- and 10-year relative survival for the period of diagnosis 1964-2003 followed up to the end of 2006. Excess mortality rates are also provided for varying follow-up intervals after diagnosis. The analysis is confined to invasive breast cancer in Nordic women.

Results: Incidence increased rapidly in all five countries, whereas mortality remained almost unchanged. Both incidence and mortality rates were highest in Denmark. Between 1964 and 2003 both 5- and 10-year relative survival increased by 20-30 percentage points in all countries, and 10-year survival remained around 10 percentage points lower than 5-year survival. Relative survival was lowest in Denmark throughout the period, with a 5-year survival of 79% for years 1999-2003, but 83-87% in the other countries. From 1964 the youngest women had the highest survival ratios up until the introduction of screening, when a shift occurred towards higher survival among age groups 50-59 and 60-69 in each country, except for Denmark. Excess death rates during the first months after diagnosis were highest in Denmark.

Conclusion: Breast cancer survival is high and rising in the Nordic countries, and probably relates to the early implementation of organised mammography screening in each country except Denmark and a high and relatively uniform standard of living, diagnosis and treatment. Denmark stands out with higher mortality and poorer survival. The major determinants may include a failure to instigate national breast screening and a greater co-morbidity resulting from a higher prevalence of both tobacco smoking and alcohol consumption.