[Descriptive epidemiology: development of incidence over time, geographical and social differences, risk factors, etc].

Breast cancer is the most frequent malignant disease in Danish women, with 4,006 incident cases and 1,333 deaths in 2001. The incidence has increased since approximately 1960, while mortality has remained relatively stable. In the era before implementation of mammography screening, there was a 20% regional and a 50% socioeconomic difference in both incidence and mortality. Future trends in breast cancer incidence are determined by present risk factors, where particularly the high age at first birth and the increased prevalence of obesity are expected to push the trend upwards.