Breast cancer will increasingly become a disease affecting the lives of older women, especially in more developed countries, the prevalence rising up to 7% over age 70 in the near future. A review of the population -based literature and an analysis of the data of the Eind-hoven Cancer Registry and European data regarding the diagnosis, treatment and prognosis showed that the proportion with unstaged and advanced disease (stages III and IV) is higher among elderly patients compared to younger ones and that their treatment is generally less aggressive, although the proportion receiving chemotherapy is increasing since the early 1990s. Disease specific (or relative) survival of elderly breast cancer patients is generally lower and the prevalence of serious (life expectancy affecting) co-morbidity is higher (>50% in patients over age 70). Because of large individual variations in physical and mental conditions, limited evidence from RCTs and personal preferences prevailing in the decision-making process, treatment of older breast cancer patients seems difficult to fit into guidelines. Therefore, alternative research strategies are needed to understand and improve the care for the elderly breast cancer population, such as descriptive (registry-based) studies and a qualitative, individual-based approach.