[Breast cancer. Epidemiology and other factors related to incidence in various populations].

An extensive review of epidemiology, etiology, age, genetic factors, race, alimentary habits and hormonal patterns have been analysed in studies concerning patients with breast cancer. The role of other factors (the age of menopause, the geographic distribution, the action of reserpine and many possible causes) are also discussed. The evidences observed in many studies performed in the last years in different countries are compared but definitive data cannot be reached. The material reported in these studies is not homogeneous and this review can only indicate the problems still present in this field and the subjects we need to investigate in the next years.