During the past years, automated methods for analytical cytology have produced a large quantity of data on DNA-ploidy disturbances in different types of human cancers. Flow cytometry (FCM) provides a quick and precise method for determining DNA-ploidy and distribution of the cell cycle in tumours. This paper surveys DNA-aberrations in human endometrial, cervical, ovarian and breast carcinomas, and shows that prognosis is much better for diploid than for aneuploid tumors, and that the prognostic ability of DNA-patterns is proved to be much better than that of the parameters used before, such as degree of differentiation, myometrial invasion and receptor concentrations.