Hormones are implicated in various types of cancer, however, several aspects of steroid activity on carcinogenesis remain elusive. Recent progress has made it possible for us to directly study the biological mechanisms of disease development, including hormone−cancer relationships, from numerous viewpoints, from numerous viewpoints, including genome abnormalities. One tool is comparative genomic hybridization array (aCGH). Furthermore, it is possible to identify the so-called “cancer signature” by gene expression profiling, which provides new information about the role of steroids on carcinogenesis. DNA mutations and gene expression abnormalities may be associated with hormone-related cancer. The recent discovery of microRNA provides new opportunities for understanding the fine regulation of gene expression in cancer cells, and the role of microRNA in the relationship between hormones and cancer. From these experimental models we should be able to rapidly develop translation-to-treatment protocols. The final goal should be to design specific labs on a microchip for prognosis and therapy of individual patients. While in clinical research there is renewed attention to stratification of patients, especially those at high risk.