Objective: To present an overview of molecular characteristics and differences of and between preinvasive and invasive breast tumors.
Design: Review.
Setting: Oncogynecologic center, Clinic of Obstetrics and Gynecology, First Faculty of Medicine, Charles University in Prague and General Teaching Hospital, Prague.
Material and methods: Review of literature.
Conclusion: Identification of genetic and epigenetic changes in preinvasive and invasive breast tumors can help to better classify these lesions and improve and tailor their clinical management. Due to completely different biological behavior of morphologically identical lesions, it is clear that the matter of classification and clarification of their clinical behavior is hidden inside the entire genome or proteome.