Abstract

Over the last forty years our knowledge of the genetics of human tumours, nature of oncogenesis and tumour suppressor genes and their mechanisms of action has improved considerably. Still, as the final solution of the problem of human tumours has not been solved alternative approaches are being developed. The concept of human tumour stem cells is one possible way to understand the nature of tumours and to design principally new modalities of diagnosis and treatment. According to this concept, tumours are not „diseases of our genes“ but are rather caused by abnormal individual development of cells. The bulk mass of tumours is heterogeneous, containing cells in different stages of development and only a relatively small proportion of them, namely tumour stem cells, are the ones able to carry on the tumour phenotype to recipient animals and cause metastases. In this paper we describe the concept of tumour stem cells in the context of breast tumours.