A mechanism of tumourigenesis: retrodifferentiation and reontogeny in cancer and its clinical significance.

A general theory for the origin and maintenance of the neoplastic state in tissues is presented. Cancer is described as a disease of abnormal cell and tissue differentiation, and its underlying cause is identified in the process of blocked reontogeny. Data are presented which support this hypothesis and show the striking similarities at the molecular level between neoplastic, embryonic and regenerating tissues. The hypothesis suggests that numerous potentially useful (in the clinical sense) proteins, all of them members of early development, may be associated with neoplasms. It is suggested that research aimed at extending the identification and measurement of these proteins will make a significant contribution to the clinical management of cancer and may lead to the development of easy and cheap screening techniques for the early diagnosis of neoplastic disease in man.