Pediatric embryonal tumors were the first malignancies in which a response to chemotherapy was recognized and they have since been important clinical models in developing many principles of cancer treatment. The molecular origins of embryonal tumors were the focus of the 1990 Forbeck Forum, where laboratory researchers and clinical oncologists met to exchange ideas about the regulation of cell differentiation and growth and its disruption in childhood cancer.
The forum first addressed childhood cancer as a genetic disorder. A chain of sequential genetic events my lead to the development of embryonal tumors and contribute to their highly malignant behavior. Wilms tumor, for example, may develop in a child whos kidney cells failed to differentiate and mature normally during embryonic development. Neuroblastoma and retinoblastoma may develop similarly. Within this context the forum then focused on molecular studies emphasizing the role of tumor suppressor genes in the development of childhood tumors. Malignant (cancerous) changes in cells at the molecular level are often associated with the loss of genetic material, which appears to be a sensitive indicator of the site of tumor suppressor genes on a chromosome, the structure in the cell's nucleus that carries the genes. The loss of genetic material from tumor cell chromosomes appears to have great imporance in the development of cancer.