Molecular cytogenetics of human testicular germ cell tumors

It was not until 1960, with the finding of the Philadelphia chromosome in chronic myelocytic leukemia (Nowell and Hungerford 1960), that the first specific chromosomal abnomlality was definitively associated with human cancer. This in spite of the fact that already more than 40 years earlier cancerous growth was associated with an aberrant genome (Bayed 1914). The main reason for this delay was the lack of suitable tools for isolation and identification of human chromosomes. After the development of specific staining methods in the early seventies, initially mainly non-solid tumors were cytogenetically analysed because their meta phases were more easily obtained. Subsequently with the development of more recent cytogenetic techniques, chromosomal analysis of solid tumors became more feasible. A wide variety of chromosomal abenations are currently identified in human neoplasia (for review; Mitelman et a1. 1997). These comprise numerical changes, resulting in gains or losses of whole chromosomes, stmcturaI changes as translocations, inversions, deletions, homogeneously stained regions (HSRs) and double minutes (DMs).