title: A perspective on tumour progression.
abstract: During their natural history, tumours may acquire new phenotypic traits. This process, tumour progression, becomes clinically important when tumours acquire the ability to invade and metastasize or when they develop drug resistance. An acquired genetic instability modulated by selection likely contributes to this progression. More than one genetic mechanism is probably involved, a small number of point mutations being complemented by karyotypic events, gene amplification and altered gene expression. More complicated traits, such as the ability to invade and metastasize, may be acquired through the inappropriate and disorganized reexpression of genetic programs suppressed during embryologic development.
authors: Princess Margaret Hospital, Toronto, Ont.
authors: W S
authors: WS
authors: Kendal
mesh_terms: D004273:DNA, Neoplasm / Q000235:genetics; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007621:Karyotyping; D016296:Mutagenesis; D009361:Neoplasm Invasiveness; D009369:Neoplasms / Q000235:genetics / Q000473:pathology*; D012334:RNA, Neoplasm / Q000235:genetics
chemical_list: D004273:DNA, Neoplasm; D012334:RNA, Neoplasm