title: [Colorectal carcinogenesis, frequency and significance of genetic alterations: deletion of the short arm of chromosome 1, and initiating event].
abstract: Cytogenetic anomalies described in colo-rectal tumors are numerous. Despite the complexity and the number of the anomalies observed, a combined study of their frequency and of the stage of prognosis of the tumors suggests that the evolution from colonic adenoma to carcinoma often follows a sequence of events comprising a 5q15-22 deletion (DCC), and a 17p deletion (P53). It even seems likely that in many cases, these events are not constant and that others might lead to the same phenotypic transformation. Chromosome 1 involvement in structural rearrangements has been demonstrated in numerous forms of cancers, malignant blood disorders and in solid tumors. In colorectal adenocarcinoma anomalies have been described on short and/or long arms. In a case of adenoma with mild dysplasia a deletion of the distal part of the short arm of chromosome 1 was observed as an isolated cytogenetic anomaly, suggesting it would be an early, perhaps triggering, event for the tumour development. A cytogenetic study in a series of colo-rectal tumours, researches on loss of heterozygosity and microsatellite instability lead to consider deletions at chromosome 1p as an early event in human colorectal tumourigenesis.
authors.affiliation: Service d'Hépato-Gastro-Entérologie, Hôpital Cochin, Paris.
authors.forename: D
authors.initials: D
authors.lastname: Couturier
authors.forename: M H
authors.initials: MH
authors.lastname: Couturier-Turpin
mesh_terms: D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000628:therapy; D020022:Genetic Predisposition to Disease; D006801:Humans; D011379:Prognosis