COLON-CANCER - FROM MOLECULAR DIAGNOSIS TO CLINICAL-DIAGNOSIS AND THERAPY

Studies of tumour cell genetic alterations have demonstrated the exist ence of two distinct groups of colorectal cancers. The first one is ch aracterised by the existence of hyperploid tumour cells and frequent l oss of heterozygosity. These colorectal cancers are the mast common. T he second cme is characterised by the presence of microsatellite insta bility. Among the most frequent genetic alterations, the loss of heter ozygosity on the short arm of chromosome 17 and the long arm of chromo some 18 seems to be indicators of a pejorative prognosis. In the same way the existence of a p53 mutation in tumour cells has been demonstra ted as an independent prognostic factor in colorectal cancer. The indi cation of an adjuvant chemotherapy on the basis of such genetic altera tions remains to be demonstrated by randomised trials.