Hilar cholangiocarcinoma

New p53 mutations in hilar cholangiocarcinoma

BACKGROUND

Inactivation of the tumour suppressor gene, p53, is the commonest genetic abnormality in human cancer. The study of the type of p53 mutation in a given tumour may provide prognostic information, clues to aetiology and become useful for therapeutics.

MATERIALS AND METHODS

The molecular characterisation of p53 was performed by restriction analysis, denaturing gradient gel electrophoresis, and gene sequencing for exons 5-9.

RESULTS

We report, p53 mutational analysis in exons 5-9 in 29 European patients with hilar cholangiocarcinoma who underwent attempted resection. Four patients (14%) showed somatic single nucleotide substitutions with amino acid changes (146, 163, 175, 158, and 175) with one showing mutations in two different positions involving a loss of two CfoI sites. All the mutations occurred in exon 5. Three patients had a germline polymorphism (10%) with a silent substitution in codon 213 (exon 6).

CONCLUSIONS

The systematic screening for p53 mutations in European patients with hilar cholangiocarcinoma has shown that the type of mutation (except 175) is different and its incidence is much lower when compared to the pattern previously reported for intrahepatic cholangiocarcinoma in East Asian patients. A probable explanation is that the presence and type of p53 mutation is dependent on geographic and environmental factors which vary in different populations.

Segment III cholangiojejunostomy for palliation of malignant hilar obstruction

Between 1984 and 1992, 26 patients with obstructive jaundice due to malignancy at the liver hilum were treated by segment III Roux-en-Y cholangiojejunostomy. Twenty-two patients had hilar cholangiocarcinoma, one carcinoma of the gallbladder, one pancreatic carcinoma, one recurrent gastric carcinoma and one lymphoma. Seventeen patients had no complications in the postoperative period and six had complications; there were three postoperative deaths. Eighteen of the 23 surviving patients experienced complete resolution of jaundice for at least 3 months. Four developed recurrent jaundice and three had episodes of cholangitis before death. Segment III cholangiojejunostomy offers effective palliation for most patients with irresectable hilar malignancy.

Changing trends in the management of extrahepatic cholangiocarcinoma

A series of 107 patients with cholangiocarcinoma diagnosed between January 1980 and December 1991 is reported. Changing patterns of investigation and treatment in the periods 1980-1985 and 1986-1991 are analysed. There was a decrease in the use of percutaneous transhepatic cholangiography in the second period (86 versus 51 per cent of patients) but increased use of endoscopic retrograde cholangiography (19 versus 71 per cent) and computed tomography (8 versus 59 per cent). The overall resectability rate (17 per cent) was similar to those of other reported series but greater in the second period (8 versus 21 per cent). Palliation by endoscopic and percutaneous stenting was associated with a high incidence of recurrent cholangitis (55 per cent) and jaundice (35 per cent). During the second 6-year period, more effective palliation was achieved by segment III cholangiojejunostomy with a lower incidence of recurrent cholangitis (19 per cent) and jaundice (19 per cent). Overall prognosis for patients with this condition is grim and efforts must usually be aimed at providing the most appropriate palliation.

Loss of constitutional heterozygosity on chromosomes 5 and 17 in cholangiocarcinoma

It has been established that loss of tumour suppressor genes is crucial in carcinogenesis. There has been no reported study on searching for tumour suppressor genes in cholangiocarcinomas as yet. In order to investigate the loss of heterozygosity (LOH), which may represent such gene loss, in cholangiocarcinoma, we studied 14 patients with this tumour using restriction fragment length polymorphism analysis. Twenty-two probes assigned to chromosomes 1, 5, 7, 9, 11, 12, 13, 14, 16, 17 and 18 were used. Allelic losses were found in chromosomal regions 5q35-qter and 17p13. Loss of genetic material in these regions in cholangiocarcinoma was shared with hepatocellular carcinoma. Probes for other chromosomes have as yet shown no consistent LOH. In conclusion, this study for the first time showed LOH on chromosomes 5 and 17 in cholangiocarcinoma.