Identification of minimal regions of deletion at 8p23.1-22 associated with metastasis of hepatocellular carcinoma

Aims/ Background: Loss of heterozygosity ( LOH) at 8p is the most frequent chromosomal alteration in tumorigenesis of human cancers. However, the genetic change in metastasis of hepatocellular carcinoma ( HCC) still has to be investigated. Methods: We used 16 microsatellite markers informative in Japanese patients, selected from among 61 published microsatellite markers at 8p23.2- 21 to compare the frequency of LOH in primary tumours ( Tps) and metastatic tumours ( Tms) in a PCR- based analysis. Sixty- three informative cancerous lesions ( 26 were Tps, 37 were Tms) from 23 cases of HCC were used. Results: The frequency of LOH at 8p23.2- 21 with at least one marker was 19% in Tps and 68% in Tms. Allelic loss at 8p23.2- 21 was significantly more frequent in Tms than in Tps ( P= 0.0003). More specifically, the frequency of LOH at D8S262, D8S1819, D8S503, D8S1130, D8S552, D8S1109, and D8S261 in Tms was 36 - 60% respectively. Conclusions: In contrast, allelic loss at the same markers in Tp was only detected in 0 - 17% of the tumour respectively. The significant difference in the frequency of LOH at 8p between primary cancer and metastatic cancer in individual cases of HCC suggests LOH at 8p to be involved in the enhancement of tumour aggressiveness, especially during metastasis.