CHROMOSOME ALLELE LOSS IN COLORECTAL LIVER METASTASES AND ITS ASSOCIATION WITH CLINICAL-FEATURES

Molecular genetic changes are better characterized in colorectal carci noma than in other common adult tumours. Consistent allele losses, or loss of heterozygosity (LOH), on chromosomes 5q, 17p and 18q have been well established. These changes are associated with the prognosis of the disease. Little is known of such changes in liver metastases of co lorectal origin. The extent of allelic loss and its association with c linical features were investigated in 19 patients with colorectal live r metastases by using 24 probes to detect restriction fragment length polymorphism. A high frequency of LOH on chromosomes 5q, 17p and 18q w as found in these secondary tumours. No consistent loss has so far bee n shown in any other chromosome. The frequency of allele loss correlat ed significantly with prognostic features such as the number and size of liver secondaries (P < 0.005), metastasis to the lymph nodes (P < 0 .01) and curative or palliative operation (P < 0.02).