Prognostic significance of 18q LOH in sporadic colorectal carcinoma.

Identification of molecular alterations with implication for prognosis and sensibility to chemotherapeutic agents represents a great challenge in colorectal carcinoma treatment. Controversial results have been reported on prognostic value of chromosome 18q loss. Ninety-seven unselected patients with sporadic colorectal carcinoma Stage II and III were investigated for loss of heterozygosity at 18q D18S58 and D18S61 loci. Molecular alterations were correlated with clinicopathological data and survival. 18q loss of heterozygosity (LOH) was present in 56 per cent cases of carcinoma and was not related either to the clinicopathological characteristics of the patients or to prognosis. However, patients with LOH at locus D18S61 showed a more favorable prognosis. This finding was especially true for Stage II and untreated carcinoma. Survival was not influenced by the status of D18S58 locus. In our series, LOH at chromosome 18q does not seem to predict an unfavorable outcome. It seems of special interest the benefit that D18S61 loss of heterozygosity confers to untreated patients and patients with Stage II colon carcinoma.