LOSS OF HETEROZYGOSITY IN 8P IS ASSOCIATED WITH MICROINVASION IN COLORECTAL-CARCINOMA

Loss of heterozygosity (LOH) from the short arm of chromosome 8 is fre quent in a variety of malignancies, suggesting the presence of a tumor suppressor gene in this region. Previous studies suggested that this deletion may correlate with higher clinicopathologic stages in colorec tal cancer, but others did not support this finding; in part, this dif ficulty is due to the low heterozygosity of the RFLP markers that were used. Here we report on a preliminary investigation in which we used highly informative microsatellite markers to determine whether deletio ns of 8p are correlated with poor prognostic features. Paraffin-embedd ed tumor tissue from 15 patients was analyzed with a panel of three mi crosatellite markers that are known to be sites of frequent LOH. Fourt een of the 15 cases were informative with at least one marker, and 7 s howed LOH. Analysis of clinical features showed that there was no rela tion of 8p LOH with patient age or tumor stage, grade, location, or pa ttern of growth. However, a statistically significant correlation was seen between LOH and lymphatic, vascular, or perineural microinvasion (Fisher exact test, P = 0.01). This histologic feature is known to be a stage-independent indicator of prognosis. Our data suggest that 8p L OH may be associated with poor outcome and demonstrate the utility of these microsatellite markers for its detection. (C) 1994 Wiley-Liss, I nc.