Expression of Nuclear β-Catenin in Rectal Versus Colonic Cancers

Rectal cancers have more local relapses than colonic cancers. Since nuclear -catenin plays an important role for the proliferation capacity of cells, we wanted to evaluate whether there may be differences in the expression pattern of nuclear -catenin between rectal and colonic adenocarcinomas, explaining the observations made in clinical practice. Sections from 235 rectal adenocarcinomas treated surgically in the years 1992 – 2000 were immunohistochemically stained for -catenin. Nuclear immunopositivity was recorded. The results were compared to the results of a similar examination performed earlier on 162 colonic cancers. We found a higher protein expression of nuclear -catenin in rectal cancers than in colonic cancers. No statistically significant correlation was observed between nuclear expression of -catenin in rectal cancers and cancer specific survival. Our findings indicate that rectal cancers and colonic cancers are biologically different. The results might partly explain the clinical difference observed between rectal cancers and colonic cancers.