The distribution of TP53 genotypes did not differ between APC<sup>1311/+</sup> pigs with low (LP) and high (HP) number of colon polyps. p53 mRNA expression was analysed in distally located normal mucosa samples of wild-type pigs, APC<sup>1311/+</sup> LP and HP pigs, and also in distally located polyp samples histologically classified as low-grade (LG-IEN) and high-grade intraepithelial dysplastic (HG-IEN) from APC<sup>1311/+</sup> pigs. p53 mRNA expression was found to be significantly elevated in HG-IEN compared to LG-IEN samples (p = 0.012), suggesting a role for p53 in the early precancerous stages of polyp development.
We conclude that it is important to analyze p53 mutations in colonic polyps, especially when the cut end of the polyp is difficult to evaluate histologically, in order to predict recurrence.