p53 Protein accumulation is a specific marker of malignant potential in Barrett's metaplasia.

Our aim was to determine the sensitivity and specificity of p53 accumulation as a marker of malignant potential in Barrett's metaplasia (BM). One hundred eighty biopsies from 61 patients with BM were evaluated for p53 accumulation by immunohistochemistry. Of 25 patients with LGD, 9 had p53-positive biopsies, and of these 5 (56%) developed HGD/CA, whereas 16 had p53-negative biopsies and none (0%) developed HGD/CA after similar follow-up times (P = 0.0108). As a marker of malignant potential in BM, p53 accumulation has a sensitivity of 100%, specificity of 93%, and a predictive value of a positive test of 0.56, compared to sensitivity of 100%, specificity of 64%, and predictive value of a positive test of 0.2 for a histologic diagnosis of LGD. We conclude that: (1) p53 accumulation is more specific and has better predictive value for subsequent development of HGD/CA than histologic diagnosis of LGD. (2) Patients with LGD and p53-positive biopsies are more likely to develop HGD/CA; therefore, they should be followed up more closely than those with LGD and p53-negative biopsies.