Background: Anal squamous cell carcinoma (SCC) develops from dysplastic anal warts. This study quantifies the expression of p53 and Ki67 in pre-invasive and invasive anal lesions.
Materials and methods: Samples of 70 patients with anal warts (n = 20), low grade anal intraepithelial neoplasia (LG AIN) (n = 12), high grade anal intraepithelial neoplasia (HG AIN) (n = 27) and anal SCC (n = 11) were stained using immunohistochemical techniques. Eight patients with normal anal skin were used as controls.
Results: Both the expression of p53 and Ki67 increased significantly (p < 0.001) and gradually as the lesions became dysplastic and invasive. The main increase in p53 expression was as the lesions progressed from anal warts (7.38 +/- 11.93-mean +/- SD) to low grade AIN (20.778 +/- 13.14).
Conclusion: p53 is involved in the progression of anal cancer and its expression increases from early in the development of pre-invasive anal lesions. p53 and Ki67 may be useful markers of early dysplasia and should be considered in the screening of high risk patients.