Expression of Ki-67 can assist in predicting recurrences of low-grade anal intraepithelial neoplasia in AIDS.

PURPOSE: The incidence of anogenital squamous-cell carcinoma was observed to have increased since the beginning of the human immunodeficiency virus infection epidemic among male homosexuals, both with acquired immunodeficiency syndrome and without acquired immunodeficiency syndrome. It seems that immunosuppression is the most important risk factor for the progression of anogenital lesions, recurrences of anal condyloma, and development of anal carcinoma, in particular in acquired immunodeficiency syndrome. High-grade anal intraepithelial neoplasia was predominantly observed in the human immunodeficiency virus-positive men. We have also observed a high rate of recurrences of anal lesions in cases of high-grade anal intraepithelial neoplasia. However, there are many cases of recurrences of low-grade anal intraepithelial neoplasia that cannot be predicted by routine histologic studies. By using immunohistochemical methods, we studied the expression of Ki-67 in epithelial cells of low-grade anal intraepithelial neoplasia of patients with acquired immunodeficiency syndrome to try to predict recurrence of these lesions.

METHODS: Anal biopsies of 38 patients were studied retrospectively. Of these patients, 14 had no recurrences (Group 1), and 24 patients had recurrence of the anal lesions before one year of follow-up (Group 2).

RESULTS: The median percentage of Ki-67-positive cells in Group 1 was 6.3 +/- 7.03 and in Group 2 was 24.1 +/- 16.72. The difference between Groups 1 and 2 was statistically significant (P < 0.001).

CONCLUSIONS: Our results showed a high correlation between the percentage of Ki-67-positive cells and recurrences. We concluded that Ki-67 counting in low-grade anal intraepithelial neoplasia can aid in predicting recurrences and therefore aid in the follow-up of these patients.