Prognostic relevance of AgNORs in tumor pathology

The importance of the analysis of the silver-stained nucleolar organizer re gions (AgNORs) for prognostic purposes in tumor pathology has been reviewed . Current available data from the literature demonstrate that the evaluatio n of the quantity of interphase AgNORs is an independent prognostic factor in several types of human tumors. Results of our investigations indicate th at AgNORs are the most powerful variable predicting survival in patients wi th pharyngeal carcinoma, multiple myeloma, male breast and prostate carcino ma. The combination of AgNOR counts and histologic pattern allows the strat ification of patients with multiple myeloma, pharyngeal and prostate carcin oma into low- and high-risk groups, which could benefit from different ther apy. Moreover, AgNOR analysis predicts response to treatment in adult patie nts with acute myelogenous leukemia, and appears as an independent prognost ic factor in a prospective study on renal cell carcinoma. Therefore, AgNOR analysis is a really important prognostic factor for several human neoplasi as. The experimental and theoretical justifications for AgNORs as a prognos tic factor are also reviewed, in particular the strict correlation between AgNOR quantity and tumor cell doubling time. Lastly, the lack of prognostic significance of AgNOR analysis in some circumstances is critically discuss ed. (C) 1999 Elsevier Science Ltd. All rights reserved.