Argyrophilic nucleolar organizer region (AgNOR) area per nucleus as a prognostic factor in breast cancer

Whether argyrophilic nucleolar organizer region (AgNOR) is a predictor of prognosis in breast cancer is controversial. The semiquantitative procedure used to calculate interphasic argyrophilic dots optically is neither reliable nor reproducible. We measured the mean area of AgNOR dots, the mean AgNOR area per nucleus (MA), and the mean AgNOR number per nucleus (MN) by automated image analysis in specimens from 131 patients with breast cancer. Higher MA (> 7.41 microns2), detected in 22 (16.8%) of 131 patients, did not correlate with clinicobiologic variables, except for DNA ploidy status. Overall survival was significantly better in patients with lower MA than in those with higher MA. On multivariate analysis, MA was a significant independent factor, followed by nodal status. These findings indicate that expression of AgNOR should be evaluated in terms of area occupied and that the mean area of AgNOR per nucleus (MA) is an important prognostic factor in the overall survival of breast cancer patients.