Quantification of Argyrophilic Nucleolar Organizer Regions in Estrogen Receptor Positive and Estrogen Receptor Negative Ductal Breast Carcinomas

Argyrophilic nucleolar organizer regions (AgNORs) analysis of 20 estrogen receptor positive (ER+) and 16 estrogen receptor negative (ER-) invasive ductal breast carcinomas was performed. The quantification of AgNORs was determined by using morphometrical method in three ways: 1) mean number of AgNORs per nucleus counted on a 100 random nuclei, 2) mean number of AgNORs per nucleus counted on 200-300 nuclei in fields chosen by "the chess fields" method, and 3) mean number of AgNORs on the nuclear surface unit. A significant difference in mean number of AgNORs per nucleus and on unit of the nuclear surface between estrogen receptor positive (ER+) and estrogen receptor negative (ER-) invasive ductal breast carcinomas was observed (p<0.001). The mean number of AgNORs was higher in ER– than in ER+ invasive ductal breast carcinomas. Despite interobserver variability in counting AgNORs, comparison was completed as well as the evaluation of validity of three stated ways of quantification of nucleolar organizers. Our results suggest more rapid proliferative activity in ERthan in ER+ breast cancers.