Polymorphism of Ag-stained nucleolus organizer regions in lymphocytes of patients with ovarian or breast adenocarcinoma.

The Ag-stainability of nucleolus organizer regions (NORs) in the acrocentric chromosomes identified by Q-banding was studied in 45 female patients with adenocarcinoma of the ovary or breast and in 45 healthy females. Significantly higher frequencies of Ag(+)NORs per individual (8.8 and 8.3; P less than 0.05), in the G group chromosomes (3.6 and 3.2; P less than 0.05), and in chromosome 21 (1.9 and 1.7; P less than 0.02) were found in patients, compared with controls. Despite the lack of significant differences in NORs between the groups of patients with ovarian and breast adenocarcinoma, the main difference between the patients and controls was due to the patients with adenocarcinoma of the ovary, where a significantly higher frequency of Ag(+)NORs was found in chromosomes 21 (P less than 0.01) and 13 (P less than 0.05).