Stereologic parameters of nuclear ultrastructure as markers of the steroid receptor status in breast cancer epithelium

The nuclear specific surface density (Sv/Vv), mean nuclear area (A) and numerical density (Nv) of tumor cell nuclei from 30 primary invasive female breast carcinomas with known concentrations of estrogen and progesterone receptors (ER and PR), were morphometrically analyzed at the ultrastructural level. It was found that carcinomas with concordant positive ER and PR status contained significantly higher number of smaller nuclei per volume unit of epithelium (mean Nv = 1.5 × 106 mm −3, mean A-27 μm 2), than carcinomas of negative concordant receptor status (mean Nv = 0.8 × 10 6 mm −3, mean = 37 μm 2). Tumor cell nuclei of the former frequently displayed an elliptic shape (mean Sv/Vv = 1.16 μm −1), and had deeply invaginated surfaces, whereas nuclei of the latter were more frequently ball-shaped and exhibited a smooth-surface (mean Sv/Vv = 0.88 μm −1). The numerical density Nv (NUC/EPI) of tumor cell nuclei turned out to be a most reliable morphological marker of the concordant ER and PR status (overall efficiency = 84%, p < 0.01). The nuclear surface and volume ratio and mean nuclear area also appear to be reliable markers for terminal stages of the biochemical differentiation of breast carcinoma (overall efficiency = 79%, p < 0.05).