In vitro cultivation of xenotransplanted human breast-cancer cells.

Xenotransplanted human breast-cancer tissue growing in the second to the ninth passage in nu/nu mice and normal tissue from nu/nu mice was cultivated in vitro. Thirty-two of fifty-two (62%) cultures grew successfully and have been analyzed. The cells were observed using phase-contrast microscopy and May-Grünwald-Giemsa staining. The following cell types could be distinguished: normal fibroblast-like cells (FC), normal epithelial-like cells (EP I), abnormal epithelial-like cells (EP II), and degenerated or dying cells (DC). After staining, the nuclear area of all cell types was measured. The results were: FC = 280 micrometers 2, EP I = 320 micrometers 2, and EP II = 800 micrometers 2. They were compared with the nuclear area of human breast-cancer cells obtained by aspiration biopsy.