In vivo cell kinetic effects of cis-platinum on human ovarian cancer xenografts measured by dual parameter flow cytometry.

Dual parameter flow cytometry, measuring DNA and nuclear protein of individual cell nuclei simultaneously, makes it possible to follow cell kinetic perturbations in six distinct compartments of the cell cycle following chemotherapy in vivo. Human ovarian cancer xenografts in nude mice from a primary and recurrent tumor of the same patient were studied. The response to intraperitoneal application of cis-platinum was assessed by tumor volume measurements, changes in labeling indices by autoradiography, and dual parameter flow cytometry. Sequential tissue samples were taken from each tumor using fine needle aspirations as a microbiopsy method. Pretherapy samples were compared to multiple specimens collected up to 18 days after therapy. Morphologic changes of each specimen were also assessed. Cis-platinum affects malignant cells in the G1B, S, G2A, and G2B compartments with various intensities and different time frames, depending on the drug sensitivity of each individual tumor.