A rapid in vitro method for measuring cell proliferation in human breast cancer

Abstract
A method was developed for studying in vitro the cell proliferation kinetics of human breast cancer. Surgical specimens from primary tumors were studied in 56 patients. Viable cell suspensions for assay were obtained by the dissociation of tumor tissue with collagenase. Mean labeling indices of 2.43 .+-. SD 2.05 and 4.48 .+-. SD 3.73, respectively, were found after incubation with 3HTdR [3H-thymidine] for 2 and 24 h. Mean S-times of 21.9 .+-. SD 4.3 h were estimated by 3H and 14C-TdR double-labeling. The kinetic data were validated by parallel labeling studies in vivo and in vitro in 4 patients. The processing of autoradiographs using Au latensification provided slides for kinetic analysis within 3 days. The assay offers a method that is useful in the planning and monitoring of drug therapy.