title: The proliferative patterns of human breast cancer cells in vivo.
abstract: The cell proliferation pattern in human breast cancer has been studied in eight patients in vivo using intravenously administered 3HTdR as a pulse and as a continous label. Two to 4% of the tumor cells were engaged in DNA synthesis in six patients, and 7% and 11%, respectively, in two others. From the composite percent labeled mitosis curve the estimated time for G1 + (M/2) was about 4 hours and for DNA synthesis about 24 hours. Many cells which entered the cycle spent longer intervals in DNA synthesis and in the post-DNA synthetic phase before entering mitosis. There was a wide range of intermitotic times among the tumor cells. These findings are of significance in the planning of drug therapy.
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division; D004273:DNA, Neoplasm / Q000096:biosynthesis; D005260:Female; D006801:Humans; D007700:Kinetics; D008875:Middle Aged; D013936:Thymidine / Q000008:administration & dosage / Q000378:metabolism
chemical_list: D004273:DNA, Neoplasm; D013936:Thymidine