Cell kinetic study of human cancers transplanted to nude mice.

Using 3H-TdR pulse labelling, the cell kinetics of four, serially transplantable, human tumors were studied in athymic nude mice. Squamous cell carcinoma of the lung, tongue and esophagus showed relatively similar cell kinetic parameters. The growth of an oat-cell carcinoma was initially very slow in mice and its growth fraction was unexpectedly small with a relatively low labelling index. Its postmitotic phase was very short. It was concluded that the nude mice/human tumor system may be useful for cell kinetic studies of human tumors from the standpoint of tumor biology and therapy.