[Kinetics and composition of cell populations in malignant astrocytomas]

The cell generation time (Tc) and the growth fraction (GF) were studied in 4 malignant astrocytomas removed during the first operation. These parameters varied within a wide range in the various areas of each tumor. In 4 areas of one of the tumors, for instance, the Tc values were 545, 70, 26, and 17 hrs and the values of GF were 0.29, 0.59, 0.58, and 0.25, respectively. In the other tumors the Tc fluctuations were 66-179, 14-200 and 20-272 and the GF fluctuations 0.10-0.68, 10.07-0.31, and 0.21-0.56. These data do not agree with the results obtained by Hoshino et al. who studied recurrent glioblastomas and found the fluctuations in Tc values within one and the same tumor to be much less. These discrepancies indicate that from the standpoint of cell kinetics recurrent astrocytomas are a more favourable object for chemotherapy than primary tumors.