Experimental study on the growth and proliferation kinetics of residual tumor after surgery in mouse neuroblastoma

In order to elucidate the proliferation kinetics of residual tumors after surgery, experimental studies were performed, using C-1300NB and A/J mice, tumor-host system. Mice were inoculated with C-1300NB cells in the chest and leg simultaneously, and then divided into three groups. Growth curves of chest tumors (residual tumors) in Group B after amputation of the tumor-bearing leg were significantly steeper than those of both Group A, whose tumor-bearing legs were not amputated, and Group C, whose normal legs were amputated, at the same tumor age. 3H-TdR labeling indices of chest tumors of Group B were significantly higher than those of Group A (P less than 0.05). DNA histograms of the chest tumors of Group A uniformly showed a unimodal distribution with a peak in the 2c range. On the other hand, in Group B the peak of nuclear DNA distribution shifted from the 2c range to the 4c range after amputation of tumor-bearing leg. The results indicated that an increase in cells in the DNA synthetic phase occurred in the remaining neuroblastoma after reducing the volume of tumor in host by amputation of tumor-bearing legs.