Antitumor efficacy of an isolated hind legperfusion with a pH-increased solution in thePliss’ lymphosarcoma graft rat model

Abstract

Background: The technique of regional isolated perfusion makes it possible to increase local levels of an anti-tumor agent, to perform the treatment procedure under hypothermia or hyperthermia, to reduce or even eliminate any systemic effect of a cytostatic on the patient. In this context, the use of isolated perfusion to modify the pH milieu of the tumor seems to be a promising strategy that could potentially ensure the anti-tumor effect. Aim: To evaluate the efficacy of a rat limb perfusion with 4% NaHCO3 solution in vivo in the Pliss' lymphosarcoma rat graft model. Materials and methods: The experiment was carried out in Wistar rats with Pliss' lymphosarcoma graft. The isolated limb was perfused with an isotonic sodium chloride solution (the control group) or a 4% sodium bicarbonate solution (the treatment group). The following parameters were assessed: tumor node growth over time, survival rate, hematology analysis at various time points of the experiment, and histological examination of autopsy samples from the tumor. Results: Median survival in the group perfused with 4% NaHCO3 (N = 6) was 17.2 days, whereas in the non-perfused group (the pathogenesis group) (N = 4) and in the group perfused with isotonic saline (N = 5) they were 13.2 and 13.6 days, respectively. The risk of death in the treatment group was lower compared to that in the control group (Cox regression model, hazard ratio 0.129; 95% confidence interval 0.0280.583; p = 0.0079). There were no significant differences in the tumor growth rate over time in the perfused groups. Conclusion: A single exposure of the tumor micro-milieu in the model with isolated perfusion of the limb with Pliss' lymphosarcoma graft does not lead to any changes in the tumor growth kinetics, but is associated with a change in the animal survival.