Antitumoral local effect and metastatic risk of focused extracorporeal pyrotherapy on Dunning R-3327 tumors.

Abstract

We evaluated the effect of focused extracorporeal pyrotherapy on local tumor growth and metastatic potential of the Dunning R-3327 tumor inoculated into male Copenhagen Fisher rats, using the highly metastatic MAT Ly Lu cell line in 64 rats and the slightly metastatic G cell line in 60 rats. Five million cells were inoculated subcutaneously into a lower limb and the tumor volume was determined every 48 h. The local effect, the presence of lung and/or lymph node metastases and the spontaneous survival were evaluated in the treated groups (n = 30 for MAT Ly Lu and n = 29 for G) and in the sham control groups (n = 19 for MAT Ly Lu and n = 13 for G) by autopsy of the animals at successive times after treatment. A local effect of treatment was obtained for the two cell lines with complete local cure in 53% of cases. The animals developing metastases were not more numerous in the treated groups than in the control groups. Long-term survivals were obtained in the animals inoculated with the two cell lines. These results suggest that pyrotherapy exerts a local effect on the Dunning R-3327 tumor model without increasing its metastatic potential and allows long-term survivals. Controlled therapeutic trials in human cancers are envisaged.