ANTITUMORAL LOCAL EFFECT AND METASTATIC RISK OF FOCUSED EXTRACORPOREAL PYROTHERAPY ON DUNNING R-3327 TUMORS

We evaluated the effect of focused extracorporeal pyrotherapy on local tumor growth and metastatic potential of the Dunning R-3327 tumor ino culated 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 e ffect, the presence of lung and/or lymph node metastases and the spont aneous survival were evaluated in the treated groups (n = 30 for MAT L y 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 devel oping metastases were not more numerous in the treated groups than in the control groups. Long-term survivals were obtained in the animals i noculated with the two cell lines. These results suggest that pyrother apy exerts a local effect on the Dunning R-3327 tumor model without in creasing its metastatic potential and allows long-term survivals. Cont rolled therapeutic trials in human cancers are envisaged.