Systemic thermochemotherapy in a rat model
Rotstein, L.E.; Daly, J.; Rozsa, P.
Canadian Journal of Surgery. Journal Canadien de Chirurgie 26(2): 113-116
1983
ISSN/ISBN: 0008-428X PMID: 6824995 Document Number: 198714
The purpose of this study was to determine the effects of systemic hyperthermia, with and without Adriamycin, on two rat tumour models. Fischer rats were implanted subcutaneously with either a methylcholanthrene-induced sarcoma or a transitional cell carcinoma. In the first experiment, 32 rats with tumour volumes of 1 cm3 were divided into four groups of 8 rats receiving: (a) Adriamycin alone (2 mg/kg intraperitoneally) (group 1), (b) systemic hyperthermia alone (water bath immersion to a rectal temperature of 41.5 degrees C for 30 minutes) (group 2), (c) Adriamycin and systemic hyperthermia (group 3) or (d) immersion in water bath at 37 degrees C for 30 minutes (control group) (group 4). Serial tumour volume and animal survival were monitored. No differences were seen among the groups in either tumour system. In a second experiment, an identical protocol was used except that each animal received its respective treatment three times, at weekly intervals. In the rats implanted with methylcholanthrene-induced sarcoma, tumour volume was lower in group 3 than in control group 4, beginning at day 23 (37.5 +/- 8.2 cm3 vs. 52.3 +/- 9.6 cm3 [p less than 0.05]). Systemic hyperthermia or Adriamycin alone did not alter tumour growth in relation to the control group. In the transitional cell carcinoma system, tumour volume was decreased in both groups 1 and 3 at day 35 (group 1 = 32 +/- 5.4 cm3, group 3 = 28.1 +/- 12 cm3 vs. group 4 = 48.8 +/- 9 cm3 [p less than 0.05 for each]). Adriamycin with systemic hyperthermia was no more effective than Adriamycin alone. Tumour growth was similar in groups 2 and 4. These data demonstrate that multiple treatments with Adriamycin and systemic hyperthermia were effective in decreasing the rate of tumour growth in rat tumour models, whereas a single exposure had no effect.