A Study Of Radiosensitivity On Tumours In Mice Following Erythropoietin Treatment Of Carboplatin Induced Anaemia

The radiosensitivity of tumours in anaemic mice treated with erythropoietin (r-HuEPO) was studied. Anaemia was induced by a single dose of carboplatin (50mg/kg, i. v. ), resulting in a reduction in the haemoglobin concentration by 22%. In other groups the development of anaemia was prevented by r-HuEPO(1000lU/kg) s. c. , three times per week starting 6 days before the carboplatin application. Four days after carboplatin treatment, S-180 sarcomas were implanted subcutaneously onto the hind leg dor-sum. Two groups were not treated with radiotherapy showed that neither carboplatin nor r-HuEPO treatment influenced tumour growth rate. Whereas in other two groups including treatment group and control group tumours were irradiated with a single non-curative dose (lOGy) by 60Co (tumours were covered with 5mm tissue compensation by equal density Vaseline guaze) four days after implantation, resulting in a growth delay with a subsequent regrowth of the tumours. In r-HuEPO treatment group, the tumours volumes were smaller than the anaemic group and was statistically significant; the growth delay lasted longer (3. 9days vs. 3. 4days) compared with the anaemic group; the average weight of mice was significantly heavier compared with the anaemic group (30g vs. 24g)(P<0. 01)when this study ended . These results suggest that anemia induced by chemotherapy can be prevented and corrected by prophylactic r-HuEPO application, and radiosensitivity was enhanced accordingly, presumable as a result of an improved oxygen supply to tumour tissue following the raising of hemoglobin.