ADVERSE-EFFECTS AT ADJUVANT TREATMENT OF LIVER METASTASES IN RAT WITHRSU-1069 PLUS MICROSPHERES, OR LIPOSOMAL MTP-PE

Rats were inoculated via the portal vein with a suspension of tumor ce lls from a transplantable dimethylhydrazine-induced adenocarcinoma of rat colon. In one set of experiments, the bioreductive drug RSU-1069 w as injected once via the portal vein with or without degradable starch microspheres (DSM) 10 mins after tumour cell inoculation. In another set the immunostimulator liposomal-encapsulated muramyl tripeptide pho sphatidyl-ethanolamine (MTP-PE) was injected via the portal vein ol pe nile vein 1 day before tumour-cell inoculation and then twice a week. The experiments were finished after 2 to 3 weeks. Tumour take, numbers and volumes were measured Results: RSU-1069 enhanced tumor growth whe n combined with DSM. Liposomal MTP-PE also increased tumour growth. Co nclusion: A bioreductive drug combined with microspheres, known to sup press the growth of an established tumour, may enhance its growth in t he adjuvant setting. An accepted immunostimulator may enhance tumour t ake. Drugs used for the treatment of tumours must be carefully employe d, if applied in an adjuvant setting. The effect on the normal immune system should be further studied.