RESUMEN
We studied the effect of macrophage stimulator water-soluble beta-(1-->3)-D-carboxymethylglucan on the efficiency of cyclophosphamide chemotherapy in Lewis lung carcinoma. Cyclophosphamide inhibited the growth of primary tumor nodes by 57%. The preparation possessed pronounced antimetastatic activity: metastases were found in 40.9% animals. Combination therapy with cyclophosphamide and (1-->3)-beta;-D-glucan inhibited the growth of intramuscular tumors by 75-89% and reduced the incidence of metastases into the lungs by 92-94%. The therapeutic effect was most pronounced after simultaneous administration of these preparations: tumor growth was suppressed by 89.3% and metastases were found in only 7.5% animals (vs. 100% in the control). The potentiating effect of beta-(1-->3)-D-carboxymethylglucan is related to accumulation of cysteine proteinase inhibitors in the tumor tissue and plasma, but not to changes in blood cell composition.