The therapeutic effects of an immunopotentiator, PS-K, on 3-methylcholanthrene-induced autochthonous tumors in C57BL/6 mice in combination with the surgical removal of primary sites.
We investigated the therapeutic effects of an immunopotentiator PS-K on recurrent or metastatic tumors observed after the surgical removal of MCA-induced primary tumors in autochthonous C57BL/6 mice and on the survival time of treated mice. The MST of mice treated with PS-K at various times (59.8-63.4 days) was prolonged as compared with that of mice treated by surgery alone (48.6 days). Local recurrence of tumors was found in 36 of 66 mice (54.6%) treated by surgery alone, whereas it was inhibited significantly (P less than 0.05) when treatment with PS-K was started 1 day after the surgery and occurred in 22 of 64 mice (34.4%) when PS-K was given for 5 days in 1 week, or in 22 of 66 mice (33.3%) when PS-K was administered twice a week for 7 weeks. The MSTs of mice with local recurrence were also found to be prolonged as compared with those of mice treated by surgery alone (54.8-67.5 days vs 49.8 days). The MSTs of mice without tumor recurrence were also prolonged significantly (P less than 0.05-0.001) by combinations of PS-K at various times, although most of the mice died of metastatic tumors even in the groups of mice where a combined treatment with PS-K had been administered. The above findings suggest that the administration of PS-K inhibits the growth of recurrent or metastatic tumor cells in autochthonous mice after the surgical removal of the primary tumors.
D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D000818:Animals; D003131:Combined Modality Therapy; D003520:Cyclophosphamide / Q000627:therapeutic use; D005260:Female; D007167:Immunotherapy; D008748:Methylcholanthrene; D051379:Mice; D008810:Mice, Inbred C57BL; D009364:Neoplasm Recurrence, Local; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000401:mortality / Q000628:therapy*; D011509:Proteoglycans / Q000627:therapeutic use*; D013997:Time Factors
D000276:Adjuvants, Immunologic; D011509:Proteoglycans; C010770:polysaccharide-K; D008748:Methylcholanthrene; D003520:Cyclophosphamide