Prevention of Peritoneal Free (Ascites) Tumor Cell Growth and Implantation by Pretreatment with Radioactive Yttrium. ∗

Abstract

Summary and conclusions

(1) Doses of 0.25 mc of radioactive yttrium phosphate (Y⁹⁰PO₄) were injected into peritoneal cavity of Albino mice immediately following administration of 2 ml of 0.85% NaCl solution; on 3rd to 4th day 10⁵ cells of Krebs-2 Ascites Tumor were inoculated by same route into pre-treated animals and normal controls; their accumulated fluid was withdrawn after 3 or 4 days for estimate of its volume, tumor cell counts and smears; they were sacrificed for autopsies 1 or 2 days later. (2) Amount of ascitic fluid and extent of implant growth were considerably reduced in pretreated animals as compared with controls; free tumor cells in the fluid appeared enlarged, altered (distorted mitoses) and less viable, after transfer into new mice, than in controls; decrease of their concentration in the fluid was not as rapid and extensive as in animals treated with an isotope after inoculation in previous experiments. (3) Cell destruction was increased by injection of 0.1 mc into pretreated mice. (4) It was concluded that pretreatment with radioactive yttrium increased resistance of the peritoneum to invasion with tumor cells, thus decreasing implantation of these cells and exudation of the fluid. (5) It was presumed that the principle of this method may be eventually applied for prevention of “transcoelomic metastases” from some abdominal tumors, before or after their removal.