Effect of low molecular weight heparin on intra-abdominal metastasis in a laparoscopic experimental study

Background and aims. Metastatization, adhesion, invasion, and growth of tumor cells involve a cascade of complex phenomena which may be affected. We investigated the effect of a low molecular weight heparin, reviparin, on intra-abdominal tumor growth and intra-abdominal metastasis in rats undergoing laparoscopy. Methods. CC531 adenocarcinoma cells (5x10(6) cells/ml) were administered intraperitoneally to 150 Wistar Albino Glaxo rats, with 15 groups of animals each. During laparoscopy 1 ml saline containing 0.0, 0.5, 2.0,; 4.0, and 10 mg reviparin/kg b.w. was introduced intraperitoneally (i.p.), daily subcutaneously (s.c.), or combined. After 21 days the animals were killed and underwent autopsy, and the tumor weight and the number of metastases on the liver surface were determined.<LF>Results. Tumor weight was significantly reduced by 4.0 and 10.0 mg/kg b.w. but not by 0.5 or 2.0 mg/kg b.w. compared to controls. Decreased metastatization was observed in all treated groups. These effects were most pronounced after the s.c. or combined i.p. and s.c. administration, whereas after a sole i.p. administration only the highest dose of 10 mg/kg b.w. induced a significant inhibition of tumor growth. Conclusion. Low molecular weight heparin given s.c. or in combination of i.p. lavage and s.c. injections significantly inhibits intra-abdominal tumor growth and intraperitoneal metastasis of CC531 adenocarcinoma cells in rats undergoing laparoscopy. This may offer additional therapeutic options for patients undergoing laparoscopic and also open cancer surgery.