Goal: The aim of the study was to evaluate the in vitro cytototoxicity of diluted povidone iodine on colon cancer cells and its in vivo antitumoral effect in a model of peritoneal carcinomatosis in the rat.
Methods: Cell cytotoxicity of a povidone iodine diluted solution was assessed, in vitro, on rat colon cancer cells (DHD/K12/PROb) and human colon cancer cells (HT29). The antitumoral effect of diluted povidone iodine washing was measured in BDIX rats after the intraperitoneal inoculation of 10(6) DHD/K12/PROb cells. Results were compared to an abdominal washing within a 9 g/l salinel solution. In one experiment, peritoneal scars and a colocolic anastomosis were performed after the injection of cancer cells.
Results: A short 10 min incubation of human and rat colon cancer cells with diluted povidone iodine resulted in a complete cell killing. In animals, a peritoneal washing with 1% diluted povidone iodine completely inhibited the tumor growth in parietal peritoneum. However, development of peritoneal tumor nodules was not inhibited in the omentum, in scarified peritoneum or in intestinal anastomosis.
Conclusions: Despite its high in vitro efficacy, diluted povidone iodine has an incomplete effect in the prevention of peritoneal carcinomatosis, with only a partial inhibition in scarred peritoneum epiploïc area and intestinal anastomosis. In contrary, it procures a complete inhibition of tumor growth in normal peritoneum.