Scavenging of reactive oxygen species leads to diminished peritoneal tumorrecurrence

Previously, we demonstrated that RBCs inhibit the recurrence of perioperati vely spilled tumor cells. The aim of this study was to identify on which RB C component(s) the inhibitory effect is based, by using a cell-seeding mode l in rats, the effect of RBC-related antioxidant scavengers [hemoglobin, ca talase, and superoxide dismutase (SOD)] on peritoneal tumor recurrence was investigated. i.p. injection of hemoglobin caused 45% more tumor load (P < 0.0001), At least 40% inhibition of tumor recurrence was achieved with the use of catalase or SOD (P < 0.05), Combining SOD and catalase did not lead to additional inhibition of tumor recurrence. Inhibition of the overwhelmin g oxidative potential after surgical peritoneal trauma with the use of scav engers may lead to interesting new approaches for diminishing peritoneal tu mor recurrence.