Pathways of peritoneal tumour recurrence after abdominal surgical trauma

The peritoneum is the largest and the most complex arranged serous membrane in the body that lines both the intra-abdominal wall and the viscera contained within the peritoneal cavity. It is capable of walling off infections and has several functions such as the ability to synthesise, secrete or absorb. The peritoneum diminishes friction among abdominal viscera, thereby enabling their free movement. With a surface area of some 10,000 cm2 in adults , almost equal to that of the skin, this membrane may be considered among the largest organs in humans. The peritoneal cavity normally contains less than 100 ml of serous fluid that resembles an ultrafiltrate of plasma and contains less than 3 g/dl protein. Taken together the surface area and the functional capacity of the peritoneum, this enables the peritoneal cavity to be used for continuous ambulatory dialysis (CAPO) as well as an internal reservoir during drainage procedures (i.e. ventriculoperitoneal shunts). The peritoneum and the serosal surfaces of organs within the peritoneal cavity are composed of mesothelium and sub-mesothelial connective tissue. Highly differentiated mesothelial cells, resting on a basement membrane, overly the connective tissue. Embedded in this layer are numerous blood vessels and lymphatics. In terms of blood supply per mass, the peritoneum is one of the most richly vascularised organs. Interspersed among the connective tissue are poorly dif

Scavenging of reactive oxygen species leads to diminished peritoneal tumor recurrence

Previously, we demonstrated that RBCs inhibit the recurrence of perioperatively spilled tumor cells. The aim of this study was to identify on which RBC component(s) the inhibitory effect is based. By using a cell-seeding model in rats, the effect of RBC-related antioxidant scavengers [hemoglobin, catalase, 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

Red blood cells inhibit tumour cell adhesion to the peritoneum

Background: Perioperative blood transfusion has been associated with increased tumour recurrence and poor prognosis in colorectal cancer. Blood loss in the peritoneal cavity might be a tumour-promoting factor for local recurrence. The aim of this study was to investigate whether blood in the peritoneal cavity affects local tumour recurrence. Methods: In an established in vivo rat model the effect of 1.5 ml syngeneic whole blood on tumour cell adhesion and tumour growth was investigated. In the same model the effect of 1.5 ml pure red blood cell (RBC) concentrate and 1.5 ml RBC-derived substances on tumour cell adhesion was studied. In an established in vitro model the effect of increasing numbers of RBCs (0-250 x 10 6) on tumour cell adhesion and tumour growth was assessed. Results: Both the presence of blood and RBC concentrate in the peritoneal cavity prevented tumour cell adhesion in vivo (overall P ≤ 0.001 and P ≤ 0.05 respectively), rather than promoting adherence. RBC concentrate and RBC-derived substances had a comparable inhibitory effect on tumour cell adhesion. In in vitro studies RBCs inhibited tumour cell adhesion but not tumour growth. Conclusion: RBC-derived factors prevent tumour cell adhesion to the peritoneum, and consequently tumour recurrence