Effects of laparoscopy on tumor growth.

Laparoscopic resections of colon cancer may affect survival. To address the effects of pneumoperitoneum on tumor cell biology, we developed an experimental model. Mice were injected with colonic tumor cells. Local and systemic effects of pneumoperitoneum were evaluated. Treated mice were randomly assigned to a control group, an open cecectomy group, or a laparoscopic-simulated cecectomy group. When a tumor inoculum was injected into the peritoneal cavity, the frequency of tumors was not significantly different for mice in the laparoscopic-simulated and open cecectomy groups (60% vs 62%, respectively). There was no significant difference in survival time between the laparoscopic-simulated and open cecectomy groups, with median survivals of 24 days versus 22 days, respectively. Finally, when tumor cells were injected subcutaneously, the frequency of tumor nodules and the size and weight of tumors were not different between the two surgical groups. Laparoscopic-simulated cecectomy does not appear to adversely effect local factors or favorably affect systemic factors influencing tumor growth or survival.