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 experim ental model. Mice were injected with colonic tumor cells. Local and systemi c effects of pneumoperitoneum were evaluated. Treated mice were randomly as signed to a control group, an open cecectomy group, or a laparoscopic-simul ated cecectomy group. When a tumor inoculum was injected into the peritonea l cavity, the frequency of tumors was not significantly different for mice in the laparoscopic-simulated and open cecectorny groups (60% vs 62%, respe ctively). 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 inject ed subcutaneously, the frequency of tumor nodules and the size and weight o f tumors were not different between the two surgical groups. Laparoscopic-s imulated cecectomy does not appear to adversely effect local factors or fav orably affect systemic factors influencing tumor growth or survival.