Introduction: Local recurrence and peritoneal dissemination is common after intentionally curative resection of colorectal carcinoma. It is not yet clear which mechanisms stimulate post-operative intra-abdominal tumor development. Enhanced adhesion or growth of tumor cells and/or post-operative immuno suppression may influence tumor recurrence. Aims of the study: In the present study, we evaluated effects of local and remote surgery on intra-abdominal tumor development. Materials and Methods: A standardized intra-abdominal trauma was inflicted by rubbing both uterus horns in laparotomy groups, while a dorsolateral thoracotomy was performed in thoracotomy groups (on day -1, 0, or +3). To induce tumor development rats were injected intra-peritoneally with the coloncarcinoma cell line CC531s on day 0 and evaluated after 21 days. Results: Rats undergoing laparotomy and injection on day 0 showed significantly higher tumorload than control rats (195 ± 20 vs. 47 ± 29, P < 0.001). When a laparotomy was performed, the day before tumor inoculation even higher tumorload was seen (245 ± 37 vs. 195 ± 20, P < 0.01). Strikingly, performing a thoracotomy on the day before or on the same day as tumor inoculation resulted in enhanced tumorload compared to controls as well (135 ± 84 vs. 47 ± 29; P < 0.001 and 88 ± 38 vs. 47 ± 29; P < 0.02, respectively). Either laparotomy or thoracotomy 3 days after tumor cell inoculation did not affect growth of pre-existing tumor cell clusters. Conclusions: The (post) surgical intra-peritoneal microenvironment enhances successful implantation of spilled tumor cells, whereas growth of adhered tumor cell clusters is not affected. The inflammatory response as a result of remote surgery promotes successful tumor development as well.

Growth, Rat model, Surgical trauma, Tumor cell adhesion,
Journal of Surgical Oncology
Department of Surgery

ten Raa, S, Oosterling, S.J, van der Kaaij, N.P, van den Tol, M.P, Beelen, R.H.J, Meijer, S, … Jeekel, J. (2005). Surgery promotes implantation of disseminated tumor cells, but does not increase growth of tumor cell clusters. Journal of Surgical Oncology, 92(2), 124–129. doi:10.1002/jso.20273