title: Possible effect of pneumoperitoneum on the spreading of colon cancer tumor cells.
abstract: OBJECTIVE
  By using a murine hepatic metastatic model, we tried to investigate the possible influence of gas insufflation in colon cancer cells spreading from the portal system to the liver.
  
  
  METHODS
  After transducing the human placental ALP gene into murine colon cancer cell line CT26, we successfully selected a clone of CT26/DAP that would yield a specific color following histochemical staining. Fifty mice were assigned into two groups, receiving either an intrasplenic injection of 10(6) CT26/DAP cells alone or the cells followed by intra-abdominal helium insufflation with the pressure of 15 cm H2O for ten minutes. Five mice in each group were used to observe their survival and the other mice were killed at four different time periods: 10 minutes, 24 hours, 48 hours, and 72 hours following cell injection. The livers and spleens were removed for histochemical staining. By counting the numbers of specific dark reddish spots of CT26/DAP cells, we could estimate the number of tumor cells on the hepatic surface.
  
  
  RESULTS
  At the very beginning following tumor cell injection, we found a significantly greater number of tumor cells on the hepatic surface in mice with gas insufflation (6354 +/- 1072 vs. 2133 +/- 223, respectively; P = 0.012). But the difference of these two groups became smaller and smaller as time went by. The number of tumor cells on the hepatic surface would reach the lowest level at postoperative 48 hours, and the tumor foci then began to grow both in size and number. The above patterns of dynamic change in tumor cell distribution were similar in mice both with and without gas insufflation. Average survival was slightly shorter in mice with gas insufflation, but the difference was not statistically significant.
  
  
  CONCLUSIONS
  Pneumoperitoneum caused by gas insufflation may increase tumor cell spread from the portal system to the liver at the very beginning stage; however, there was no significant difference in long-term survival between mice with and without gas insufflation in this murine animal model.
authors.affiliation: Division of Colorectal Surgery, Veterans General Hospital-Taipei, College of Medicine, National Yang-Ming University, Taiwan.
authors.forename: W S
authors.initials: WS
authors.lastname: Chen
authors.forename: W
authors.initials: W
authors.lastname: Lin
authors.forename: Y R
authors.initials: YR
authors.lastname: Kou
authors.forename: H S
authors.initials: HS
authors.lastname: Kuo
authors.forename: H
authors.initials: H
authors.lastname: Hsu
authors.forename: W K
authors.initials: WK
authors.lastname: Yang
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000556:secondary; D000469:Alkaline Phosphatase / Q000235:genetics; D000818:Animals; D002452:Cell Count; D003110:Colonic Neoplasms / Q000473:pathology*; D004396:Coloring Agents; D004195:Disease Models, Animal; D005260:Female; D006371:Helium; D006801:Humans; D007267:Injections; D007327:Insufflation / Q000009:adverse effects; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000556:secondary*; D051379:Mice; D008807:Mice, Inbred BALB C; D009366:Neoplasm Seeding; D009368:Neoplasm Transplantation; D010920:Placenta / Q000201:enzymology; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects*; D011168:Portal System / Q000473:pathology; D013154:Spleen; D015996:Survival Rate; D013997:Time Factors; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D004396:Coloring Agents; D006371:Helium; D000469:Alkaline Phosphatase