Sinusoidal Obstruction Syndrome Promotes Liver Metastatic Seeding of Colorectal Cancer Cells in a Rat Model

Background/Aim: Sinusoidal obstruction syndrome (SOS) after neoadjuvant chemotherapy with oxaliplatin for colorectal liver metastases (CRLM) has been reported to lead to early recurrence. This study investigated the effects of SOS on the development of CRLM in a rat model. Materials and Methods: RCN-H4 cells were injected into the spleen or liver of ten monocrotaline-treated (SOS group) and ten untreated (control group) rats. The number and size of liver tumors were compared between the groups. Results: The number of liver tumors in the splenic RCN-H4 injection model was significantly higher in the SOS group than in the control group (332±213 vs. 16±5, p=0.029); however, the largest tumor diameter in the hepatic model was similar between groups (6.2±1.8 vs. 6.4±2.4 mm, p=0.87). Conclusion: SOS promotes CRLM development by splenic RCN-H4 cell injection. This might be due to the higher incidence of cancer cell implantation into the liver.