Topical Treatment With Oxaliplatin for the Prevention of Port-Site Metastases in Laparoscopic Surgery for Colorectal Cancer

BACKGROUND: The development of port-site metastases following laparoscopic resection of various malignancies continues to be a disturbing issue for laparoscopic surgeons. Previous studies revealed promising results with oxaliplatin, a third-generation platinum compound, as a first-line treatment in advanced colorectal cancer. This study evaluates the effect of topical application of oxaliplatin on the development of port-site metastases in an experimental murine model. METHODS: Nineteen female BDIX rats (immunocompe-tent, 6 weeks old) underwent a sham laparoscopic operation after 1x10(7) viable rat colon carcinoma viable cells (LMCR) had been injected into their peritoneal cavities. Three trocars (1 central camera port and 2 additional lateral ports) were introduced into the abdomen, and a pneumoperitoneum was created with carbon dioxide. Ten minutes after LMCR, cells were injected into the peritoneal cavity, the 2 lateral trocars were removed and carbon dioxide insufflation was maintained for an additional 5 minutes to allow for tumor cell seeding. Oxaliplatin (0.198 mg/kg) was then topically applied to 1 trocar site intramuscularly, while the other site was left untreated. One week later, the animals were euthanized, and the port sites were histologically examined for evidence of metastases. RESULTS: The rate of tumor implantation at the muscle layer in control sites was 68% (13/19) compared with 37% (7/19) at oxaliplatin-treated sites (P=0.1). Also, no significant differences were detected in port-site metastasis rates in other untreated layers of the abdominal wall. CONCLUSION: Intramuscular topical application of oxaliplatin may not decrease the incidence of port-site metastasis in a syngeneic animal model of colon cancer. Nevertheless, we can see the tendency of declination. Further studies are needed to better determine its possible therapeutic role in high-risk humans undergoing laparoscopic resection of colorectal malignancies.