The number and level of positive micrometastatic lymph nodes was significantly correlated with postoperative recurrence of histologically determined Dukes' B colorectal cancer. This parameter is a useful prognostic indicator in histologically node-negative colorectal cancer and is helpful in planning adjuvant chemotherapy.

Morphologic peritoneal alterations after pneumoperitoneum differed from those after laparotomy and were influenced by the type of gas, amount of pressure, and duration of insufflation. These peritoneal changes after pneumoperitoneum may be associated with a specific intraperitoneal tumor spread after laparoscopic cancer surgery.

Free cancer cells appear to attach to the injured port sites immediately after CO2 pneumoperitoneum, and these are associated with the development of port-site metastasis after laparoscopic cancer surgery.

Under CO2 pneumoperitoneum, exogenous hyaluronic acid increased the frequency and weight of port site metastasis in a murine model. Hyaluronic acid secreted from mesothelial cells may be associated with the formation of port site metastasis after laparoscopic surgery for cancer under pneumoperitoneum.

In a murine model, the intraperitoneal concentration of hyaluronic acid was significantly increased after CO2 pneumoperitoneum, and the increase was more evident than that after laparotomy. Increased hyaluronic acid during pneumoperitoneum may be associated with port-site metastasis after laparoscopic cancer surgery.