Laparoscopic Surgery and Cancer Metastasis

Despite the wide spread use of laparoscopic techniques for malignant tumors, the oncological merits have not yet been fully determined. In this article, the author has reviewed reports of the therapeutic results of laparoscopically treated colorectal cancer and the literature for basic science experiments relating to CO2 pneumoperitoneum and the mechanisms of spread and metastasis of cancers. Since the introduction of laparoscopic surgery for colorectal cancer, port site metastasis has been noted as a phenomenon peculiar to laparoscopic surgery. Although the incidence of port site metastasis is decreasing with the technical advancement of laparoscopy, there are still problems that may not be solved with technology alone. Most of the currently reported results of prospective nonrandomized studies comparing laparoscopic and conventional colorectal resection did not show any difference in the prognosis of patients. Numerous animal experiments have been undertaken to clarify the oncological effects of laparoscopic surgery, yet many have conflicting results. In order to evaluate the animal experiments related to laparoscopic surgery (pneumoperitoneum), this paper focuses on the duration and pressure of pneumoperitoneum as well as whether the clinical conditions are properly recreated. This review of the literature concludes that the results of large scale prospective randomized controlled studies with carefully selected indications are necessary before laparoscopic surgery for malignant tumors such as colorectal cancer can be safely popularized.