An evidence-based medicine approach to the laparoscopic treatment of colorectal cancer.

During the 1990s, laparoscopic resection was established as a treatment for gastrointestinal malignant tumors.　A number of randomized controlled trials comparing laparoscopic-assisted colorectal surgery with conventional open colorectal surgery for colon cancer have been conducted.　These trials have shown short-term benefits, and the vast majority demonstrated no significant difference in long-term outcomes.　Laparoscopic-assisted colorectal surgery is widely performed for the treatment of colon cancer, whereas laparoscopic-assisted colorectal surgery for rectal cancer is less commonly performed.　In recent years, there have been an increasing number of reports of laparoscopic-assisted colorectal surgery for rectal cancer, where improving short-term outcomes was shown, but no definitive effect on long-term survival has been shown to date.　Randomized controlled trials focusing on long-term survival are currently ongoing.