The purpose of this study is to evaluate the midline extraction incision in patients with colon cancer. A prospective randomized controlled trial is conducted to compare midline extraction incision with off-midline extraction incision.

Laparoscopic colon surgery is less invasive and more cosmetic than open surgery. But the extraction-site incision is 4 to 5 cm, and it is the largest and most painful incision in laparoscopic colon surgery. The purpose of this study is to evaluate the midline extraction incision in patients with colon cancer. A prospective randomized controlled trial is conducted to compare midline extraction incision with off-midline extraction incision. The investigators hypothesize that the use of the midline extraction incision in laparoscopic colon surgery will result in more cosmetic effect and better quality of life compared to the off-midline extraction incision.

Inclusion Criteria:

• Tumor size is less than 5cm
• No history of laparotomy
• No bowel obstruction by tumor

Exclusion Criteria:

• Patients who can't respond to medical question
• Patients who receive steroids or insulin therapy
• Uncontrolled DM
• Severe respiratory failure(HOT)