Laparoscopic colon surgery has been performed widely. As a minimal invasive approach, single incision (Embryonic NOTES) colon surgery has been attempted.

However, there are not sufficient evidences for single incision colon surgery in colon cancer.

The investigators are researching the efficacy and safety of single incision laparoscopic sigmoidectomy in sigmoid colon cancer.

After several randomized clinical trials, laparoscopic colon surgery has been performed widely. As a minimal invasive approach, single Incision (Embryonic NOTES) colon surgery has been attempted. Several studies reported the feasibility of single incision colon surgery.However, there are not sufficient evidences for single incision colon surgery, especially in colon cancer.

The investigators are researching the efficacy and safety of single incision laparoscopic sigmoidectomy in sigmoid colon cancer. Harvested numbers of lymph node will be assessed for the efficacy and postoperative morbidity and mortality will be assess for the safety.

Inclusion Criteria:

• Patients should sign a written informed consent
• Age between 18-80
• Patients have sigmoid colon cancer that was proved by pathology
• Adequate bone marrow function Hb ≥ 10g/dl (after treatment for simple iron deficiency anemia) WBC ≥ 3,000/mm3 PLT ≥ 100,000/mm3
• Adequate kidney function Creatinine ≤ 1.5 mg/dl
• No remarkable evidence of heart dysfunction and lung dysfunction

Exclusion Criteria:

• Distant metastasis
• Tumor diameter > 5 cm
• Other organ invasion
• Intestinal obstruction and stent insertion status
• Patient was used steroid
• Patients undergo emergency surgery with multiple symptoms
• Other organ cancer history (except who had radical excision for skin cancer)
• Presence of other serious disease
• Mentally ill patients
• Legally unable to participate in clinical trial
• Lactating or pregnant women
• Patients who will obviously fail to regular follow-up visit or will be off study voluntarily
• Not eligible to participate for other reasons by doctor's decision