The purpose of this study is to evaluate the of international standard operation, mesorectal excision (ME alone) compared to Japanese standard operation, ME with lateral lymph node dissection for clinical stage II, III lower rectal cancer

Total mesorectal excision (TME) or mesorectal excision (ME) with lateral lymph node dissection for advanced rectal cancer is widely performed in Japan. In other countries, TME or ME without lateral lymph node dissection is the standard. In order to determine which is the better rectal cancer surgery, relapse-free survivals of these are compared as the primary endpoint.

Inclusion Criteria:

Preoperative criteria:

1. Histologically confirmed adenocarcinoma

2. Clinical stage II or III

3. Preoperative findings:

   • Main lesion of the tumor is located at the rectum
   • Lower tumor margin is below the peritoneal reflection
   • No extramesorectal lymph node swelling (Shorter diameter is less than 10 mm)
   • No invasion to other organ (s)

4. Patient age is more than 20 and less than 75

5. PS: 0, 1

6. No past history of chemotherapy, pelvic surgery or radiation

7. Written informed consent

   Operative criteria:

8. Mesorectal excision is performed

9. Operative findings:

   • Main lesion of the tumor is located at the rectum
   • Lower tumor margin is below the peritoneal reflection

10. R0 after resection

Exclusion Criteria:

1. Multiple cancer patients
2. Pregnant patients
3. Psychological disorder
4. Steroid administration
5. Cardiac infarction within six months
6. Severe pulmonary emphysema and pulmonary fibrosis
7. Doctor's decision for exclusion