In oncological aspect, D1+ lymph node dissection would be enough for early stage gastric cancer in advanced gastric cancer (stage IB/IIA/IIB ).

■ Background of Hypothesis A. JCOG (Japanese Clinical Oncology Group) 9501 Study

: Addition of aorta lymph node dissection to D2 lymph node dissection does not increase survival rate.

Wide range of operation is not always the best treatment. If invasion rate can be kept as minimal as possible while maintaining survival rate, it can lead to more secure operation while also reducing the frequency of complication after the surgery. 20 It may be advantageous for patients in terms of operation time, cost, and quality of life.

B. COACT 1001 study A previous study which compared the feasibility of lymph node dissection in open surgery and lapraroscopic surgery for advanced gastric cancer.

11p, 12a lymph node (D2) resection rate: 79.2% and 88.8% respectively in all advance gastric cancer.

11p, 12a lymph node (D2) metastasis rate: 1.9% and 2.9% respectively. Subgroup analysis 11p, 12a lymph node resection in cStage IB/IIA: 74.5-80.0% and 86.7-96.1% respectively. : 0% metastasis rate for both.

lymph node dissection in cStage IIB/IIIA: 81.1-82.3% and 87.5-89.2% respectively.: metastasis rates are 2.1% and 2.4-12.1% respectively.

Application: 11p and 12a lymph nodes, which belong in D2 lymph nodes, need to be resected in advance gastric cancer in IIB stage or higher. However, in earlier stages of advance gastric cancer, the probability of metastasis is very low; therefore, resection of D1+ lymph nodes, excluding 11p and 12a, is enough.

Inclusion Criteria :

• Histologically proven primary gastric adenocarcinoma

• T1N1, T2N0, T2N1, T3N0, T3N1 by CT scan (AJCC 7th classification) and intraoperative surgical staging prior to resectional procedure

• Location of primary tumor; antrum, or angle, lower body or mid body of the stomach

• No evidence of other distant metastasis

• Aged ≥ 20 year old

• Performance status (PS) of 0 or 1 on Eastern Cooperative Oncology Group (ECOG) scale

• No prior treatment of chemotherapy or radiation therapy against any other malignancies, and no prior treatment for gastric cancer including endoscopic mucosal resection

• Adequate organ functions defined as indicated below:

  • WBC 3000/mm3 - 12,000/mm3
  • >serum Hemoglobin 8.0 g/dl
  • > serum Platelet 100 000/mm3
  • < serum AST 100 IU/l
  • \