Laparoscopic sentinel lymph node biopsy and stomach preserving surgery in early gastric cancer is less invasive method which can increase quality of life. For last two years, multicenter quality control study (Phase II) has been performed in Korea and tolerable results were observed. Based on these results, multicenter phase III trial is required to validate the clinical role of laparoscopic sentinel lymph node biopsy.

The final analyses include the modified intention to treatment analysis (full analysis set) and Per Protocol analysis (including patients who underwent assigned surgery without agreement withdrawal).

1. Injection of tracer and sentinel basin dissection

   • Tracer: Tc 99m HSA (Human serum albumin, 2ml, 0.1mCi/ml) + ICG (indocyanine green, 2ml, 5mg/ml)
   • Endoscopic injection of tracer on 4 sites around gastric cancer
   • Identification of sentinel basin using laparoscopic probe (Neoprobe)
   • Laparoscopic sentinel basin dissection and identification of sentinel node at back table

2. Surgical considerations

   • If positive sentinel nodes were diagnosed in frozen section, conventional gastrectomy is performed.
   • If micrometastasis or isolate tumor cells in sentinel basin lymph nodes were diagnosed in the permanent pathology, re-operation of conventional gastrectomy is not performed.
   • However, re-operation of converntional gastrectomy should be performed in case of macrometastasis, deep and lateral margin positive, more than pT2 lesion in the permanent pathology.

3. H.pylori eradication - There was no clear evidence that H.pylori eradication reduced development of metachronous gastric cancer. H.pylori eradication was planned to perform according to physician's decision or patient's need. However, recently, the effect of H.pylori eradication in development of metachronous gastric cancer was published in NEJM (Choi et al. 2018). Therefore, from now on, H. pylori eradication will be recommended to enrolled patients with H.pylori.

Inclusion Criteria:

• single lesion of adenocarcinoma in preoperative endoscopic biopsy
• clinical stage T1N0 in the preoperative evaluation of endoscopy and computed tomography
• tumor size: less than 3cm
• location: 2cm far from the pylorus or cardia
• aged 20 to 80
• ECOG 0 or 1
• patient who signed the agreement
• patient who is suspected to underwent laparoscopy assisted gastrectomy

Exclusion Criteria:

• indication of endoscopic submucosal resection
• inoperable due to poor cardiac, pulmonary function
• pregnant
• having allergic reaction, previous upper abdominal surgery except laparoscopic cholecystectomy, previous radiation therapy to upper abdomen
• diagnosed as malignancy within 5 years except carcinoma in situ of cervix cancer and thyroid cancer

We will discuss this topic in the research meeting later.