1. 1 Motohiko Kato, Tsutomu Nishida, Katsumi Yamamoto, Shiro Hayashi, Shinji Kitamura, Takamasa,Yabuta, Toshiyuki Yoshio, Takeshi Nakamura, Masato Komori,6 Naoki Kawai, Akihiro Nishihara, Fumihiko Nakanishi, Masanori Nakahara, Hideharu Ogiyama, Kazuo Kinoshita, Takuya Yamada,Hideki Iijima, Masahiko Tsujii, Tetsuo Takehara Gut 2012;0:1–8. doi:10.1136/gutjnl-2011-301647 F1 김혁 / Prof 장재영

2. Introduction Gastric cancer : 870 000 new cases and 650 000 deaths annually Early gastric cancer, LN(-) –the 5-year gastric cancer-specific survival rate is 99% in Japan Endoscopic Resection (ER) : Endoscopic Submucosal Dissection (ESD) –preserves the entire stomach and the patient’s quality of life (QoL) –Gastric cancer generally arises from H pylori associated chronic gastritis –Preserving the stomach contributes to maintaining postoperative QoL but could increase the risk of multiple cancer development from the remnant gastric mucosa –Follow-up is important for detecting multiple cancers after ER 2

3. Aim To elucidate the patterns of multiple cancer development from remnant gastric mucosa To determine whether scheduled endoscopic surveillance can control multiple cancers after successful ER 3

4. PATIENTS AND METHODS 4 1.Multicenter retrospective cohort study 2.12 hospitals participating in the Osaka University ESD Study Group 3.Approved by the Osaka University institutional review board 1 university hospital, 5 secondary care hospitals and 6 tertiary care hospitals

5. PATIENTS AND METHODS 5 Underwent curative ESD : 1999.4 ~ 2010.12 Three groups proposed by Gotoda –Guideline group mucosal differentiated cancer, largest diameter <20 mm –Expanded guideline group differentiated cancer, largest diameter >20 mm differentiated cancer with ulceration, largest diameter <30 mm differentiated cancer, largest diameter <30 mm, submucosal invasion <500 μm –Non-curative group did not meet these criteria

6. PATIENTS AND METHODS 6 Multiple gastric cancer development –Synchronous cancer (within 1 year) Concomitant cancer : diagnosed before the initial ESD Missed cancer : being detected within 1 year but not detected at the time of the initial ESD –Metachronous cancer (after 1 year)

7. PATIENTS AND METHODS 7 Investigated the methods preoperative screening by questionnaire How often was each endoscopic modality used for preopertive screening? How much experience does an endoscopist need to be allowed to perform preoperative screening in your hospital?

8. PATIENTS AND METHODS 8 First f/u EGD within 1mon : 30% First f/u EGD within 3mon : 41% First f/u EGD within 6mon : 100% Surveillance EGD : every 6–12 mon Abdominal CT : by final pathological diagnosis Follow-up protocols

9. RESULTS 9 Prognosis-chasing rate : 97.9% Mean observation period : 26.8 months

10. RESULTS 10 Not significantly differ between patients with and without multiple cancers -Location -Size -Macroscopic type -Histological type -Invasion depth -Guideline classification 13.9%

11. RESULTS 11 19% Synchronous cancer -21 missed cancers - Median time to detection : 6.3 months -The mean diameter : 21mm -Upper third of the Stomach : 33% -Lesser curvature or posterior wall : 81% -Submucosal invasion : 3 -Muscularis propria invasion : 1

12. RESULTS 12 3.7% 16% Metachronous cancer - increased linearly

13. RESULTS 13 Successful H pylori eradication : no difference in the cumulative incidence rate of multiple cancers Because….. -Study design -Observation period

14. RESULTS 14 Treatment-related Deaths : 0 % The 3-year overall survival rate : 96.8% Disease-specific survival rate : 100% 96.8%

15. RESULTS 15 Surveillance EGD -at least once a year after the ESD hospitals Massively invading cancer -more than 1 year after ESD occurred in only one Based on these findings, we recommend that annual surveillance be performed

16. Conclusions This is the first multicenter study of long-term outcomes after ESD for EGC One of the largest to date Incidence of synchronous cancer rate : 9% –19% of synchronous cancers were missed Incidence of metachronous cancer : increased linearly With an annual follow-up examination, almost all multiple lesions could be cured by ER. 16