Seiichiro Abe1, Kohei Takizawa2, Ichiro Oda3, Junki Mizusawa4, Tomohiro Kadota4, Hiroyuki Ono2, Noriaki Hasuike5, Tomonori Yano6, Yoshinobu Yamamoto7, Yusuke Horiuchi8, Shinji Nagata9, Takaki Yoshikawa10, Masanori Terashima11, Manabu Muto12. 1. Endoscopy Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan. seabe@ncc.go.jp. 2. Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan. 3. Endoscopy Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan. 4. Japan Clinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan. 5. Hasuike Clinic, Kobe, Japan. 6. Department of Gastroenterology and Endoscopy, National Cancer Center Hospital East, Kashiwa, Japan. 7. Department of Gastroenterology, Hyogo Cancer Center, Hyogo, Japan. 8. Department of Gastroenterology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan. 9. Department of Gastroenterology, Hiroshima City Asa Citizens Hospital, Hiroshima, Japan. 10. Gastric Surgery Division, National Cancer Center Hospital, Tokyo, Japan. 11. Division of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan. 12. Department of Therapeutic Oncology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Abstract
BACKGROUND AND AIMS: A drawback of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is the development of metachronous gastric cancer (MGC). While MGC after ESD for differentiated-type (D-) EGC was well understood, little is known about MGC occurring after ESD for undifferentiated-type (UD-) EGC, because ESD had not been indicated. We evaluated the incidence and treatment outcomes of MGC after ESD of UD-EGC. METHODS: This study is a post hoc analysis of JCOG1009/1010, a multicenter trial to evaluate the efficacy and safety of ESD for UD-EGC. The patients who underwent curative ESD of index solitary UD-EGC were analyzed. Surveillance endoscopy was performed biannually for the first 3 years and thereafter annually. We assessed the time to MGC occurrence after ESD, lesion characteristics, and treatment outcomes of MGC. Time to MGC occurrence was estimated by cumulative incidence function, with death and total gastrectomy as competing risks. RESULTS: A total of 198 patients were included in this study. During a median follow-up period of 5.8 years, 4 patients (2%) developed MGC. Median time to MGC occurrence was 4.5 years (range: 3.1-5.4). Five-year cumulative incidence of MGC was 1.0% (95% CI: 0.2-3.3%). Two MGCs were histologically D-EGC, and the remaining two were UD-EGC. The median tumor size of MGCs was 1.0 cm (range: 0.7-1.7), and the depth of invasion (M/SM1/SM2) was 2/1/1, respectively. Three patients achieved curative resection with repeated ESD. CONCLUSIONS: MGC does not occur commonly after curative ESD of UD-EGC, and repeated ESD could contribute to stomach preservation.
BACKGROUND AND AIMS: A drawback of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is the development of metachronous gastric cancer (MGC). While MGC after ESD for differentiated-type (D-) EGC was well understood, little is known about MGC occurring after ESD for undifferentiated-type (UD-) EGC, because ESD had not been indicated. We evaluated the incidence and treatment outcomes of MGC after ESD of UD-EGC. METHODS: This study is a post hoc analysis of JCOG1009/1010, a multicenter trial to evaluate the efficacy and safety of ESD for UD-EGC. The patients who underwent curative ESD of index solitary UD-EGC were analyzed. Surveillance endoscopy was performed biannually for the first 3 years and thereafter annually. We assessed the time to MGC occurrence after ESD, lesion characteristics, and treatment outcomes of MGC. Time to MGC occurrence was estimated by cumulative incidence function, with death and total gastrectomy as competing risks. RESULTS: A total of 198 patients were included in this study. During a median follow-up period of 5.8 years, 4 patients (2%) developed MGC. Median time to MGC occurrence was 4.5 years (range: 3.1-5.4). Five-year cumulative incidence of MGC was 1.0% (95% CI: 0.2-3.3%). Two MGCs were histologically D-EGC, and the remaining two were UD-EGC. The median tumor size of MGCs was 1.0 cm (range: 0.7-1.7), and the depth of invasion (M/SM1/SM2) was 2/1/1, respectively. Three patients achieved curative resection with repeated ESD. CONCLUSIONS: MGC does not occur commonly after curative ESD of UD-EGC, and repeated ESD could contribute to stomach preservation.