Masao Yoshida1, Kohei Takizawa2, Noriaki Hasuike3, Hiroyuki Ono1, Narikazu Boku4, Tomohiro Kadota5, Junki Mizusawa6, Ichiro Oda7, Naohiro Yoshida8, Yusuke Horiuchi9, Kingo Hirasawa10, Yoshinori Morita11, Yoshinobu Yamamoto12, Manabu Muto13. 1. Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan. 2. Department of Gastroenterology and Endoscopy, Sapporo Kinentou hospital, Hokkaido, Japan. 3. Hasuike Clinic, Hyogo, Japan. 4. Department of Oncology and General Medicine, IMSUT Hospital, Institute of Medical Science, University of Tokyo, Tokyo, Japan. 5. Department of Gastroenterology and Endoscopy, National Cancer Center Hospital East, Chiba, Japan. 6. Japan Clinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan. 7. Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan; Department of Internal Medicine, Kawasaki Rinko General Hospital, Kanagawa, Japan. 8. Department of Gastroenterology, Ishikawa Prefectural Central Hospital, Ishikawa, Japan. 9. Department of Gastroenterology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan. 10. Division of Endoscopy, Yokohama City University Medical Center, Kanagawa, Japan. 11. Department of Gastroenterology, Kobe University School of Medicine, Hyogo, Japan; Department of Gastroenterology, Kobe University International Clinical Cancer Research Center, Hyogo, Japan. 12. Department of Gastroenterological Oncology, Hyogo Cancer Center, Hyogo, Japan. 13. Department of Therapeutic Oncology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Abstract
BACKGROUND AND AIMS: Endoscopic resection (ER) for early gastric cancer (EGC) can preserve the stomach; however, the remaining stomach can develop second gastric cancer. Few reports have prospectively investigated the incidence and treatment outcomes of second gastric cancer. METHODS: This post-hoc analysis used the dataset of the single-arm confirmatory trial, JCOG0607. The key inclusion criteria for JCOG0607 were solitary differentiated-type EGC and no previous gastrectomy or endoscopic treatment for EGC. Three hundred seventeen patients who underwent curative ER were included in this study. Surveillance endoscopy was performed 1 to 3 months after the initial ER and subsequently annually for at least 5 years. A lesion detected ≤1 year and >1 year after the initial ER was defined as overlooked gastric cancer (OGC) and metachronous gastric cancer (MGC), respectively. RESULTS: During a median follow-up period of 6.0 years (interquartile range, 5.1-7.0), 30 OGCs and 61 MGCs were detected in 24 and 48 patients, respectively. The cumulative incidence of OGC at 1 year and MGC at 5 years was 7.6% and 12.7%, respectively. ER and gastrectomy were performed in 85 lesions and 6 lesions, respectively. Pathologic evaluation showed 78 mucosal cancers, 12 submucosal cancers, and 1 advanced cancer. Eventually, 28 OGCs and 52 MGCs fulfilled the pathologic criteria for curative ER. CONCLUSIONS: Our study was the first to reveal the actual incidence of second gastric cancer after curative ER for differentiated-type gastric cancer. Most lesions could be treated with ER. Continuous endoscopic surveillance after curative ER is important to detect second gastric cancer.
BACKGROUND AND AIMS: Endoscopic resection (ER) for early gastric cancer (EGC) can preserve the stomach; however, the remaining stomach can develop second gastric cancer. Few reports have prospectively investigated the incidence and treatment outcomes of second gastric cancer. METHODS: This post-hoc analysis used the dataset of the single-arm confirmatory trial, JCOG0607. The key inclusion criteria for JCOG0607 were solitary differentiated-type EGC and no previous gastrectomy or endoscopic treatment for EGC. Three hundred seventeen patients who underwent curative ER were included in this study. Surveillance endoscopy was performed 1 to 3 months after the initial ER and subsequently annually for at least 5 years. A lesion detected ≤1 year and >1 year after the initial ER was defined as overlooked gastric cancer (OGC) and metachronous gastric cancer (MGC), respectively. RESULTS: During a median follow-up period of 6.0 years (interquartile range, 5.1-7.0), 30 OGCs and 61 MGCs were detected in 24 and 48 patients, respectively. The cumulative incidence of OGC at 1 year and MGC at 5 years was 7.6% and 12.7%, respectively. ER and gastrectomy were performed in 85 lesions and 6 lesions, respectively. Pathologic evaluation showed 78 mucosal cancers, 12 submucosal cancers, and 1 advanced cancer. Eventually, 28 OGCs and 52 MGCs fulfilled the pathologic criteria for curative ER. CONCLUSIONS: Our study was the first to reveal the actual incidence of second gastric cancer after curative ER for differentiated-type gastric cancer. Most lesions could be treated with ER. Continuous endoscopic surveillance after curative ER is important to detect second gastric cancer.