胃癌ESD適応拡大病変（未分化型優位）の経過と予後

The Long Term Prognosis of Expanded Indication Lesions of Endoscopic Submucosal Dissection for Undifferetiated Type Early Gastric Cancer

要旨　近年，早期胃癌の内視鏡治療の適応は腫瘍径20mm以下，潰瘍なしの未分化型粘膜内癌にまで臨床研究として拡大されているが，その長期予後は明らかになっていない．今回，ESDを行った未分化型粘膜内癌の長期予後を検討した．109例にESDを行い，治癒切除率は81.7％，観察期間62.6か月（中央値）で原病死3例，他病死11例，5年全生存率，疾患特異的生存率は89.8％，96.9％であった．手術された未分化型適応拡大病変50例とESD治癒切除の89例を比較し，手術の5年全生存率，疾患特異的生存率はともに100％，ESDは90.9％，97.5％で有意差はなかった．未分化型適応拡大病変に対するESDは治療選択のひとつとなりえる．

　Recently, for the purposes of clinical research, the indication for ER（endoscopic resection）in patients with EGC（early gastric cancer）has been expanded to include UD-type（undifferentiated-type）non-ulcerated mucosal cancer of 20mm or less. However, the long-term prognosis in these patients treated with ER remains unclear. In the present study, we investigated the long-term prognosis in patients who underwent ESD（endoscopic submucosal dissection）for UD-type EGC.

　We studied 109 patients who underwent ESD for UD-type EGC. The curative resection rate was 81.7％. The median follow-up observation period was 62.6months. Three patients died of the primary disease, and 11 patients died of another un-related disease. The five-year overall and the disease-specific survival rates were 89.8％ and 96.9％, respectively.

　We compared two groups of patients with EGC that met the expanded indication criteria. Eighty-seven patients had curative resection of EGC through ESD and 50 patients underwent surgery（ER）. In the surgery group, the five-year overall and disease-specific survival rates were 100％. In the ESD group, the five-year overall and disease-specific survival rates were 90.9％and 97.5％, respectively. The differences in survival rates between the groups were not significant.

　The results of the present study show that ESD is an effective treatment for UD-type EGC that meets the recently expanded indication criteria.