早期胃癌ESD後の長期経過の検討

Clinical Outcome of ESD for Early Gastric Cancer

要旨　ESDは早期胃癌に対してより大きな病変を一括切除できる点において有益な治療法である．しかし，その適応を誤り不完全に切除された場合には生命予後を大きく左右する危険性を含んでいる．1999年1月から2002年8月までに国立がんセンター中央病院にて術前適応を満たし，ESDが施行された671病変588症例を対象に根治度と長期経過の検討を行った．対象病変中，525病変（78.2％）が病理学的にガイドライン治癒切除もしくは適応拡大治癒切除であった．122病変（18.2％）が非治癒切除で，24病変（3.6％）が病理学的に判定不能であった．対象症例中481症例が当センターで経過観察されていた．これら症例の長期経過では，治癒切除例のうち分割切除となった1例で局所再発を認めたが，現在までに胃癌死は認められていない．非治癒切除例のうち2例，判定不能例のうち1例に遠隔転移再発による胃癌死を認めている．よって，一括にて切除され治癒切除が病理組織学的に証明された場合においては，ガイドライン病変のみならず適応拡大病変においても高い根治性があると考えられる．

　With the development of new endoscopic resection (ER) techniques such as endoscopic submucosal dissection (ESD), removal of larger early gastric cancer (EGC) lesions has been possible. The benefit of ESD can be achieved only through careful histological examination, so an en-bloc resection is recommended. Among 671 lesions/588 patients were eligible for ER according to the current indication, and were treated by ESD from January, 1999 to August, 2002 at the National Cancer Center Hospital (NCCH). In the histological assessment, the curative resection rate was 78.2％, the non-curative resection rate was 18.2％, and the non-evaluable rate was 3.6％. 481 out of 588 patients were followed up at the NCCH. We assessed the clinical course of these patients according to the curability of ESD. Patients were divided into 4 groups (Curative resection according to the guideline, Curative resection according to the expanded indication, Non-curative resection, and Non-evaluable). No recurrence or metastasis was evident in the curative resection group, except in the long-term follow up of one patient who had local recurrence after piecemeal resection. In the non-curative resection group, after additional surgery, distant metastasis was observed in two patients during the follow-up period. In the non-evaluable group, 21 out of 22 patients were followed up after ESD without additional treatment, and local recurrence and distant LN metastasis were observed in one patient 33.6 months after ESD. High curability was able to be obtained in patients who underwent en-bloc resection in the curative resection group according to the guideline and expanded criteria.