胃癌EMRの一括切除による治癒切除の判定基準―水平切除断端と臨床経過との検討

The Decision Concerning Complete Removal with Endoscopic Mucosal Resection (EMR) for Early Gastric Cancer: The Relationship between Resection Margin and Clinical Course in Single Fragment Resection

要旨　1987年10月から1998年7月までに，国立がんセンター中央病院の適応基準に基づいて464病変に対して内視鏡的粘膜切除術(EMR)が施行された．301病変(65％)が一括切除された．一括切除された病変の水平切除断端の評価を4分類して，臨床経過との関係から検討した．一括切除された301病変中m癌は258病変(86％)で，このうち治癒切除と判定された180病変(70％)では再発は認められなかったが，追加治療されず経過観察された切除断端(＋)病変は29％，判定不能病変では15％に再発が認められた．一方，切除断端(±)病変では34病変中29病変が経過観察され，2病変(7％)に再発が認められた．すなわち，治癒切除症例では再発は認められなかったが，断端(±)症例では断端(＋)や判定不能の他の非治癒切除群と比べ再発率は低いながらも再発が認められ，外科切除で遺残癌も確認された．以上から，一括切除された病変であっても水平切除断端の正確な評価を行い，断端(－)病変のみを治癒切除とすべきである．更に，断端(±)病変では病理組織学的評価において断端(－)か断端(＋)かを明確にすることが，その後の治療方針を決定するうえで極めて重要であることが示唆された．

　Our criteria for EMR include all of the following: － (1) Well or moderately differentiated adenocarcinoma, (2) Macroscopically I, IIa and IIc type and (3) The absence of ulcerative findings. The standards of size and multiplicity are also absolute, when each lesion completely satisfies the above (1) - (3).

　Four hundred and sixty-four lesions of early gastric cancer were treated with endoscopic mucosal resection (EMR) from 1987 through 1998 in the National Cancer Center Hospital. Of these subjects, 301 lesions under-went a single fragment resection. Then we evaluated the relationship between the resection margin and the clinical course. The resection margin was classified into four groups. There was no evidence of recurrence in 180 lesions which were histopathologically judged margin free (－). The recurrence rates of other groups ［margin (±), margin (＋), unknown］ were 7％, 29％ and 15％, respectively.

　These results suggest that it is necessary to prove margin (－) before it can be decided that resection will be curative. Furthermore, to decide the therapeutic course after EMR, histopathologically, it shold be elarified whether the resection margin (±) is actually margin (－) or margin (＋).