ESD/EMRからみた未分化型混在早期胃癌の取り扱い―早期胃癌外科切除例からの検討

Treatment for Early Gastric Cancer of Differentiated and Undifferentiated Mixed Type

要旨　外科切除された早期胃癌508例より，分化型腺癌（分腺）と未分化型腺癌（未腺）の組織混在についてその病理組織学的特徴，リンパ節転移との関係を検討した．M癌において分腺優位混在型では純分腺型に比べて，有意にtub2混在が多く，腫瘍長径が大きく，脈管侵襲陽性率が高かった．またリンパ節転移陽性率も高い傾向が認められた．今回の対象群では，分腺優位混在型のM癌，ly0，v0症例においてULの有無および大きさにかかわらずリンパ節転移は認められなかったが，症例数が少ないため，さらなる症例集積が必要と考えられた．分腺優位混在型は純分腺型と比較して，転移能が高い可能性が示唆されたことから，今後もそれらの取り扱いについては慎重に行うべきと考えられた．

　Early gastric carcinoma of differentiated and undifferentiated mixed type was considered, using 508 early gastric carcinomas surgically resected from 2002 to 2006 in Shizuoka Cancer Center. We examined relationships between clinicopathological features and the rate of lymph node metastasis. There were statistically significant differences between purely differentiated type and mixed type (in which differentiated type were predominant) in tub 2, gender, size of the lesion and lymphovascular involvement. It was found that the rate of lymph node metastasis in mixed type (in which the differentiated type was predominant) was higher than that in the purely differentiated type. In this study, there was no lymph node metastasis regardless of ulceration and size of tumor in mixed typed cancers (in which differentiated type was predominant) with depth M and no lymphovascular involvement. ESD treatment for differentiated and undifferentiated mixed type of adenocarcinoma needs to be investigated further, because there are fewer cases on, which to base our conclusions.