深達度からみた大腸sm癌の内視鏡治療適応拡大の可能性と危険性―内視鏡治療施行大腸sm癌症例の検討から

Possibility of Broadening of the Indication for Endoscopic Treatment for Submucosally Invasive Colorectal Carcinoma and the Risks Involved : Analysis of Cases with Submucosally Invasive Carcinoma Treated Endoscopically

要旨　内視鏡的治療施行大腸sm癌80病変を対象に，深達度からみた内視鏡的切除の限界を明らかにするため，深部断端陽性率などの臨床病理学的所見と遺残，局所・転移再発，予後との関係を検討した．sm浸潤度は，400μm未満29例，400～1,500μm21例，1,500μm以上30例で，深部断端陽性率は13/80（16.3％）であった．13例中，隆起型病変が10例と高頻度であったが，sm浸潤度1,500μm未満の病変（6.0％；3/50）は1,500μm以上の病変（33.3％；10/30）に比べて有意に低率であった．局所遺残は，辺縁m癌の遺残1例と内視鏡的切除を途中で中断したsm遺残の1例のみで，ともに深部断端陽性例であった．ほかには追加手術例，経過観察例ともに遺残・転移再発は認めず，sm浸潤度1,500μm未満の病変は内視鏡的に局所根治可能であると考えられた．

　We analyzed 80 cases of submucosally invasive colorectal carcinoma resected endoscopically in order to clarify the possibility of broadening of the indication for endoscopic mucosal resection (EMR) and the risks it might involve. Regarding the invasion depth of lesions, 29 lesions were within 400μm, 21 lesions were between 400 and 1,500μm, 30 lesions were more than 1,500μm, respectively. The deep cut-end positive rate was 16.3% (13/80). The deep cut-end positive cases were composed of 10 polypoid type lesions and three other macroscopic type lesions. Cases within 1,500μm in invasion depth (6.0% ; 3/50) showed a significantly lower incidence of positive cut-end than those more than 1,500μm in invasion depth (33.3% ; 10/30). Local residual tumor after EMR was confirmed in two cases by additional surgical resection. One was a case with intramucosal residual carcinoma. Another was a case with submucosal residual carcinoma, which case was interrupted during the EMR. Additional surgical resection or follow-up without further resection showed that, except in these two cases, there was neither recurrence in local residue nor metastasis. These results indicated that it is possible to perform the complete EMR for submucosally massive invasive colorectal carcinomas whose invasion depth is 1,500μm.