早期大腸癌内視鏡治療後における異時性多発病変の実態

Realities of the Detection of Multiple Metachronous Lesions after Colonoscopic Treatment for Early Colon Cancer

要旨●今回筆者らの施設で内視鏡治療を行い，1年以上経過観察を行った早期大腸癌87例の異時性多発病変の発見の状況を調査した．内視鏡治療後5年後の異時性多発病変の累積発見率は56.7％だった．異時性多発病変の臨床病理学的特徴は，病変数は1個のものが多く，右側大腸に多い傾向がみられ，大きさは概ね10mm未満だった．異時性多発病変の経過は治療例，経過観察例共に良好だった．異時性多発病変の発見にかかわる危険因子に関する多変量解析の結果，同時性ポリープ3個以上が独立した危険因子であった．早期大腸癌内視鏡治療後の適切なサーベイランス法は，今回の調査結果とこれまでの報告をもとにしても現時点では不明であり，今後報告の蓄積が必要であると考えられる．

　In this study, we investigated the state of the detection of multiple metachronous lesions in 87 patients with early-stage colorectal cancer who had undergone colonoscopic treatment at our institution and were followed-up for at least one year. The cumulative detection rate of metachronous multiple lesions five years after colonoscopic treatment was 56.7%. Examination of clinicopathological characteristics of multiple metachronous lesions indicated that they tended to develop as a single lesion and occur in the right large intestine, and most were smaller than 10mm. The clinical course of multiple metachronous lesions was favorable both in patients who were treated and those who only underwent follow-up observations. The results of multivariate analysis of risk factors of multiple metachronous lesions revealed that an independent risk factor was the presence of three or more synchronous polyps. There is no established appropriate surveillance method for early-stage colorectal cancer after colonoscopic treatment; therefore, more research regarding this topic is needed in the future.