6) 表面型早期大腸癌の深達度診断

Endoscopic Diagnosis of Depth of Invasion in Superficial Flat and Depressed Type Early Colorectal Cancer using Magnification Colonoscopy

要旨　表面型早期大腸癌における拡大内視鏡診断の意義を明らかにするために，①拡大内視鏡診断能の隆起型病変との比較検討，②SM深部浸潤を反映する通常内視鏡所見（8因子）との比較検討を行った．早期大腸癌における拡大内視鏡を用いた深達度診断は，隆起型よりも表面型において優れた正診が得られた．また，多変量解析にて，拡大内視鏡診断VI（invasive pattern）：Odds比209.79）と通常内視鏡所見の緊満感（Odds比8.61）がSM深部浸潤と相関する独立因子として抽出された．以上から，表面型早期大腸癌に対する拡大内視鏡による深達度診断は有用であり，これを普及することが，適格な治療に結びつくものと考える．

　We conducted a retrospective study on the effectiveness of endoscopic diagnosis using magnification colonoscopy to clarify the accuracy of the magnification criterion VI (invasive pattern) for superficial flat and depressed type early colorectal cancer. We compaired it with 1) the protruded type and 2) the eight conventional endoscopic criteria for positive association with submucosal (sm) deep invasion.

　The accuracy rate for superficial flat and depressed type early colorectal cancer using the magnification criterion was higher than that for the protruded type. Based on multivariate analysis, the two independent risk criteria for sm deep invasion were the magnification criterion and the conventional endoscopic finding of tumor expansion (odds ratio ; 209.79,8.61, respectively). The results of our investigation indicated that diagnosis of invasive depth in superficial flat and depressed type early colorectal cancer was more accurate when magnification colonoscopy was used. So facilitate its widespreads use in future, we suggest simplification in diagnosing depth of invasion by using the magnification criterion which is easier to use and more objective in nature.