早期大腸癌と腺腫の関係

Relationship of Adenomas to Early Colorectal Cancer

要旨　3cm以下の早期大腸癌128病変で腺腫の有無について，また1.5cm以下の早期癌68病変で癌占有率を調べた．m癌に比べてsm癌は癌占有率が高く，大きな病変が多かった．長茎型では病変が大きくなっても，癌占有率は低かった．このため，この型から進行癌へ進展する可能性は低いと推測された．腫瘤型m癌では1cm未満で癌占有率が50％と高いものが23％あった．この型では1cm以上で癌占有率30％以下の病変がm癌で90％，sm癌で8％あった．腫瘤型では腺腫からm癌・sm癌への進展が考えられた．平盤・中央陥凹型のsm癌は1cm未満にみられ，腺腫の併存を認めない病変が多かった．すなわち，1cm未満で既に腺腫との関連性を認めないことが多いと言えよう．

　This study, involving 128 cases, was undertaken to investigate firstly, whether or not early colorectal cancers 3 cm or less in the largest diameter are accompanied with adenomas (early cancers in villous tumors were excluded from the study). Secondly, to investigate the ratio of carcinomatous areas of 1.5 cm or less to the formation of early cancers. Sixty-eight cases were involved in this second investigation.

　The ratio of carcinomatous area was low in the Ip type, but high in the IIa and IIa ＋ IIc type in which there was an “sm” cancer even if less than 1 cm.

　Our results suggest that IIa and IIa ＋ IIc, even if it is small, tends to invade the deeper layer of the colonic wall.