大腸SM（T1）癌に対する外科手術の中・長期成績

The Medium and Long-term Surgical Outcome of T1 Colorectal Cancer

要旨●大腸T1癌に対する外科手術の中・長期成績を明らかにするため，当科で外科手術が行われた193例を検討した．疾患特異的5年生存率は，T1癌全体で97.2％であり，Stage別ではStage Iで97.6％，Stage IIIaで100％，Stage IVで50％であった．一方，5年無再発生存率は，T1癌全体で95.0％であり，Stage Iで96.2％，Stage IIIaで91.7％，Stage IVで50％であった．有意な再発リスク因子は局在Rbであった．有意な原癌死リスク因子は，局在Rbと簇出Grade 2/3であった（多変量解析では局在Rbのみ）．T1癌に対する外科手術の成績は大変良好であるが，Rb癌の術後は慎重なフォローアップを要することが示唆された．

　We reviewed 193 cases of T1 colorectal cancer to evaluate medium and long-term surgical outcomes at our department. The five-year disease-specific survival rate among all T1 cancers was 97.2% with 97.6% in Stage I, 100% in Stage IIIa, and 50% in Stage IV. However, the five-year recurrence-free survival rate among all T1 cancers was 95.0% with 96.2% in Stage I, 91.7% in Stage IIIa, and 50% in Stage IV. Statistically significant risk factor of recurrence was location of rectum below the peritoneal reflection（Rb）. Moreover, statistically significant risk factors for cancer death were Rb location and budding Grade 2/3 using univariate analysis, and only Rb location using multivariate analysis.

　Surgical outcomes for T1 colorectal cancer were good, but careful observation is required during post-operative follow-up of Rb cancer.