遺伝性非ポリポーシス大腸癌の長期経過

Long-term Observation of Individuals with HNPCC

要旨　遺伝性非ポリポーシス大腸癌（hereditary non-polyposis colorectal cancer ; HNPCC）は，ミスマッチ修復遺伝子の異常により，大腸や子宮内膜，胃，小腸，腎盂・尿管などの発癌リスクが高くなる体質である．この体質をもつ者の80％は生涯に1回以上，大腸癌を罹患する．したがって，大腸癌の早期発見および前癌病変である腺腫の摘除を目的とする大腸内視鏡検査による厳重な経過観察が必要である．HNPCCにおける経過観察のための大腸内視鏡検査の間隔は，筆者らの症例やいくつかの報告において大腸癌や腺腫の増大が早いものがあるため，1年ごとが望ましい．

　HNPCC（hereditary non-polyposis colorectal cancer）is a genetic predisposition to colorectal cancer as well as other cancers affecting the endometrium, stomach, small intestine, renal pelvis, ureter, etc. due to an abnormality in DNA mismatch repair genes. Individuals with this condition have an 80％ lifetime risk of developing colorectal cancer at least once. Therefore, they should be carefully observed by periodic colonoscopy for early detection of colorectal cancers and/or removal of adenomas as precancerous lesions. For this purpose, an annual colonoscopic examination is desirable since some cases with rapidly progressed colorectal cancers or adenomas in HNPCC have been identified in our practice as well as in some reports from other clinics.