| 特集名 | 消化器癌予防 up‒to‒date | |
|---|---|---|
| 題名 | 胆道癌 (1) 胆石症と胆道癌 | |
| 発刊年月 | 2015年 10月 | |
| 著者 | 駒込 昌彦 | 埼玉医科大学総合医療センター肝胆膵外科・小児外科 |
| 著者 | 別宮 好文 | 埼玉医科大学総合医療センター肝胆膵外科・小児外科 |
| 著者 | 小澤 文明 | 埼玉医科大学総合医療センター肝胆膵外科・小児外科 |
| 著者 | 牧 章 | 埼玉医科大学総合医療センター肝胆膵外科・小児外科 |
| 【 要旨 】 | 胆石が胆道系の癌（胆道癌；胆囊癌，肝外胆管癌と肝内胆管癌）の発癌原因となるかどうかは長く議論されている．本邦での多目的コホート研究と海外のmeta‒analysisでは，胆石保有者における胆囊癌の発生率が高いとされた．しかし，無症状胆囊結石を経過観察した場合に，無症候性胆囊結石から胆囊癌の発生はまれとの報告もある．現時点では，直径3cm以上の大結石，充満結石，陶器様胆囊などは胆囊癌合併の高リスクとされるが，無症候性胆囊結石に対する予防的な胆囊摘出術を施行することは胆石症ガイドラインでも推奨されていない． 一方，肝内結石は肝内胆管癌の高リスク群とされており積極的な治療が行われている．とくに50％以上の肝萎縮を伴う症例では肝内胆管癌合併のリスクが高く肝切除が望ましいとされる．内視鏡的治療の進歩に伴い肝・胆切除を施行せずに肝内結石を除去することが可能となったが，胆管狭窄部が残存することとなり，将来的な肝内胆管癌の発生を見据えた慎重な経過観察が必要であるとされる． 今後は胆道系の癌の罹患率や死亡数も増加すると予想され，胆石，胆道炎を含めた発癌機序のさらなる解明とともに，癌発症高リスク群の抽出と予防的治療の確立が期待される． |
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| Theme | Up‒to‒date of the Protection of Gastroenterological Cancers | |
|---|---|---|
| Title | Cholelithias and Biliary Tract Cancer | |
| Author | Masahiko Komagome | Department of Hepato‒Biliary‒Pancreatic & Pediatric Surgery, Saitama Medical University and Saitama Medical Center |
| Author | Yoshifumi Beck | Department of Hepato‒Biliary‒Pancreatic & Pediatric Surgery, Saitama Medical University and Saitama Medical Center |
| Author | Fumiaki Ozawa | Department of Hepato‒Biliary‒Pancreatic & Pediatric Surgery, Saitama Medical University and Saitama Medical Center |
| Author | Akira Maki | Department of Hepato‒Biliary‒Pancreatic & Pediatric Surgery, Saitama Medical University and Saitama Medical Center |
| [ Summary ] | The relationship between cholelithiasis and biliary malignancies, such as gallbladder cancer and bile duct cancer, is still controversial. A study of a Japanese cohort showed that cholecystolithiasis is a risk factor for biliary malignancy, and this finding was supported by a foreign meta‒analysis of risk factors for gall bladder cancer. However, some reports have shown that the incidence rate of biliary malignancy during the observational period among asymptomatic cholecystolithiasis patients was not different from the general population. A large stone, more than 3 cm in diameter, multiple gallbladder stones, and porcelain gallbladder are widely established risk factors for gallbladder cancer；however, preemptive cholecystectomy is not recommended for asymptomatic cholecystolithiasis as per the Japanese therapeutic guideline for gallbladder stones. The presence of intra‒hepatic biliary stones is a risk factor for intra‒hepatic bile duct cancer. Intra‒hepatic biliary stones with severe hepatic atrophy and greater than 50 % reduction of regional liver volume are significantly associated with increased risk for intra‒hepatic bile duct cancer, and hepatic resection is recommended. Recent progress in the use of endoscopic interventions has enabled endoscopic lithotomy of intra‒hepatic biliary stones. However the procedure leaves a stricture in the biliary tree that increases the risk for another biliary stone or malignancy development ; therefore, intensive surveillance is recommended after the procedure. The incidence and mortality rate of biliary malignancy has increased recently. Therefore, there is a need to develop surveillance and preemptive therapy for high‒risk patients, as well as to address the mechanism of biliary carcinogenesis. |
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