早期大腸癌的篩檢、診斷與治療

Screening, Diagnosis and Treatment of Early Colorectal Cancer

邱瀚模(Han-Mo Chiu)

《中華民國癌症醫學會雜誌》 24卷3期 (2008/06) Pp. 148-156

https://doi.org/10.6588/JCOS.2008.24.3.2

摘要

根據衛生署的統計，目前大腸直腸癌已高居國人男性與女性十大癌症死因的第三位，並有與年遽增之趨勢。由於大腸直腸癌有較長之癌前病期，提供了篩檢與治療的好機會，實際上大腸直腸癌若能早期發現並早期治療，其預後是相當良好的。
過去西方的大規模研究已經證實以糞便潛血反應篩檢大腸直腸癌可以顯著降低大腸直腸癌死亡率，國民健康局也自2004年起開始全國性的大腸直腸癌篩檢計劃。此外，美國National Polyp Study也已經證實切除大腸直腸腺瘤可以大幅降低來日罹患大腸直腸癌的風險與因大腸直腸癌死亡之風險。除現有之篩檢工具（如糞便潛血反應、乙狀結腸鏡、大腸鏡、下消化道攝影等）以外，近年來也陸續有許多新開發之篩檢工具，如糞便DNA檢查及電腦斷層虛擬大腸鏡等等。此外，在以社區為基礎或以醫院為基礎的篩檢研究也發現代謝症候群或糖尿病也是罹患大腸直腸癌的重要危險因子，因此除對於高危險群需重新認定以外，篩檢策略之擬定也必須一併重新考量。大腸內視鏡是所有檢查的最終把關者，檢查時幾個重點是必須要注意的：(1)高偵測率(2)辨別腫瘤性與非腫瘤性病灶(3)辨別良性腫瘤與惡性腫瘤(4)辨別惡性腫瘤浸潤深度以決定治療方法。以目前新發展的染色內視鏡、擴大內視鏡與窄帶影像技術均可以大幅提高診斷的精確度。
腺瘤與早期大腸癌是內視鏡治療的良好對象，除了恢復快以外，可以達到根治的目的才是內視鏡治療普及的根本原因。目前浸潤深度侷限於黏膜層者是內視鏡治療的絕對適應症，而粘膜下層浸潤小於1000微米者也絕大多數無淋巴結轉移，是內視鏡治療的相對適應症。
由於診斷技術與儀器之進步，早期大腸癌的診斷與治療已經進入全新的紀元。往昔認為腫瘤或癌症就必須開腹手術的觀念已經逐漸改觀，然第一線腸胃科醫師與內視鏡醫師也必須明瞭及修習新的診斷技術與治療技能，方能將最適合的治療方式應用於病人身上。

關鍵字

癌症篩檢 ； 早期大腸直腸癌 ； 大腸內視鏡 ； 診斷

並列摘要

Colorectal caner (CRC) is nowadays the third leading cause of cancer mortality in both genders in Taiwan. Accumulating evidence has indicated that the early detection and removal of colorectal adenomas greatly reduces the mortality and incidence of CRC, and reliable detection and resection of colorectal neoplasia before they become malignant is the underlying rationale for CRC screening.
According to the previous studies from Western countries, stool testing can effectively reduce CRC mortality and data from National Polyp Study of U.S. has also proven that polypectomy can reduce both incidence and mortality of CRC. In addition to conventional screening tools, some newly developed techniques, such as stool DNA and CT colonography, can help screening of CRC and their application in screening setting can be anticipated. Furthermore, there are several emerging risk factors of CRC, such as metabolic syndrome, that raise the attention of clinicians and epidemiologists recently. These findings can help formulating future screening strategies and programs.
During colonoscopic examination, several issues should be fulfilled: (1) high detection rate for neoplastic lesions, (2) discrimination between neoplastic and non-neoplastic lesions, (3) discrimination between benign and malignant neoplastic lesions, and (4) accurate prediction of invasion depth of malignant lesions. By way of modern techniques such as chromoendoscopy, magnifying endoscopy and narrow band imaging, improvement of diagnostic accuracy of colonoscopy can be achieved. Mucosal cancer and invasive cancer with submucosal invasion less than 1000μm and without vascular or lymphatic invasion is the indication of endoscopic resection for colorectal neoplastic lesions. Clinicians should be aware of these new knowledge, new technologies and enable themselves to provide minimal invasive procedures for their patients.

並列關鍵字

cancer screening ； early colorectal cancer ； colonoscopy ； diagnosis