2004结肠癌筛查和监控指南（英文）-WGO-OMGE.doc

WGO-OMGE Position Statement:Colorectal Cancer Screening and SurveillanceStatement prepared by Professor Sidney J. Winawer and approved by the WGO-OMGE Guidelines & Statements CommitteeSummer 2002, Revised 18 June 20041. introductionThere will be approximately 850,000 new cases and more than 500,000 deaths from Colorectal Cancer (CRC) world-wide this year. Risk factors for CRC include older age, family history, certain hereditary conditions, dietary factors, lack of exercise, exercise, alcohol, smoking and sedentary lifestyles. Some of these risk factors such as age cannot be changed; others such as diet require massive public education to change behavior. In the past few years, considerable evidence has accumulated that the number of people developing and dying from CRC can be dramatically reduced by screening and surveillance. This evidence has resulted in a consensus for the first time by many authoritative groups that CRC screening is effective and should be recommended.2. definitionsScreening is the testing of asymptomatic individuals to determine who is likely to have adenomatous polyps or CRC.Diagnosis is the work-up of people who have a positive screening test.Surveillance is the monitoring of people who have premalignant conditions such as Inflammatory Bowl Disease (IBD) or who receive treatment for adenomatous polyps or CRC.3. risk factors for CRCAll men and women with no other risk factors are at risk for CRC at age 50 and older. The risk is about equal for men and women. Although risk is also present below age 50, more than 90% of people with CRC are age 50 or older. The risk doubles with each decade. Factors that increase risk include a family history of 1 or 2 first degree relatives with CRC; Familial Adenomatous Polyposis (FAP) or Hereditary Non-Polyposis Colorectal Cancer (HNPCC); or personal history of IBD, adenomatous polyps or CRC.4. evidence for CRC screeningThere are now 3 randomized control trials that have reported a mortality reduction from CRC as a result of screening with a guaiac based Fecal Occult Blood Test (FOBT). The largest reduction is 33% with annual screening using a sensitive slide and lesser reductions (15-18%) using a less sensitive slide every other year. Recently, one trial reported a CRC incidence reduction as a result of detecting and removing adenomatous polyps. Immunochemical FOBTs have demonstrated excellent sensitivity and specificity. Two case control studies and a small prospective randomized trial have demonstrated a mortality reduction of 60-80% as a result of screening sigmoidoscopy. There are 2 large prospective randomized trials in progress (US & UK) examining mortality from screening flexible sigmoidoscopy. Several studies have demonstrated an increased yield of adenomatous polyps and cancer by combining FOBT and sigmoidoscopy but as yet a significant mortality reduction has not been reported.Two studies have reported the feasibility of screening colonoscopy in asymptomatic men (1 study) and in men and women (1 study). The studies have demonstrated that: approximately 10% of those screened have early stage cancer (1%) or advanced adenomas; complications are low; and approximately 30-50% of people with proximal neoplasia would not have been identified if only flexible sigmoidoscopy were done.Studies of effectiveness (incidence and mortality) have not been initiated as yet. There are no reports on screening barium enema. Newer techniques for screening are under study, including: virtual colonoscopy and fecal DNA markers, which provide additional screening options. 5. evidence for CRC surveillanceThere is strong evidence that removal of adenomatous polyps followed by colonoscopy surveillance will reduce the incidence of CRC. The follow-up surveillance intervals required can be longer than previously believed. Patients have been stratified into those at low and high risk for subsequent advanced adenomas. Double Contrast Barium Enema (DCBE) has been shown to be less accurate in detecting adenomatous polyps at follow-up. Surveillance goals after curative cancer surgery are the same as for post-polypectomy patients. IBD surveillance with colonoscopy every 1-2 years can detect early cancer and dysplasia in a high percentage of people who develop cancer with IBD.6. guidelines for CRC screening and surveillance6.1 General Guidelines: People with symptoms require a diagnostic work-up. Personal and familial factors need to be evaluated. A positive screening test requires prompt diagnostic work-up by colonoscopy and follow-up surveillance.6.2 Screening Guidelines: All men and women age 50 and older should be offered screening for adenomatous polyps and cancer with one of the follow options: Fecal occult blood testing annually with a sensitive guaiac or immunochemicaltest, flexible sigmoidoscopy every 5 years, preferably both combined, colonoscopy every 10 years, or DCBE with flexible sigmoidoscopy every 5-10 years. People with 1 or 2 first-degree relatives with colorectal cancer or an adenomatous polyp under age 60 should be offered screening beginning at age 40 with one of the above options. A family history consistent with FAP or HNPCC requires genetic counselling, possibly genetic testing and more intense surveillance at a younger age.6.3 Surveillance Guidelines: Following removal of an adenomatous polyp, a colonoscopy follow-up program should be initiated. In general most patients can have the first follow-up colonoscopy 3-5 years later depending on the number and pathology of the polyps. Some patients require earlier intervention if the colon is not cleared or if there are numerous polyps, or malignant polyps. After cancer surgery, a colonoscopy is usually done at 6 months to 1 year and then the follow-up is the same as for post-polypectomy. Long standing IBD requires colonoscopy for the detection of cancer and dysplasia every 1-2 years.More specific details can be obtained from the accompanying references.7、cost effectiveness and implementation of guidelinesAll screening approaches are as cost-effective as screening mammography and costs are saved as the cost of cancer treatment rises.With strong data, and evidence-based guidelines well established, we need now to focus our at