通过结肠镜检直肠异常隐窝病灶筛查结直肠腺瘤的临床价值研究

目的研究结肠镜检直肠异常隐窝病灶(aberrant crypt foci,ACF)对结直肠腺瘤的预警作用。方法根据患者有无直肠ACF分为ACF组(73例)和对照组(67例)。通过患者的结直肠腺瘤情况分析结肠镜检直肠ACF对于患者结直肠腺瘤的预警作用。结果 ACF组患者以非进展型腺瘤性息肉和结直肠腺癌为主。ACF组患者的满意度达94.5%,高于对照组的44.8%。患者ACF程度与结直肠腺瘤病情呈正比。结论结肠镜检直肠ACF可以有效预警结直肠癌,准确度高。     

结肠癌患者直肠异型隐窝灶中脂肪酸合成酶的表达及其意义

背景：异型隐窝灶（ACF）是结直肠上皮性肿瘤最早期的形态学改变,可经腺瘤进展至结直肠癌。脂肪酸合成酶（FAS）在多数人恶性肿瘤组织中呈高表达。目的：检测结肠癌患者直肠ACF中的FAS表达情况,探讨ACF中FAS表达异常在结直肠癌形成中的意义。方法：30例确诊的散发性结肠癌患者纳入研究。以0.2%亚甲蓝溶液行直肠黏膜染色,通过放大结肠镜寻找、识别ACF,选取隐窝数目超过30个的较大的ACF为研究对象。以免疫组化染色检测直肠ACF以及配对结肠癌组织和正常结肠组织中的FAS表达。结果：30例结肠癌患者共确定116个目标ACF,不伴异型增生91个,伴异型增生25个。结肠癌组织中的FAS阳性表达率显著高于ACF和正常结肠组织（76.7%对32.8%和10.0%,P〈0.05）,ACF与正常结肠组织间差异亦有统计学意义（P〈0.05）。伴异型增生的ACF FAS阳性表达率与不伴异型增生者无明显差异（36.0%对31.9%,P〉0.05）。结论：F.AS在结直肠癌腺瘤-癌发生序列的最早期即已出现表达异常,在结直肠癌的形成中发挥重要作用。以FAS抑制剂抑制ACF进展可能成为结直肠癌化学预防的手段之一。     

2型糖尿病患者结直肠腺瘤临床病理特征和进展期腺瘤危险因素分析

背景:结直肠腺瘤为结直肠癌的癌前病变,糖尿病可增加结直肠癌发生风险。目的:探讨2型糖尿病患者结直肠腺瘤的临床病理特征以及进展期腺瘤的危险因素。方法:回顾性连续收集2018年1月—2020年12月在浙江中医药大学附属第二医院初次行全结肠镜检查者,227例2型糖尿病结直肠腺瘤患者、553例2型糖尿病无息肉患者和与2型糖尿病腺瘤组1∶1匹配[匹配因素包括性别、年龄、体质指数(BMI)和吸烟史]的227例非糖尿病结直肠腺瘤患者纳入研究。总结2型糖尿病结直肠腺瘤患者的临床和病理特点,采用单因素和多因素分析筛选进展期腺瘤的危险因素。结果:与2型糖尿病无息肉组相比,2型糖尿病腺瘤组年龄更大,男性、吸烟者和有胆囊结石/胆囊切除史者比例更高(P均0.05)。与非糖尿病腺瘤组相比,2型糖尿病腺瘤组多发腺瘤和进展期腺瘤比例更高(16.7%对10.1%,21.6%对14.1%,P均0.05)。多因素Logistic回归分析显示,男性(OR=1.299,95%CI:1.041～1.831,P=0.008)、年龄(OR=1.129,95%CI:1.001～1.421,P=0.025)、BMI(OR=1.118,95%CI:1.022～1.715,P=0.038)和2型糖尿病(OR=1.408,95%CI:1.141～1.721,P=0.010)是进展期腺瘤的独立危险因素。结论:2型糖尿病患者有更高的结直肠多发腺瘤和进展期腺瘤检出率,男性、年龄、BMI和2型糖尿病与进展期腺瘤显著相关。     

577例大肠癌相关危险因素的研究

目的 探讨惠州地区大肠癌发病的相关危险因素.方法 对惠州地区577例大肠癌患者进行大肠癌危险因素单因素条件Logistics回归分析,纳入多因素条件Logislic回归模型进行多因素分析,计算各危险因素与大肠癌的关联程度OR值及其95％可信区间.结果 对577例大肠癌患者进行单因素条件Logistics回归分析发现,糖尿病病史、既往有大肠腺瘤性息肉病史和一级亲属患大肠腺瘤或大肠癌家族史和大肠癌的发生有关(P＜0.05).根据单因素的分析结果,将有意义的变量引入到多因素条件Logistic回归模型进行分析,结果显示糖尿病病史、既往大肠腺瘤性息肉病史、一级亲属患大肠腺瘤或大肠癌家族史是大肠癌发生的危险因素(P均＜0.05,OR值均＞1).结论 糖尿病病史、既往有大肠腺瘤性息肉病史和一级亲属患大肠腺瘤性息肉或大肠癌家族史增加了患大肠癌的危险性.     

异常隐窝病灶研究进展

近20多年来，世界上多数国家大肠癌的发病率呈上升趋势，我国大肠癌发病率上升趋势亦十分显著。一般认为绝大多数大肠癌的发生归咎于腺瘤的癌变，部分直接起源于大肠黏膜生发中心的干细胞，少数可由增生性息肉经锯齿状腺瘤癌变等。但是随着1987年Bird对变异隐窝病灶（aberrant crypt foci，ACF）的首次报道及近年来对ACF的深入研究，ACF被认为是结直肠癌发生过程中可在光镜下观察到的最小和最早期的大肠黏膜病变。     

直肠异常隐窝病灶对结肠肿瘤的预警作用

目的 评判内镜下直肠异常隐窝病灶(ACF)与结肠病变及高癌变潜能肿瘤(AN)的关系.方法 接受全结肠镜检查的正常、息肉、腺瘤及癌的患者212例,在退镜时用0.4%靛胭脂对直肠进行染色,根据直肠ACF的数目对患者分级,无ACF者为0级,ACF数目为1～4,5～9,≥10者分别为Ⅰ、Ⅱ、Ⅲ级,统计分析ACF级别与结肠病变(息肉、腺瘤和癌),高癌变潜能肿瘤(≥1 cm,绒毛状、管状绒毛状,高度异型增生或浸润癌)的关系.结果 212例患者中,72例直肠ACF为0级,48例为Ⅰ级,41例为Ⅱ级,51例为Ⅲ级.直肠有ACF(包括Ⅰ、Ⅱ、Ⅲ级)的患者发生结肠病变及结肠高癌变潜能肿瘤的概率较无ACF者明显升高,其OR值(95%CI)分别为22.352(6.716～74.395),7.982(1.838～34.672).结论 直肠ACF对结肠病变及高癌变潜能肿瘤有预示作用.     

不同阶段结直肠肿瘤分泌型卷曲相关蛋白基因甲基化及表达

目的探讨分泌型卷曲相关蛋白（sFRP）家族基因启动子CpG岛甲基化在结直肠肿瘤发生、发展和诊断中的作用。方法分别用甲基特异性PCR和逆转录PCR检测72例结直肠腺癌、33例腺瘤、18个变性隐窝灶（ACF）中sFRP基因甲基化及mRNA表达。结果正常大肠黏膜不存在sFRP基因甲基化。sFRP1、2、4、5甲基化率在腺癌中分别为93。1％、83。3％、36．1％和52．8％；在腺瘤中分别为87．9％、81．8％、24．2％和57．6％；ACF中分别为94．4％、77．8％、27．8％和55．6％。腺癌、腺瘤和ACF间sFRP基因甲基化率差异无统计学意义（P〉0．05），肿瘤组织甲基化率均高于正常黏膜及癌旁正常组织（P〈0．05）。正常黏膜表达sFRPl～5基因mRNA。与正常黏膜相比，腺癌中sFRP1、2、4、5分别在90．3％、70．8％、26．4％和61．1％的样本中表达下调（P〈0．05）；腺瘤中sFRP1、2、5分别在75．8％、45。5％和39。4％的样本中表达下调（P〈0．01）。腺癌中sFRP2、4、5表达下调较腺瘤更常见（P〈0．05）。sFRP3基因启动子不含CpG岛，仅极少数肿瘤标本（7／105）表达下调。肿瘤组织中sFRP基因表达下调与基因启动子高甲基化相关（P〈0．05）。结论sFRP基因家族在ACF中已出现高频率甲基化，是结直肠肿瘤发生常见的早期事件，可能导致sFRP基因表达下调。sFRP1、2、5甲基化可能成为早期发现结直肠肿瘤的生物学标记。     

L-FABP在大肠腺瘤和大肠癌中的表达及意义

目的探讨肝脂肪酸结合蛋白（L—FABP）在大肠腺瘤和大肠癌中的表达及意义。方法应用免疫组化法检测34例大肠癌癌组织、34例癌旁正常大肠组织及22例大肠腺瘤组织L-FABP的表达。结果大肠癌癌组织、癌旁正常大肠组织及大肠腺瘤组织中L-FABP表达率分别为50．O％、88．2％及72．7％,大肠癌中L—FABP表达率显著低于癌旁正常大肠组织和大肠腺瘤组织（P〈0．05）。大肠腺瘤组织和癌旁正常大肠组织L—FABP表达率无统计学差异（P〉0．05）。L—FABP的表达强度与大肠癌肿瘤生物学特性关系密切（P〈0．01）。结论L—FABP的下调可促进大肠癌的进展。     

放大色素结肠镜观察FAS、Ki-67在直肠异常隐窝病灶中的表达

目的:观察FAS、Ki-67在结肠腺瘤、异常隐窝病灶(aberrant crypt foci,ACF)中的表达,探讨脂肪酸合成酶(fatty acid synthase,FAS)、增殖细胞核抗原(Ki-67)的异常表达在结直肠癌癌前病变形成中的意义.方法:对34例结肠镜确诊为腺瘤性息肉患者,常规内镜检查结束时,用0.2%的亚甲蓝溶液染色直肠黏膜,然后使用放大结肠镜观察直肠寻找ACF.对结肠腺瘤性息肉、ACF及正常黏膜活检标本进行免疫组织化学分析其FAS和Ki-67的表达.结果:34例结肠腺瘤性息肉患者,其中31例直肠发现ACF,共发现并活检ACF166处(其中伴异型增生14处,不伴异型增生152处).FAS、K i-67在结肠腺瘤、A C F中呈异常高表达(P<0.01).伴异型增生ACF中FAS、Ki-67表达较不伴异型增生ACF无明显上调.结论:FAS、Ki-67在结直肠癌的癌前病变(腺瘤、ACF)呈异常高表达.结直肠癌的癌前病变存在细胞能量代谢异常及异常增殖,在ACF阶段就已经异常增殖明显,抑制FAS有望成为结直肠癌预防、治疗的靶点.     

代谢综合征组分与结直肠腺瘤性息肉复发关系的研究

背景：研究显示一些代谢综合征（MS）组分为结直肠腺瘤性息肉的危险因素,然而关注MS组分在结直肠腺瘤性息肉复发中意义的研究尚少。目的：研究MS组分与结直肠腺瘤性息肉复发的关系。方法：纳入2003年1月～2009年1月于北京大学人民医院行内镜下结直肠息肉切除术、病理诊断为腺瘤性息肉并有2年以上复查资料的成年患者,采集其包括4项MS组分（肥胖、高血压、高血糖、血脂异常）在内的12项可疑危险因素,筛选复发相关因素,以之为自变量,以研究起点之后第1～3年期间的结肠镜复查结果为因变量,行多元logistic回归分析,计算OR值并换算为RR值。结果：共138例患者纳入研究,76例（55.1%）在研究起点之后第1～3年期间复发,4例复查时发现结直肠癌年龄、高血压病史、糖尿病病史、饮酒史和多发性腺瘤以及伴发MS组分的数量与复发相关（P〈0.05）。logistic回归分析显示MS组分（OR=2.308,P〈0.01：RR=1.342）和年龄（OR=1.040,P〈0.05;RR=1.018）为复发的独立危险因素。结论：伴发MS组分的结直肠腺瘤性息肉更易复发,提示可将MS组分纳入结直肠腺瘤性息肉治疗后复查的参考指标。     

Performance value of high risk factors in colorectal cancer screening in China

AIM: To analyze the performance value of high risk factors in population-based colorectal cancer (CRC) screening in China. METHODS: We compared the performance value of the immunochemical fecal occult blood test (iFOBT) and other high risk factors questionnaire in a population sample of 13 214 community residents who completed both the iFOBT and questionnaire investigation. Patients with either a positive iFOBT and/or questionnaire were regarded as a high risk population and those eligible were asked to undergo colonoscopy. RESULTS: The iFOBT had the highest positive predictive value and negative predictive value in screening for advanced neoplasia. The iFOBT had the highest sensitivity, lowest number of extra false positive results associated with the detection of one extra abnormality for screening advanced neoplasias and adenomas. A history of chronic cholecystitis or cholecystectomy, chronic appendicitis or appendectomy, and chronic diarrhea also had a higher sensitivity than a history of adenomatous polyps in screening for advanced neoplasias and adenomas. The sensitivity of a history of chronic cholecystitis or cholecystectomy was highest among the 10 high risk factors in screening for nonadenomatous polyps. A history of chronic appendicitis or appendectomy, chronic constipation, chronic diarrhea, mucous and bloody stool, CRC in first degree relatives, malignant tumor and a positive iFOBT also had higher sensitivities than a history of adenomas polyps in screening for non-adenomatous polyps. Except for a history of malignant tumor in screening for non-adenomatous polyps, the gain in sensitivity was associated with an increase in extra false positive results associated with the detection of one extra abnormality. CONCLUSION: The iFOBT may be the best marker for screening for advanced neoplasias and adenomas. Some unique high risk factors may play an important role in CRC screening in China.     

Relationship of human rectal aberrant crypt foci and formation of colorectal polyp:One-year following up after polypectomy

AIM:To clarify the relationship of human rectal aberrant crypt foci and formation of colorectal polyp.METHODS:Eighty-nine subjects were recruited from the population of Japanese individuals who underwent polypectomy at Yokohama City University Hospital.All patients had baseline adenomas removed at year 0 colonoscopy.Aberrant crypt foci(ACF) were defined as lesions in which the crypts were more darkly stained with methylene blue than normal crypts and had larger diameters,often with oval or slit-like lumens and a thicker epithelial lining.RESULTS:A total of 366 ACFs were identified in 89 patients;all had baseline adenomas removed at the first examination(year 0) colonoscopy and returned for the second(year 1).ACF in the lower rectum were assessed at year 0 and study group were divided into two groups depend on ACF numbers,0-3 or over 3.All participants were examined in the number and maximum size of adenoma.There was no statistical difference in number and maximum size of ACF at year 0,however,maximum size of adenoma was larger in over 3 group than 0-3 group at year 1.CONCLUSION:The number of ACF may be a predictive factor of relatively large adenoma incidence in the pilot phase study.     

Use of colonoscopy as a primary screening test for colorectal cancer in average risk people

OBJECTIVE: The use of colonoscopy as a primary screening test for colorectal cancer (CRC) in average risk adults is a subject of controversy. Our primary objective was to build a predictive model based on a few simple variables that could be used as a guide for identifying average risk adults more suitable for examination with colonoscopy as a primary screening test. METHODS: The prevalence of advanced adenomas was assessed by primary screening colonoscopy in 2210 consecutive adults at least 40 yr old, without known risk factors for CRC. Age, gender, and clinical and biochemical data were compared among people without adenomas, those with non-advanced adenomas, and those with any advanced neoplasm. A combined score to assess the risk of advanced adenomas was built with the variables selected by multiple logistic regression analysis. RESULTS: Neoplastic lesions were found in 617 subjects (27.9%), including 259 with at least one neoplasm that was 10 mm or larger, villous, or with moderate-to-severe dysplasia, and 11 with invasive cancers. Advanced lesions were more frequent among men, older people, and those with a higher body mass index (BMI). These three variables were independent predictors of advanced adenomas in multivariate analysis. A score combining age, sex, and BMI was developed as a guide for identifying individuals more suitable for screening colonoscopy. CONCLUSIONS: Age, gender, and BMI can be used to build a simple score to select those average risk adults who might be candidates for primary screening colonoscopy.     

Polyp surveillance after surgery for colorectal cancer

Purpose

Although it is known that those patients who have developed colorectal cancer (CRC) are at a higher risk to develop metachronous adenoma or CRC, no study has been performed to analyze the relationship between the risk factors and the time course for the formation of postoperative adenoma using survival analysis.

Methods

One hundred seventy-six patients with CRC, who had received surgical resection, were endoscopically followed-up to detect the development of metachronous adenoma or adenocarcinoama. The association between the risk factors such as age, synchronous adenomas with index CRC or other clinicopathological variables and the formation of postoperative adenoma was assessed using the logrank test and the Cox proportional hazard model.

Results

Age over 60, synchronous lesions at the time of surgery for primary CRCs and presence of diabetes mellitus (DM) as the associated disease were positively related to the formation of postoperative adenoma. Among those patients with the three risk factors, only 27.8% remained adenoma-free during 5?years after operation, whereas in the group without any risk factor, it was 90.4%.

Conclusions

From our data, age over 60, synchronous adenomas or CRCs and DM were the potential risk factors for the postoperative formation of adenoma or CRC, and they should be taken into consideration when defining the appropriate interval of postoperative colonoscopy.     

Screening of first degree relatives of patients operated for colorectal cancer: evaluation of fecal calprotectin vs. hemoccult II.

Fecal calprotectin (CPT) is elevated in the majority of patients with known colorectal cancer (CRC), but the specificity is not clarified. AIM: To evaluate if a CPT test (PhiCal ELISA) was more sensitive than Hemoccult II test in detecting colorectal neoplasia, and to obtain reference values in subjects with normal colonoscopy. To evaluate a possible relation between number and extent of dysplasia of adenomas in first degree relatives of patients with CRC and the stage of the carcinoma in the index casus. Further to study the prevalence of CRC and adenomas in the first degree relatives of patients operated for CRC. METHOD: In a multicenter study, 253 first degree relatives of patients with CRC, aged 50-75 years (mean age 60 years) underwent colonoscopy after having delivered stool samples and three Hemoccult II slides. RESULTS: In 237 first degree relatives from 148 patients with CRC, polyps were found in 118 (50%). Seventy three (31%) had adenomas and 17 had adenomas > or =10 mm. Five had asymptomatic cancers. The specificity of fecal CPT for adenomas at cut off levels 15 mg/l. The sensitivity of Hemoccult II for adenomas was 8%, and 4/5 of patients with carcinoma had negative Hemoccult II. The specificity for adenomas was 95%. CONCLUSION: Fecal CPT test was more sensitive than Hemoccult II in detecting colorectal neoplasia but the specificity was lower. In a high risk group like first degree relatives of patients with CRC, there are good reasons to consider fecal CPT as a first test in selecting patients for endoscopy.     

Immunological fecal occult blood test vs. serum ferritin for detection of colorectal neoplasia in high risk asymptomatic population

Introduction: Fecal occult blood tests (FOBT) (biochemical or immunological) are based on the fact that most of the polyps or cancers bleed. Anemia due to iron deficiency is a wellknown sign for colorectal cancer (CRC). Ferritin is frequently used to select candidates for colonoscopy. Objective: To determine and compare the diagnostic value of immunological fecal occult blood test vs. ferritin for the detection of colorectal neoplasia (cancer or polyps) in high-risk patients. Methods: A transversal prospective study at National Cancer Institute, Mexico City, in consecutive asymptomatic subjects at high risk for CRC was performed, comparing two tests (immunological against serum ferritin) with colonoscopy plus histopathology. Both tests were performed in a blindly fashion previous to colonoscopy. Results: Fifty patients were included in the study; twenty-eight patients had colorectal neoplasia (21 CRC, 7 adenomas). All immunologic tests for fecaloccult blood were positive in patients with colorectal lesions (sensitivity, 98%). There was no difference between the mean ferritin levels in patients with CRC or adenomas vs. those with negative colonoscopy (p = 0.58). The cutoff point where significant relationship between serum ferritin levels and colon lesions was established was ?46 ng/mL. In anemic patients with serum ferritin levels <46 ng/mL, the test had a sensitivity 53%, specificity 86%, positive predictive value 83%, and negative predictive value of 59% (p = 0.003). Conclusions: The immunological FOBT is a better diagnostic tool than serum ferritin for screening of colonic neoplasms.     

Potential for prevention: a cohort study of colonoscopies and removal of adenomas in a FIT-based colorectal cancer screening programme

Introduction: Evidence suggests that colorectal cancer (CRC) screening using guaiac faecal occult blood tests (gFOBT) reduces the CRC burden by facilitating timely removal of adenomas. Yet, the faecal immunochemical test (FIT) is being implemented in many countries. The aim of this study was to analyse the risk of having adenomas detected when invited for FIT-based screening as compared to those not yet invited.

Material and Methods: The study was designed as a register-based retrospective cohort study. The potential for prevention was estimated as number of individuals who had no adenomas, non-advanced adenomas, and advanced adenomas detected per 1000 invited/not yet invited individuals and the relative risk (RR) of each of the three outcomes.

Results: A total of 1,359,340 individuals were included, 29.6% of whom had been invited and 70.4% had not yet been invited to participate in CRC screening. Compared with the not yet invited population, the invited group had a RR of no adenomas of 2.28 (2.22–2.34) and a RR of advanced adenomas of 7.41 (6.93–7.91). The RR of colonoscopy was 2.93 (2.87–2.99) for the invited population compared with the not yet invited population.

Conclusion: The RR of having a colonoscopy was three times higher among those invited compared to those not yet invited for CRC screening and twice as often those who had been invited compared to those not yet invited had no adenomas detected. Still, the risk of advanced adenomas was more than seven times higher among the invited population, indicating that the screening programme holds great potential for reducing the CRC burden.

Abbreviations: CI: Confidence interval; CRC: Colorectal cancer; FIT: Faecal immunochemical test; ICD: International Classification of Disease; RR: Relative risk     

Colon cancer screening: which non-invasive filter tests?

The following non-invasive stool tests for colorectal cancer (CRC) screening exist: guaiac or immunochemical fecal occult blood testing (FOBT), genetic stool tests and the M2-PK. Currently the most widely used tests are guaiac-based (gFOBT). Several randomized controlled trials have shown that gFOBT are able to achieve a reduction in CRC-related mortality. This reduction is achieved by detecting asymptomatic cancers at an early stage with a better prognosis. However, gFOBT have a low sensitivity for colorectal adenomas and are thus unlikely to be able to reduce the incidence of CRC. Furthermore, gFOBT are not specific for human blood and can be influenced by external factors. Immunochemical tests (iFOBT) only detect human blood in the stool. In two recent randomized studies from the Netherlands comparing guaiac and immunochemical tests in the asymptomatic population, iFOBT were found to detect more cancers than gFOBT. Furthermore, iFOBT were able to detect more advanced adenomas thus having the potential to be able to reduce the incidence of CRC as well as CRC-related mortality. In the recently released European CRC screening guidelines, iFOBT are considered the screening test of choice. Several questions remain however. It is currently unknown what the optimal cut-off value for an iFOBT to be considered positive should be and what the number of stool samples is that are required. Genetic stool tests detect mutations in stool that can be found in CRC. The original test testing for 21 genetic changes was found to be superior to gFOBT for the detection of cancers. However, the sensitivity was moderate (51.6%) and the sensitivity for advanced adenomas was low. In the meantime the test has been modified improving DNA extraction and reducing the number of mutations tested for as well as including a methylation marker. The efficacy of the modified test in the screening population is unknown. M2-PK is an isomer of the enzyme pyruvate kinase that is involved in glycolysis. Studies have found a good sensitivity for cancers, a low sensitivity for advanced adenomas with a specificity of around 80%. Further studies in the screening population are required.     

自然人群序贯粪隐血试验连续性结直肠癌普查的队列研究：19年结果分析

筛查是早期发现结直肠癌（CRC）的重要手段。目的：评价自然人群序贯粪隐血试验（SFOBT）连续性CRC普查在提高早期CRC检出率、患者长期生存率和降低CRC发生率方面的作用。方法：于1987～2005年，应用SFOBT对一组基本固定的中老年人群（初次普查人群3002例）行连续性CRC普查。每1～2年接受一次普查者计入普查组，连续3年或3年以上未接受普查者计入未普查组。FOBT阳性者行结肠镜检查。于北京军区总医院行手术治疗的1033例CRC患者作为对照组。结果：19年中普查人群共发生CRC52例，总CRC发生率为90．4／10万人·年。普查组共检出CRC25例，漏诊7例，CRC检出率为57．6／10万人·年，发生率为73．8／10万人·年；未普查组发生CRC20例，发生率为141．4／10万人·年。普查组DukesA／B期患者比例（95．5％对31．2％和43．9％，P〈0．05）和5年生存率（77．8％对33．3％和39．8％，P〈0．05）显著高于未普查组和对照组。SFOBT筛查CRC的19年总敏感性为90．6％，特异性为98．0％，阳性预测值为3．2％，阴性预测值为99．99％。结论：SFOBT应用于自然人群连续性普查可提高早期CRC检出率和患者5年生存率。切除普查中发现的腺瘤可明显降低CRC发生率。该筛查方案具有较高的敏感性和特异性，但仍需高度关注其结肠镜检查的依从性.