伺机性筛查新模式在结直肠肿瘤患者一级亲属中的探索性研究

目的探究结直肠病房筛查新模式在结直肠肿瘤患者一级亲属筛查的有效性。 方法采用结直肠肿瘤风险问卷评分、粪便潜血免疫化学检测（FIT）以及粪便多靶点FIT-DNA检测对2019年10月至2021年7月在中国医学科学院肿瘤医院结直肠外科就诊的结直肠癌及进展期腺瘤患者的一级亲属进行检测，根据检测结果将一级亲属进行筛查风险分层以及肠镜检查推荐分类，分析不同分层分类后一级亲属的肠镜依从率与病变检出率。 结果共250名受试者被纳入本研究。总体人群肠镜依从率为38.0%（95/250），肠镜病变检出率为9.5%（9/95）；高风险人群（A类推荐人群）肠镜依从率为78.9%（15/19），肠镜病变检出率为26.7%（4/15）；中风险人群（B类推荐人群）肠镜依从率为61.2%（30/49），肠镜病变检出率为16.7%（5/30）；低风险人群（C类推荐人群）肠镜依从率为27.5%（50/182），肠镜病变检出率为0（0/50）。 结论三种筛查方法联合使用可以高效精准地区分一级亲属的筛查风险，此方案是一个可以在病房开展的有效可行的结直肠肿瘤患者一级亲属人群的伺机性筛查新模式。     

MNP-RT-PCR技术在大肠癌和腺瘤性息肉筛查和鉴别中的应用

目的：探讨纳米磁珠-实时荧光聚合酶链反应（ MNP-RT-PCR）技术在大肠癌和腺瘤性息肉筛查与鉴别中的应用。方法选择500例高危患者（大肠癌组26例、腺瘤性息肉组148例、其他组326例）,取少量粪便分别用MNP-RT-PCR技术和粪便潜血两种方法进行检测,比较两种方法的灵敏度和特异度。同时收集上述患者中的443例患者（大肠癌组26例、腺瘤性息肉组148例、正常黏膜组269例）,在肠镜下刷检病变部位或正常部位,再用MNP-RT-PCR方法检测COX-2表达量,比较三组COX-2表达的差异。结果 MNP-RT-PCR法筛查大肠癌的灵敏度为76．9％,特异度为74．5％,筛查腺瘤性息肉的灵敏度为71．8％,特异度76．3％;粪便潜血筛查大肠癌的灵敏度为65．4％,特异度为63．7％,筛查腺瘤性息肉的灵敏度为42．6％,特异度为64．2％。大肠癌组肠镜刷检样本中COX-2表达量显著高于腺瘤性息肉组和正常黏膜组（P均＜0．05）,腺瘤性息肉组显著高于正常黏膜组（P＜0．05）。结论对大肠癌和腺瘤性息肉患者筛查,MNP-RT-PCR技术优于粪便潜血;应用MNP-RT-PCR技术检测肠镜刷检样本中COX-2表达量,对鉴别大肠癌、腺瘤性息肉和大肠正常黏膜有很大帮助。     

单克隆抗体人群大肠癌普查意义再探讨

目的进一步探讨单克隆抗体人群大肠癌普查的意义．方法应用以新型抗人胃肠癌单抗CMU15系列多株制备的大便金标免疫试剂（简称金标法）对11272例年龄19岁～89岁的广东邮电职工进行大便初筛，1010例阳性组和随机抽样217例阴性组均作纤维乙状结肠镜或全结肠镜的检查确诊和对照，同时其中的647例又做了粪隐血试验，做对比研究．另外一组人群共2762例通过问卷调查，内容包括：息肉病史、便血及大便性状改变、下腹部疼痛、一级亲属大肠肿瘤史及年龄50岁以上，五项中有一项，直接纤维肠镜检查，共285例，其结果与金标法进行比较．结果11272例全标法阳性1215例，接受肠镜检查1010例，检出率：大肠癌0．58％（6／1010），脉瘤15．0％（152／1010），其他类型息肉14．1％（143／1010），溃疡性结肠炎0．5％（5／1010）；金标阴性组：大肠癌0，腺瘤5．4％（12／217），其他类型息肉5．4％（12／217），溃疡性结肠炎0．两组结果有显著差异（P＜0．05）．隐血组仅能检出50％的肠癌、11．1％腺瘤、9．8％其他息肉．问卷组：大肠癌0、腺瘤8．1％、其他息肉9．1％、溃疡性结肠炎0．结论以新型抗人胃肠癌单抗CMU15系列多株制备的大便金标免疫法试剂做为人群大肠癌普查的初筛手段，对大肠癌及癌前病变有较高的敏感性．     

老年人大肠息肉与大肠癌

为了解老年人大肠息肉和大肠癌的临床特点，更好地预防老年人大肠肿瘤的发生和早期诊断大肠癌，对２４８例老年人大肠息肉和大肠癌的临床及病理作一回顾性分析。结果老年人大肠息肉和大肠癌的检出率分别为３３．３％和２３．３％，并有以下特点：（１）大肠息肉和大肠癌是老年人便血的主要原因，炎性息肉、腺瘤性息肉及大肠癌三者的便血率依次增高；（２）息肉检出率显著高于普通人群息肉检出率，且腺瘤性息肉占７３．８％；（３）多发性息肉比例较高，并以腺瘤性息肉为主，占８０．７％，且多发生于不同的肠段；（４）老年人大肠癌低恶性程度者多；（５）大肠腺瘤性息肉常与大肠癌并存，二者多发生于不同肠段。因此，我们认为便血是老年人大肠镜检查的有力指征；大肠镜检查时不应满足于远端大肠病变的诊断，应尽可能检查全大肠；对老年人大肠息肉，尤其是多发性息肉及直径大于１．０ｃｍ者应积极切除。     

代谢综合征因素与大肠肿瘤的关系

目的研究代谢综合征因素如血糖、甘油三酯、胆固醇及高血压与大肠肿瘤发病的关系。方法回顾分析2002年1月至2006年6月住院并接受结肠镜检查308名患者的临床资料。结果308例患者中197例患者（64．0％）检出大肠息肉，包括炎性息肉38例（12．3％），瘤性息肉159例（51．6％），其中进展期息病变为78例（25．3％）。分别以患者空腹血糖、甘油三酯、胆固醇、收缩压水平分组，经年龄校正后对上四分之一区组与下四分之一区组息肉检出情况进行比较，结果甘油三酯及血压上四分之一区息肉检出率（75．3％，80．0％），瘤性息肉检出率（63．6％，66．2％），进展期息病变检出率（36．4％，30．8％），均显著高于下四分之一区检出率（除血压分区进展期息病变检出率比较P〈0．10，余均P〈0．05。高甘油三酯对大肠息肉及瘤性息肉OR分别为2．55，2．21，高血压对大肠息肉及瘤性息肉OR分别为2．30，2．16）。血糖及胆固醇分区息肉检出率及瘤性息肉检出率相比差异无统计学意义（P〉0．05）。结论高甘油三酯及高血压可能为大肠肿瘤发病的危险因素，该类患者进展期息病变检出率较高，需进行大肠肿瘤的筛查。     

169例青中年大肠恶性肿瘤患者内镜和病理特征分析

目的探讨青中年大肠恶性肿瘤患者的内镜和病理特征,以提高其诊断水平。方法分析169例青中年、113例老年大肠恶性肿瘤患者的临床表现、发病部位、肠镜特征、组织学类型、Dukes分期,并进行比较。结果青中年患者中以便血为首发症状者占52．6％,病变位于直肠者占68．0％。肠镜表现以溃疡型为主（50．9％）,而老年组以肿块型为主（P〈0．01）。分化不良的大肠癌患者在青中年组为56．8％,而老年组为38．9％（P〈0．01）。青中年组大肠癌DukesC＋D期占78．4％,与老年组比较,差异有显著性（P〈0．01）。282例患者中发现大肠癌267例,类癌4例,淋巴瘤11例。大肠癌、类癌、淋巴瘤的肠镜下表现、病理特征各不相同。结论大肠恶性肿瘤以直肠为最好发部位,但右半结肠肿瘤并不少见。青中年人大肠恶性肿瘤的特征与老年人不同,肠镜下表现以溃疡型多见,具有病理分化程度低、Dukes分期晚的特点。     

内镜筛查及切除息肉病理检查在早期大肠癌诊断中的意义

为探讨临床内镜筛查及切除息肉病理检查在早期大肠癌诊断中的价值，总结分析了北医大三院１９７８年至１９９６年９月所有大肠镜检查的资料。１８年间行大肠镜检查１８１２３例、内镜下息肉切除２３４５例，共发现早期大肠癌８０例、８６个癌灶，占同期发现大肠癌总数的１５．１％（８６／５６９）。早期大肠癌的诊断率呈上升趋势，特别是１９８７年开展临床内镜筛查以来升高尤为显著。相关分析显示早期大肠癌的诊断率与内镜检查特别是内镜下息肉切除后的病理检查密切相关，提示该两项方法为诊断早期大肠癌的有效方法。     

免疫法和化学法粪便隐血试验对下消化道易出血疾病筛查价值的对照研究

目的 探讨免疫法粪便隐血试验(IFOBT)和化学法粪便隐血试验(FOBT)对下消化道易出血疾病的筛查价值.方法 对经大肠镜明确诊断的260例下消化道易出血疾病及50例正常对照者分别进行IFOBT及FOBT检查,并结合临床资料分析其相应结果.结果 IFOBT检测大肠癌、大肠息肉、炎症性肠病的阳性率均高于FOBT(前者为100%,41%,100%,后者为87%,11%,52%)(P《0.05),假阳性率则低于FOBT(2%与18%)(P《0.05).IFOBT和FOBT均与大肠癌解剖部位无关(P》0.05);与Dukes分期呈正相关(r=0.30,P《0.05),即阳性病例主要分布在Dukes B和C期;阳性率均高于癌胚抗原阳性率(P《0.05).IFOBT和FOBT其结果与息肉的最大长径呈正相关(r=0.66.P《0.05),且随着腺瘤性息肉中具有癌前病变性质的绒毛成分的增多而增加(P《0.05).结论 IFOBT对于筛查结直肠癌和腺瘤性息肉等肠道易出血疾病具有良好的临床应用价值,并显著优于FOBT.     

门诊患者大肠镜检查的临床意义

目的探讨对有症状就诊人群进行大肠镜检查的临床意义。方法１９９５年～１９９６年对１２４６例因有下消化道症状就诊于消化科的患者进行大肠镜检查。结果肠粘膜炎性改变４３７例，溃疡性结肠炎５５例，息肉１８７例（腺瘤１２１例，增生性息肉６６例），肠癌１１１例，未发现病变４１１例。在１８７例中发现并摘除息肉２９１枚，其中１３例１３枚息肉有局部恶变者电凝摘除后随访１年无异常发现。１１１例肠癌中ＤｕｃｋＡ６０例。腺癌、息肉的检出率与年龄呈正相关（Ｐ＜０．０５），但≤２９岁组腺癌、息肉也分别检出１．８％和１６．４％。结论有症状就诊人群大肠镜检查是一可行、安全、费用不高和省时的方法，能明显减少大肠癌的发病率和死亡率。     

多原发大肠癌的内镜诊断及其与腺瘤的关系

目的提高临床医师对多原发大肠癌的重视程度,研究腺瘤与肠癌的关系。方法总结８４３例大肠癌中多原发癌２２例（同时癌１７例,异时癌５例）的临床资料。结果多原发癌检出率２．６１％;２２例共有癌灶４９个,乙状结肠以下占６２．６％;２２例中共检出腺瘤３１个,癌变息肉达６１．２％,亦多分布在乙状结肠和直肠。结论多原发大肠癌并不少见,多原发大肠癌与腺瘤之间关系密切。对大肠癌患者行肠镜检查时,对所见息肉均应常规活检,并治疗,以减少多原发大肠癌的发生。     

上海松江区结直肠癌普查研究的初步结果

目的探讨粪便隐血试验结合大肠镜检查作为大肠癌普查方式的可行性。方法2006年9月至2007年5月,对上海市松江区无症状且结直肠癌普通危险度的≥50岁人群以及40～49岁志愿参加普查者行免疫组化法粪便隐血试验,连续3次排便中任意2次粪便标本送检,对任何1次粪便隐血阳性（包括弱阳性）的患者行全结肠镜检查。对息肉的数量、分布位置及病理结果进行统计。结果≥50岁受检者共2692例,粪便隐血试验阳性者184例,阳性率6．8％,共56例患者发现了64枚结肠息肉,包括腺瘤性息肉34枚、炎性息肉15枚、增生性息肉15枚,发现直肠癌1例。40～49岁志愿普查者共582例,隐血试验呈阳性者28例,阳性率4．8％,共6例患者发现了6枚息肉,包括腺瘤性息肉1枚、炎性息肉5枚,并发现肠癌2例。多数息肉分布于左半结肠。结论对无症状的结直肠癌普通危险度人群的普查能较早发现结肠息肉,对粪便隐血试验阳性的患者行全结肠镜检查可能较适合社区及广大农村地区结直肠癌的大规模普查。     

Sensitivity, Specificity, and Predictive Value of Fecal Occult Blood Testing (Hemoccult II) for Colorectal Neoplasia in Symptomatic Patients: A Prospective Study with Total Colonoscopy

Objective: To evaluate the specificity, sensitivity, and positive predictive value of fecal occult blood testing (FOBT) in symptomatic patients, with colonoscopy as the gold standard, and to assess the usefulness of FOBT as an ancillary examination in symptomatic patients for whom total colonoscopy is indicated.
Methods: We studied 439 consecutive patients who underwent Hemoccult II testing before total colonoscopy.
Results: The sensitivity, specificity, and positive predictive value for colorectal neoplasia (cancer and adenomatous polyps) was 76.5%, 56.7%, and 27.6%, respectively. The sensitivity, specificity, and positive predictive value for colorectal cancer were 69.2%, 73.2%, and 7.3%, respectively.
Conclusions: The sensitivity, specificity, and positive predictive value of FOBT are difficult to estimate from screening programs, because Hemoccult-negative individuals do not undergo examination of the colon, and many of the Hemoccult-positive cases do not undergo total colonoscopy. With total colonoscopy serving as the gold standard, FOBT does not appear to be of much value as an ancillary examination in patients with symptoms potentially attributable to the lower gastrointestinal tract.     

Evaluation of a fecal occult blood test with reverse passive hemagglutination for colorectal neoplasm screening

AIM: To evaluate the one and three sampling reverse passive hemagglutination fecal occult blood test (RPHA FOBT) for colorectal neoplasm screening.METHODS: A group of 3034 individuals with histories of colorectal polyps and/or ulcers were screened for colorectal cancer. Three day fecal samples were collected and 60 cm fiberoptic colonoscopy was conducted for each subject. The fecal samples were tested for occult blood with the RPHA method and the endoscopic and histopathological diagnoses were used as standard reference for evaluation. The sensitivity, specificity and positive and negative predictive values of different samplings were compared.RESULTS: About 521 cases of colorectal neoplasms were detected, including 12 cases of colorectal cancer and 509 cases of polyps. Results showed that the mean sensitivity of one sampling RPHA FOBT for colorectal neoplasm was only 13.2%, the specificity was 90.3% and the positive and negative predictive values were 21.3% and 83.4%, respectively; while for the three sampling, taking one positivity as positive, the sensitivity increased to 22.0%, the specificity decreased to 81.6% and the positive and negative predictive values were 19.7% and 83.6%, respectively.CONCLUSION: A single RPHA FOBT seems to be less sensitive for screening for colorectal neoplasms. Since it is convenient and economical, RPHA FOBT remains the most practical procedure for detection of early colorectal cancer and polyps if it is combined with other screening methods.     

A comparison of the immunochemical fecal occult blood test and total colonoscopy in the asymptomatic population

BACKGROUND & AIMS: The fecal occult blood test (FOBT) is recommended as a screening test for colorectal cancer, but there are few reliable studies on the accuracy of immunochemical FOBT. The aim of this study was to analyze the sensitivity of immunochemical FOBT and to compare the results with the findings from complete colonoscopy. METHODS: Asymptomatic adults underwent 1-time immunochemical FOBT and total colonoscopy simultaneously. The prevalence and location of colorectal neoplasia were determined by colonoscopy. The results of immunochemical FOBT and the colonoscopic findings were compared. RESULTS: Of 21,805 patients, immunochemical FOBT was positive in 1231 cases (5.6%). The sensitivity of 1-time immunochemical FOBT for detecting advanced neoplasia and invasive cancer was 27.1% and 65.8%, respectively. In addition, the sensitivity for invasive cancer according to Dukes' stage showed 50.0% for Dukes' stage A, 70.0% for Dukes' stage B, and 78.3% for Dukes' stages C or D. The sensitivity for detecting advanced neoplasia at the proximal colon was significantly lower than that detected in the distal colon (16.3% vs 30.7%, P = .00007). CONCLUSIONS: Although the screening of asymptomatic patients with immunochemical FOBT can identify patients with colorectal neoplasia to a certain extent, the sensitivity is relatively low and different according to the tumor location. Therefore, programmatic and repeated screening by immunochemical FOBT may be necessary to increase sensitivity for colorectal cancer detection.     

Interval faecal occult blood testing in a colonoscopy based screening programme detects additional pathology

BACKGROUND: Colonoscopic based surveillance is recommended for patients at increased risk of colorectal cancer. The appropriate interval between surveillance colonoscopies remains in debate, as is the "miss rate" for colorectal cancer within such screening programmes. AIMS: The main aim of this study was to determine whether a one-off interval faecal occult blood test (FOBT) facilitates the detection of significant neoplasia within a colonoscopic based surveillance programme. Secondary aims were to determine if invitees were interested in participating in interval screening, and to determine whether interval lesions were missed or whether they developed rapidly since the previous colonoscopy PATIENTS: Patients enrolled in a colonoscopic based screening programme due to a personal history of colorectal neoplasia or a significant family history. METHODS: Patients within the screening programme were invited to perform an immunochemical FOBT (Inform). A positive result was followed by colonoscopy; significant neoplasia was defined as colorectal cancer, adenomas either > or =10 mm or with a villous component, high grade dysplasia, or multiplicity (>/=3 adenomas). Participation rates were determined for age, sex, and socioeconomic subgroups. Colonoscopy recall databases were examined to determine the interval between previous colonoscopy and FOBT offer, and correlations between lesion characteristics and interval time were determined. RESULTS: A total of 785 of 1641 patients invited (47.8%) completed an Inform kit. A positive result was recorded for 57 (7.3%). Fifty two of the 57 test positive patients completed colonoscopy; 14 (1.8% of those completing the FOBT) had a significant neoplastic lesion. These consisted of six colorectal cancers and eight significant adenomas. CONCLUSIONS: A one off immunochemical faecal occult blood test within a colonoscopy based surveillance programme had a participation rate of nearly 50% and appeared to detect additional pathology, especially in patients with a past history of colonic neoplasia.     

A population-based, community estimate of total colon examination: the impact on compliance with screening for colorectal cancer

OBJECTIVE: Colorectal cancer screening is underutilized. Total colon examination (TCE), such as with colonoscopy, can have a significant effect on the measured compliance with screening, as colonoscopy may be able to be performed as infrequently as once every 10 yr. In a population-based survey we determined the prevalence and validated the self-reporting of TCE and assessed its impact on compliance with screening. METHODS: We interviewed an age- and sex-stratified random sample of 50- to 79-yr-old residents in two communities in southwestern Pennsylvania. Subjects reported ever having had and duration since last use of fecal occult blood testing (FOBT), flexible sigmoidoscopy (FS), rigid proctoscopy, barium enema, and colonoscopy. Self-reports of colorectal testing were validated via retrieval of procedure reports. RESULTS: Out of 1223 individuals sampled, 496 completed a telephone interview (40.6% overall and 58.3% of eligible contacts). In those without personal or family histories of colorectal cancer or personal histories of polyps (n = 377), 50%, 19.6%, 39.8%, and 17.5% reported ever having had FOBT, FS, barium enema, and colonoscopy, respectively. Thirty-one percent reported having FOBT within the previous year or FS within the previous 5 yr. Including TCE within the previous 5 yr increased the measured compliance to 39.7%. Compliance was significantly greater among subjects with family histories of colorectal cancer (62.9% vs 39.7%, odds ratio = 2.6, 95% CI = 1.3-5.2). Self-reports of recent colonoscopy were verified in 29 of 35 instances (83%). CONCLUSION: The prevalence of TCE in this population was significant, and including TCE substantially increased measured compliance with colorectal cancer screening. Self-reported use of colonoscopy was validated as accurate.     

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.     

Colonoscopy in asymptomatic individuals with a family history of colorectal cancer

A prevalence screening program with colonoscopy was undertaken in four kindreds manifesting the cancer family syndrome. Forty-five percent of counseled patients underwent colonoscopy, providing 42 asymptomatic individuals. Seven patients (17%) were found to have adenomatous or villous polyps; two of these were malignant and one showed epithelial atypia. Three of the seven patients with polyps had multiple lesions. Only two patients had rectosigmoid polyps. From these limited data, colonoscopy is recommended as a useful screening procedure in individuals at high risk for colorectal cancer.     

First-degree relatives of patients with advanced colorectal adenomas have an increased prevalence of colorectal cancer.

BACKGROUND & AIMS: The risk of colorectal cancer in relatives of patients with adenomatous colonic polyps is not well defined. This study assessed whether finding colonic neoplasia during screening colonoscopy was related to the family history of colorectal cancer among the participants' parents and siblings. METHODS: Self-reported family history of colorectal cancer was recorded for all participants in a screening colonoscopy study. The size and location of all polyps were recorded before their removal and histologic examination. Participants were grouped according to the most advanced lesion detected. RESULTS: Three thousand one hundred twenty-one patients underwent complete colonoscopic examination. Subjects with adenomas were more likely to have a family history of colorectal cancer than were subjects without polyps (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.09-1.70). The finding of a small (<1 cm) tubular adenoma as the most advanced lesion was associated with only a modest increase in the OR of colorectal cancer in family members (OR, 1.26; 95% CI, 0.99-1.61), but the presence of an advanced adenoma was associated with a higher OR (OR, 1.62;5% CI, 1.16-2.26). Younger age of adenoma diagnosis was not related to a higher prevalence of a family history of colorectal cancer. CONCLUSIONS: Relatives patients with advanced colorectal adenomas have an increased risk of colorectal cancer. Individuals with advanced colorectal adenomas should be counseled about the increased risk of colorectal cancer among their relatives.     

The role of colonoscopy in screening persons with family history of colorectal cancer

Abstract First-degree relatives of colorectal cancer patients are at increased risk for developing colorectal neoplasms. In order to assess the potentiality of colonoscopy screening in this high-risk population, 213 asymptomatic family members (age range 30-69 years, mean 42.8 years) of those patients with colorectal cancer received colonoscopic examination at Chang-Gung Memorial Hospital from April 1992 to May 1994. Twenty-eight persons with 42 lesions (polyps or cancer) were identified, including 28 adenomas, nine hyperplastic polyps and five adenocarcinomas. The positive detection rate was 9.9% for adenoma and 2.3% for cancer. Colorectal neoplasms afflicted males more frequently than females (16.7 vs 5.7%, P < 0.05) and occurred less frequently in those < 40 years of age (5.5 vs 17.2%, P < 0.05). Forty-two per cent of the detected neoplastic lesions were beyond the reach of 60 cm flexible sigmoidoscopy and 36% of adenomas were < 0.5 cm in size and would be missed if patients were screened by air contrast barium enema. Cost analysis revealed that the charges of both screening colonoscopy and screening flexible sigmoidoscopy/air contrast barium enema were approximate. Colonoscopy also has a high acceptability and safety. It appears appropriate to use colonoscopy, rather than flexible sigmoidoscopy or air contrast barium enema, as an initial screening procedure for persons with a family history of colorectal cancer, especially those > 40 years of age.