Motives for non-adherence to colonoscopy advice after a positive colorectal cancer screening test result: a qualitative study

Setting Participants with a positive faecal immunochemical test (FIT) in screening programs for colorectal cancer (CRC) have a high risk for colorectal cancer and advanced adenomas. They are therefore recommended follow-up by colonoscopy. However, more than ten percent of positively screened persons do not adhere to this advice.Objective To investigate FIT-positive individuals’ motives for non-adherence to colonoscopy advice in the Dutch CRC screening program.Subjects Non-adherent FIT-positive participants of the Dutch CRC screening program.Design We conducted semi structured in-depth interviews with 17 persons who did not undergo colonoscopy within 6 months after a positive FIT. Interviews were undertaken face-to-face and data were analysed thematically with open coding and constant comparison.Results All participants had multifactorial motives for non-adherence. A preference for more personalised care was described with the following themes: aversion against the design of the screening program, expectations of personalised care, emotions associated with experiences of impersonal care and a desire for counselling where options other than colonoscopy could be discussed. Furthermore, intrinsic motives were: having a perception of low risk for CRC (described by all participants), aversion and fear of colonoscopy, distrust, reluctant attitude to the treatment of cancer and cancer fatalism. Extrinsic motives were: having other health issues or priorities, practical barriers, advice from a general practitioner (GP) and financial reasons.Conclusion Personalised screening counselling might have helped to improve the interviewees’ experiences with the screening program as well as their knowledge on CRC and CRC screening. Future studies should explore whether personalised screening counselling also has potential to increase adherence rates.

Key points

• Participants with a positive FIT in two-step colorectal cancer (CRC) screening programs are at high risk for colorectal cancer and advanced adenomas. Non-adherence after an unfavourable screening result happens in all CRC programs worldwide with the consequence that many of the participants do not undergo colonoscopy for the definitive assessment of the presence of colorectal cancer. Little qualitative research has been done to study the reasons why individuals participate in the first step of the screening but not in the second step. We found a preference for more personalised care, which was not reported in previous literature on this subject. Furthermore, intrinsic factors, such as a low risk perception and distrust, and extrinsic factors, such as the presence of other health issues and GP advice, may also play a role in non-adherence. A person-centred approach in the form of a screening counselling session may be beneficial for this group of CRC screening participants.

     

免疫法粪便隐血试验对早期大肠癌流行病学研究的临床意义

目的探讨以免疫法粪便隐血试验(iFOBT)为主要筛查方法,提高早期大肠癌诊断率的临床意义。方法应用问卷调查、实验室检测(iFOBT、CEA、CA72-4、M-CSF)、肠镜及病理检查,对10000名自然人群进行大肠癌的序贯筛查。结果收回有效问卷6997份,依据调查问卷分值分为低度危险组(≤5分)、可疑组(>5～<8分)、高度危险组(≥8分)3组,3组共3697例进行iFOBT检测,各组iFOBT阳性率分别为13.34%、18.23%、99.17%,3组阳性率比较,差异具有统计学意义(P<0.05或P<0.01)。检出早期结肠癌6例,其中高度危险组5例,可疑组1例。结肠癌患者iFOBT(定量)以及CEA、CA72-4、M-CSF等血清学指标均高于结肠息肉、溃疡性结肠炎、慢性结肠炎患者(P均<0.05)。结论以iFOBT为主的序贯筛查法是发现早期大肠癌的主要方法,与某些血清指标相结合,可提高大肠癌的检出率,肠镜及病理检查可最后确诊。     

Why do some participants in colorectal cancer screening choose not to undergo colonoscopy following a positive test result? A qualitative study

Objective: Our aim was to investigate why participants opted out of colonoscopy following a positive screening result for colorectal cancer.

Design: Semi-structured, qualitative, single interviews. We audio-recorded and transcribed all interviews verbatim and used Strauss and Corbin’s concept of open, axial, and selective coding to identify the main categories shared across all interviews. These formed the basis of our findings.

Setting: A Danish national colorectal cancer screening programme.

Subjects: Single interviews with 13 participants who declined to have a colonoscopy.

Main outcome measures: Reasons to decline colonoscopy after positive screening test.

Results: Participants gave 42 different reasons for deciding not to have a colonoscopy and we coded them into nine main categories; Practical barriers, Discomfort of the examination, Personal integrity, Multimorbidity, Feeling healthy, Not having the energy, Belief that cancer is not present, Risk of complications, and Distrust in the accuracy of the iFOBT.

Conclusions: Our findings suggest that some practical barriers could be quite easily addressed, by offering the participants alternative management and procdures.

Implications: Further research is needed to examine how widely our findings are represented in the general population, and how general practitioners should consult with patients who have opted out of colonoscopy, despite a positive screening result.

• Key points

• Some screening participants are reluctant to proceed with further diagnostic tests for colorectal cancer following a positive screening result.

• ??Interviews with people, who had refused a follow-up colonoscopy, discovered nine categories (42 reasons) of reasons for refusal.

• ??Reluctance can be addressed by offering support with pre-procedure preparations and alternatives to colonoscopy.

• ??General practitioners face ethical dilemmas and challenges, when patients at risk of colorectal cancer decline to proceed with screening.

     

A novel multitarget stool DNA test for colorectal cancer screening

Review of: Imperiale TF, Ransohoff DF, Itzkowitz SH, Levin TR, Lavin P, Lidgard GP, Ahlquist DA, Berger BM. Multitarget stool DNA testing for colorectal-cancer screening. N Engl J Med 2014;370(14):1287–97.

This Practice Pearl reviews the results of a prospective, multicenter, cross-sectional clinical study that evaluated the performance of a new multitarget stool DNA (or mt-sDNA) screening test for colorectal cancer (CRC) and compared it with a fecal immunochemical test (FIT) in individuals at average risk for CRC. The potential impact of this test on the future of CRC screening is also discussed in a brief commentary. mt-sDNA testing is a noninvasive screening test designed to detect DNA biomarkers associated with colorectal neoplasia and occult hemoglobin in the stool. The sensitivity of mt-sDNA testing for detection of CRC was 92.3%, compared with 73.8% for FIT (p = 0.002). Sensitivity for detecting advanced precancerous lesions was 42.4% for mt-sDNA testing and 23.8% for FIT (p < 0.001). The specificities of mt-sDNA testing and FIT were 86.6% and 94.9%, respectively (p < 0.001). mt-sDNA testing thus may be a first-line screening option for asymptomatic individuals at average risk for CRC who do not want to have a colonoscopy.     

PillCam colon capsule endoscopy compared with colonoscopy for colorectal tumor diagnosis: a prospective pilot study

BACKGROUND AND AIMS: Colonoscopy is regarded as the gold standard for colorectal cancer (CRC) screening. PillCam capsule endoscopy could be an alternative approach for screening large populations. We report a pilot evaluation in humans of the safety, feasibility, and performance of colon capsule endoscopy compared with colonoscopy. PATIENTS AND METHODS: Patients included in this single-center comparative study had presented for screening colonoscopy or there was suspicion of polyps or CRC. The capsule was ingested in the morning. After excretion, colonoscopy was performed. Significant findings were defined either as polyps > 6 mm, or three or more polyps of any size. Colonoscopy and colon capsule endoscopy (CCE) review were performed by independent physicians. RESULTS: 41 patients (26 women), mean age 56 years (range 26 - 75) were included, and all had complete colonoscopies. Four patients were excluded due to technical problems and one could not swallow the capsule; thus, 36 patients were considered in the analysis. In six the capsule had not been expelled at 10 hours and was retrieved endoscopically. CCE identified 19 of the 25 patients (76 %) with positive findings and 10 of the 13 (77 %) with significant lesions detected by colonoscopy. CCE detected seven lesions not seen at colonoscopy and two tumors were detected by both examinations. Overall sensitivity of CCE to detect significant lesions was 77 %, specificity was 70 %, positive predictive value was 59 %, and negative predictive value was 84 %. No adverse events occurred. CONCLUSION: CCE showed promising accuracy compared with colonoscopy. This new noninvasive technique deserves further evaluation as a potential CRC screening tool.     

Cost-Effectiveness of Multitarget Stool DNA Testing vs Colonoscopy or Fecal Immunochemical Testing for Colorectal Cancer Screening in Alaska Native People

ObjectiveTo estimate the cost-effectiveness of multitarget stool DNA testing (MT-sDNA) compared with colonoscopy and fecal immunochemical testing (FIT) for Alaska Native adults.Patients and MethodsA Markov model was used to evaluate the 3 screening test effects over 40 years. Outcomes included colorectal cancer (CRC) incidence and mortality, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). The study incorporated updated evidence on screening test performance and adherence and was conducted from December 15, 2016, through November 6, 2019.ResultsWith perfect adherence, CRC incidence was reduced by 52% (95% CI, 46% to 56%) using colonoscopy, 61% (95% CI, 57% to 64%) using annual FIT, and 66% (95% CI, 63% to 68%) using MT-sDNA. Compared with no screening, perfect adherence screening extends life by 0.15, 0.17, and 0.19 QALYs per person with colonoscopy, FIT, and MT-sDNA, respectively. Colonoscopy is the most expensive strategy: approximately $110 million more than MT-sDNA and $127 million more than FIT. With imperfect adherence (best case), MT-sDNA resulted in 0.12 QALYs per person vs 0.05 and 0.06 QALYs per person by FIT and colonoscopy, respectively. Probabilistic sensitivity analyses supported the base-case analysis. Under varied adherence scenarios, MT-sDNA either dominates or is cost-effective (ICERs, $1740-$75,868 per QALY saved) compared with FIT and colonoscopy.ConclusionEach strategy reduced costs and increased QALYs compared with no screening. Screening by MT-sDNA results in the largest QALY savings. In Markov model analysis, screening by MT-sDNA in the Alaska Native population was cost-effective compared with screening by colonoscopy and FIT for a wide range of adherence scenarios.     

128层螺旋CT结肠成像在结直肠癌诊断中的应用

目的 探讨128层螺旋CT结肠成像(CTC)在结直肠癌诊断中的临床应用价值.方法 选择82例疑似结直肠癌患者进行CTC和结肠镜检查,以结肠镜病理结果为标准,分析CTC诊断结直肠癌的灵敏度、特异度、阳性预测值、阴性预测值、定位、分型;其中16例手术的结直肠癌患者,以手术病理分期为标准,分析CTC在结直肠癌T分期中的准确度...     

结直肠癌机会性筛查的临床应用探讨

目的 探讨结直肠癌机会性筛查（OS）的临床应用,旨在为进一步完善大肠癌筛查流程和提高筛查效率提供依据。方法 回顾性分析2019年1月-2020年12月该院3 398例结直肠癌OS阳性,并完成全结肠镜检查的患者的临床资料。完成高危因素问卷调查（HRFQ）和粪便免疫化学检测（FIT）后,建议对两种筛查方法中,任意一种结果呈阳性的患者,进行结肠镜检查。统计受检者的年龄、性别、病变检出情况和病变部位,根据初筛结果,比较不同筛查方法结直肠肿瘤检出率的情况。结果 3 398例受检者中,HRFQ(-) FIT （+）组进展期腺瘤和结直肠癌检出率高于HRFQ(+) FIT （-）组,差异均有统计学意义（P <0.05）。在非进展期腺瘤检出率方面,HRFQ(-) FIT （+）组明显低于HRFQ(+) FIT （+）组,差异有统计学意义（P <0.05）。FIT对结直肠肿瘤的敏感度总体上优于HRFQ,且FIT对远端结直肠肿瘤的敏感度高于近端,差异均有统计学意义（P <0.05）。结论 HRFQ与FIT组合,比FIT或HRFQ单独使用,能筛选出更多的高危人群,从而检测出更多的结直肠肿瘤,...     

A prospective study of a new immunochemical fecal occult blood test in Korean patients referred for colonoscopy

OBJECTIVES: The exquisite performance characteristics of an immunochemical fecal occult blood test (IFOBT) are well understood. We evaluated the diagnostic validity of a new IFOBT for colorectal neoplasia in patients undergoing colonoscopy and compared its results with two other commercially available IFOBTs. DESIGN AND METHODS: Eighty-five consecutive patients referred for colonoscopy were studied. We performed three different IFOBTs, namely, HM-Jack, Instant-View, and a newly developed OcculTech on each fecal specimen. RESULTS: OcculTech was easy to perform and had a sensitivity, specificity, and positive predictive value of 58.3%, 76.3%, and 27.9%, respectively, for the detection of colorectal cancers and >or=1 cm adenomas. OcculTech showed higher sensitivity than the automatic analyzer, HM-Jack. No improvement was obtained by combining tests. CONCLUSIONS: The OcculTech test had performance characteristics comparable to the two other IFOBTs. This study confirms the usefulness of the OcculTech test for colorectal neoplasia screening.     

Knowledge and feelings about colorectal cancer among the Jewish adult population in Israel: A mixed methods study

BackgroundFew previous studies found that people's knowledge of colorectal cancer (CRC) risk factors and symptoms is a predictor of high compliance with CRC screening. Feelings about CRC have rarely been examined.AimThis mixed method study is aimed at examining knowledge and feelings about CRC among the Jewish adult population in Israel.MethodsOne hundred and ninety six Jewish Israelis were interviewed using semi-structured face to face personal interviews. Clinical characteristics and knowledge about CRC were analyzed by quantitative methods. Feelings about CRC were analyzed by the qualitative constant comparative method.ResultsMost of the participants were at risk for developing CRC due to their native background as Jews of Eastern European origin. The most well known risk factor was family history of CRC, but only a third were aware of it. Screening for CRC by colonoscopy was known to about half the participants. CRC evoked negative feelings of fear of contracting an oncological disease, stress as a result of a new realty, sadness at the possibility of late discovery, disgust and embarrassment because of the involvement of an intimate area and the connection to body secretions. Positive feelings of optimistic faith and hope were found with regard to survival.ConclusionThe knowledge level of the participants about CRC symptoms, risk factors, and recommended screening was low to moderate. CRC evoked mainly negative feelings. Increasing knowledge about CRC and reducing negative feelings evoked by CRC are essential.     

粪便SDC2基因甲基化检测联合结肠镜在早期结直肠癌筛查中的意义

目的探讨粪便SDC2基因甲基化检测联合结肠镜在早期结直肠癌(CRC)筛查中的意义。方法选择2018年1月-2019年10月在深圳市宝安区中心医院体检的1 000例体检者作为研究对象,使用试剂盒分别检测粪便SDC2基因甲基化和血浆SEPT9基因甲基化,对两者任一结果为阳性者再行结肠镜检查。比较SDC2和SEPT9基因甲基化检测的阳性率以及两者联合结肠镜对进展性腺瘤和CRC的检出率。结果在1 000例筛查对象中,粪便SDC2基因甲基化检测阳性率明显高于血浆SEPT9基因甲基化〔18.10%(181/1 000)比9.80%(98/1 000)〕,差异有统计学意义(P<0.05);粪便SDC2基因甲基化检测联合结肠镜对进展性腺瘤和CRC的检出率均明显高于血浆SEPT9基因甲基化检测联合结肠镜筛查〔进展性腺瘤检出率:2.50%(25/1 000)比1.00%(10/1 000),CRC检出率:1.50%(15/1 000)比0.50%(5/1 000)〕,差异均有统计学意义(均P<0.05)。结论粪便SDC2基因甲基化检测是一种简单无创的CRC筛查新技术,患者接受程度更高,能够避免大规模肠镜筛查带来的弊端,联合结肠镜检测可作为CRC早期筛查的首选策略。     

Delayed sample arrival at the laboratory does not lead to more false negatives in the Danish population screening for colorectal cancer

In Denmark, biennial population screening for colorectal cancer was introduced in 2014 for all aged 50–74 years. Five laboratories representative for the regional division of Denmark perform the immunochemical testing of faecal occult blood in the screening samples (iFOBT, OC-Sensor (Eiken Chemical, cut-off 100 µg/L)). In July 2016, a new agreement on the public post-delivery entailed an increased lag time (five days) from the screening participant drops the screening sample into a mail-box until sample arrival at the laboratories. Previous work had reported that a lag time above five days led to more false negative iFOBT tests. We investigated if this was true also under Danish conditions. We performed two stability tests; one with sample storage at 30?°C for 14 days (N?=?60), and another with sample storage at room temperature for 13 days (N?=?10). We extracted data from our laboratory information system (LABKA) on all iFOBT tests performed in the entire Central Denmark Region (N?=?104,328 patients) during the last six months for each calendar year 2014–16. For each year, we computed the distribution of iFOBT tests below and above cut-off. Our stability tests showed no positive samples switching to false negative after storage; however, some negative samples turned false positive, especially at 30?°C. The data showed no change in the distribution of iFOBT tests below and above cut-off after July 2016. We found no evidence that an enhanced lag time increased the number of false negative iFOBT tests in the Danish screening program for colorectal cancer.     

Health Care Provider Characteristics Associated With Colorectal Cancer Screening Preferences and Use

ObjectiveTo assess health care provider (HCP) preferences related to colorectal cancer (CRC) screening overall, and by HCP and patient characteristics.Participants and MethodsWe developed a survey based on the Theoretical Domains Framework to assess factors associated with CRC screening preferences in clinical practice. The survey was administered online November 6 through December 6, 2019, to a validated panel of HCPs drawn from US national databases and professional organizations. The final analysis sample included 779 primary care clinicians (PCCs) and 159 gastroenterologists (GIs).ResultsHCPs chose colonoscopy as their preferred screening method for average-risk patients (96.9% (154/159) for GIs, 75.7% (590/779) for PCCs). Among PCCs, 12.2% (95/779) preferred multi-target stool DNA (mt-sDNA), followed by fecal immunochemical test (FIT), (7.3%; 57/779) and guaiac-based fecal occult blood test (gFOBT) (4.8%; 37/779). Preference among PCCs and GIs generally shifted toward noninvasive screening options for patients who were unable to undergo invasive procedures; concerned about taking time from work; unconvinced about need for screening; and refusing other screening recommendations. Among PCCs, preference for mt-sDNA over FIT and gFOBT was less frequent in larger compared with smaller clinical practices. Additionally, preference for mt-sDNA over FIT was more likely among PCCs with more years of clinical experience, higher patient volumes (> 25/day), and practice locations in suburban and rural settings (compared to urban).ConclusionBoth PCCs and GIs preferred colonoscopy for CRC screening of average-risk patients, although PCCs did so less frequently and with approximately a quarter preferring stool-based tests (particularly mt-sDNA). PCCs’ preference varied by provider and patient characteristics. Our findings underscore the importance of informed choice and shared decision-making about CRC screening options.     

Systems of support to increase colorectal cancer screening and follow-up rates (SOS): Design,challenges, and baseline characteristics of trial participants

BackgroundScreening decreases colorectal cancer (CRC) morbidity and mortality, yet remains underutilized. Screening breakdowns arise from lack of uptake and failure to follow-up after a positive screening test.ObjectivesSystems of support to increase colorectal cancer screening and follow-up (SOS) is a randomized trial designed to increase: (1) CRC screening and (2) follow-up of positive screening tests. The Chronic Care Model and the Preventive Health Model inform study design.MethodsThe setting is a large nonprofit healthcare organization. In part-1 study, patients age 50–75 due for CRC screening are randomized to one of 4 study conditions. Arm 1 receives usual care. Arm 2 receives automated support (mailed information about screening choices and fecal occult blood tests (FOBT)). Arm 3 receives automated and assisted support (a medical assistant telephone call). Arm 4 receives automated, assisted, and care management support (a registered nurse provides behavioral activation and coordination of care). In part-2, study patients with a positive FOBT or adenomas on flexible sigmoidoscopy are randomized to receive either usual care or nurse care management. Primary outcomes are: 1) the proportion with CRC screening, 2) the proportion with a complete diagnostic evaluation after a positive screening test.ResultsWe sent recruitment letters to 15,414 patients and 4675 were randomized. Randomly assigned treatment groups were similar in age, sex, race, education, self-reported health, and CRC screening history.ConclusionsWe will determine the effectiveness and cost effectiveness of stepped increases in systems of support to increase CRC screening and follow-up after a positive screening test over 2 years.     

Patient randomized trial of a targeted navigation program to improve rates of follow-up colonoscopy in community health centers

BackgroundColorectal cancer (CRC) screening by annual fecal immunochemical test (FIT) is an accessible and cost-effective strategy to lower CRC incidence and mortality. However, this mode of screening depends on follow-up colonoscopy after a positive FIT result. Unfortunately, nearly one-half of FIT-positive patients fail to complete this essential screening component. Patient navigation may improve follow-up colonoscopy adherence. To deliver patient navigation cost-effectively, health centers could target navigation to patients who are unlikely to complete the procedure on their own.ObjectivesThe Predicting and Addressing Colonoscopy Non-adherence in Community Settings (PRECISE) clinical trial will validate a risk model of follow-up colonoscopy adherence and test whether patient navigation raises rates of colonoscopy adherence overall and among patients in each probability stratum (low, moderate, and high probability of adherence without intervention).MethodsPRECISE is a collaboration with a large community health center whose patient population is 37% Latino. Eligible patients will be aged 50–75, have an abnormal FIT result in the past month, and be due for a follow-up colonoscopy. Patients will be randomized to patient navigation or usual care. Primary outcomes will be colonoscopy completion within one year of a positive FIT result, cost, and cost-effectiveness. Secondary outcomes will include time to colonoscopy receipt, adequacy of bowel prep, and communication of results to primary care providers. Primary and secondary outcomes will be reported overall and by probability stratum.DiscussionThis innovative clinical trial will test the effectiveness and financial feasibility of using a precision health intervention to improve CRC screening completion in community health centers.Trial RegistrationNational Clinical Trial (NCT) Identifier: NCT03925883.     

l-Arginine as a factor increasing arginase significance in diagnosis of primary and metastatic colorectal cancer

ObjectiveThe usefulness of simultaneous l-arginine and arginase determination in diagnosis of primary and metastatic colorectal cancer.Methodsl-Arginine and arginase were determined before and after surgery in serum from 43 patients with colorectal cancer (CRC), 24 with colorectal cancer liver metastasis (CRCLM), and 39 control subjects (10 patients with non-malignant diseases and 29 healthy blood donors).ResultsPreoperative l-arginine concentration in the patient groups was 2-fold higher, whereas arginase activity was over 3- and 6-fold higher in CRC and CRCLM when compared with control. The values of both parameters lowered significantly after surgery. The sensitivity of single parameter in CRC was 79% for l-arginine and 81% for arginase, and in CRCLM it was 83% for each parameter. The combination of l-arginine with arginase improved the sensitivity to 93% and 100% in CRC and CRCLM, respectively. The specificity of l-arginine and arginase calculated for 39 subjects was 87% and 82%.ConclusionSimultaneous determination of l-arginine and arginase increases the value of arginase itself in diagnosis and follow up of patients with CRC and CRCLM.     

Is fecal occult blood testing more sensitive for left- versus right-sided colorectal neoplasia? A systematic literature review

Owing to its slow development from removable precursor lesions and early cancer stages with good prognosis, screening for colorectal cancer holds potential to reduce both the incidence and mortality of the disease. While sigmoidoscopy only detects left-sided neoplasia, there is accumulating evidence that colonoscopy is also more effective in protecting from neoplasia in the left versus the right colon and rectum. In this context, it is an important question whether the sensitivity of the most common noninvasive screening tool for colorectal cancer, fecal occult blood testing (FOBT), also differs for left- versus right-sided neoplasia. Therefore, we systematically searched the literature for prospective screening studies conducted in average-risk adults that performed FOBT (immunochemical and/or guaiac-based) and colonoscopy among all participants, and reported site-specific sensitivities of FOBT for advanced colorectal neoplasia. Most of the seven included studies showed a higher sensitivity of FOBT for advanced neoplasia in the left versus right colon, but this finding needs to be confirmed since the available literature is scarce and not entirely consistent.     

Risk of Colorectal Cancer After Colonoscopy Compared With Flexible Sigmoidoscopy or No Lower Endoscopy Among Older Patients in the United States, 1998-2005

ObjectiveTo determine whether the risk of colorectal cancer (CRC) decreases after colonoscopy compared with sigmoidoscopy or no lower endoscopy.Patients and MethodsPatients 67 to 80 years old in the 5% random Medicare sample of the Surveillance, Epidemiology and End Results and Medicare–linked database were grouped into those who underwent colonoscopy or flexible sigmoidoscopy from January 1, 1998, through December 31, 2002, and those who did not undergo lower endoscopy. We excluded patients with inflammatory bowel disease, history of colon polyps, or family history of CRC. All patients were followed up until the diagnosis of CRC or carcinoma in situ, death, or December 31, 2005. The risk of CRC after colonoscopy was compared with the risk after sigmoidoscopy or no lower endoscopy. The multivariate Cox proportional hazards model was used in statistical analysis.ResultsIn the colonoscopy group (n=12,266), 58 CRCs (0.5%) were diagnosed during follow-up compared with 66 CRCs (1.0%) in the sigmoidoscopy group (n=6402) and 634 (1.5%) in the control group (n=41,410) (all P<.001). In the sigmoidoscopy group, 771 patients (12.0%) underwent colonoscopy within the next 12 months. In multivariate Cox regressions, colonoscopy was associated with a decreased risk of distal CRC (hazard ratio [HR], 0.266; 95% CI, 0.161-0.437) and proximal CRC (HR, 0.451; 95% CI, 0.305-0.666); sigmoidoscopy was associated with a decreased risk of distal CRC (HR, 0.409; 95% CI, 0.207-0.809) but not proximal CRC.ConclusionAmong older patients, the risk of distal CRC decreased after both colonoscopy and sigmoidoscopy; the risk of proximal CRC decreased after colonoscopy but not sigmoidoscopy.     

CT结肠成像的临床应用

CT结肠成像(CTC),也叫仿真结肠镜,是一种安全、非侵入性的结肠检查方法.临床主要应用于结、直肠癌筛查,结肠镜未完成之后的补充检查,结肠镜检查禁忌或不愿接受结肠镜检查以及结、直肠癌的诊断与分期等.本文对CTC的临床应用予以综述.     

Tests and investigations for colorectal cancer screening

Worldwide, colorectal (CRC) is the third most common form of cancer, after lung and breast cancer, and the fourth most common cause of cancer death, although in developed countries CRC incidence is higher and it accounts for an even higher proportion of cancer deaths. Successful treatment of early-stage CRC confers substantial survival advantage, and there is now overwhelming evidence that screening average-risk individuals for CRC reduces the incidence and disease-specific mortality. In spite of considerable research for new biomarkers for CRC, the detection of blood in faeces remains the most effective screening tool. The best evidence to date for population-based CRC screening comes from randomised-controlled trials that used a guaiac-based faecal occult blood test (gFOBt) as the first-line screening modality, whereby test-positive individuals are referred for follow-up investigations, usually colonoscopy. A major innovation in the last ten years or so has been the development of other more analytically sensitive and specific screening techniques for blood in faeces. The faecal immunochemical test for haemoglobin (FIT) confers substantial benefits over gFOBt in terms of analytical sensitivity, specificity and practicality and FIT are now recommended for CRC screening by the European guidelines for quality assurance in colorectal cancer screening and diagnosis. The challenge internationally is to develop high quality CRC screening programmes for which uptake is high. This is especially important for developing countries witnessing an increase in the incidence of CRC as populations adopt more westernised lifestyles.This review describes the tests available for CRC screening and how they are being used worldwide. The reader will gain an understanding of developments in CRC screening and issues that arise in choosing the most appropriate screening test (or tests) for organised population-based screening internationally and optimising the performance of the chosen test (or tests). Whilst a wide range of literature has been cited, this is not a systematic review. The authors provide FOBT CRC screening for a population of 14.6 million in the south of England and the senior author (SPH) was the lead author of the European guidelines for quality assurance in colorectal cancer screening and diagnosis and leads the World Endoscopy Organization Colorectal Cancer Committee’s Expert Working Group on ‘FIT for Screening’.