Long-term risk of colorectal cancer after screen-detected adenoma: Experiences from a Danish gFOBT-positive screening cohort

Fecal occult blood test (FOBT) screening for colorectal cancer (CRC) is implemented in several countries. Approximately half of all FOBT-positive persons have screen-detected adenomas. Despite removal of these, patients with large/multiple adenomas have increased risk of later developing new advanced adenomas and CRC. International guidelines exist for colonoscopic surveillance following adenoma removal. These divide patients into low-, intermediate- and high-risk groups. We followed 711 FOBT-positive patients with screening adenoma identified during population-based CRC screening in two Danish counties in 2005–2006. As reference population, we included 1,240,348 persons in the same age group from the rest of Denmark not included in the screening. We estimated the long-term CRC risk stratified by adenoma findings during screening and compared to the reference group. After 12 years follow-up, the CRC incidence among all adenoma patients was 322 cases per 100,000 person-years (95% confidence interval [CI]: 212–489) ranging from 251 (95% CI: 94–671) to 542 (95% CI: 300–978) cases per 100,000 person-years in the low- and high-risk groups, respectively. In the reference population, the CRC incidence was 244 (95% CI: 242–247) per 100,000. Patients with screen-detected high-risk adenomas after a positive FOBT had an almost doubled risk of CRC compared to the reference population (adjusted hazard ratio [aHR] 1.95, 95% CI: 1.08–3.51), and the incidence in those with no follow-up visits was over 3.6 (aHR 3.64, 95% CI: 1.82–7.29) times the incidence in the reference population. The increased CRC risk could be controlled if high-risk patients underwent follow-up colonoscopy (aHR 0.87, 95% CI: 0.28–2.69).     

Changes in colorectal cancer screening use after introduction of alternative screening offer in Germany: Prospective cohort study

In October 2002, screening colonoscopy was added to the German colorectal cancer (CRC) screening program as an alternative to fecal occult blood test (FOBT). We aimed to evaluate the change in CRC screening use after introduction of the dual screening offer and to assess determinants of screening use. Data were drawn from a population-based cohort study initiated during 2000–2002 in Germany (n = 5,845, age range at recruitment: 50–75 years). We conducted both cross-sectional and longitudinal analyses to obtain uptake rates of CRC screening based on four waves of data. Age-group specific proportions of participants having had FOBT within 2 years remained essentially unchanged at 61–67% between 2000 and 2002 (1st wave) and 2005–2007 (3rd wave). The proportions of participants having undergone screening colonoscopy within 10 years increased from 23–29% to 46–57%, leading to a substantial overall increase in being up-to-date with CRC screening from 66–68% to 77–80%. In 2008–2010 (4th wave), FOBT use declined and colonoscopy use continued to increase. Obesity was significantly associated with lower prevalence of being up-to-date with FOBT (odds ratio [OR] at 8-year follow-up 0.68; 95% confidence interval [CI], 0.58–0.80) and screening colonoscopy (OR, 0.73; 95% CI, 0.62–0.86). Also, smokers were less likely to have ever used FOBT (OR, 0.54; 95% CI, 0.40–0.75) or colonoscopy (OR, 0.75; 95% CI, 0.63–0.90) compared to nonsmokers. After the introduction of dual screening offer, the overall adherence to CRC screening steeply increased, mainly due to an increase in screening colonoscopy uptake. Screening tests kept being underused by obese people and smokers who are at elevated CRC risk.     

Adding familial risk assessment to faecal occult blood test can increase the effectiveness of population-based colorectal cancer screening

Background

The Dutch Health Council recently recommended the introduction of a colorectal cancer (CRC) screening programme by faecal occult blood testing (FOBT) for individuals aged 55-75 at population risk of CRC. Individuals at an increased familial CRC risk (?2 times population risk) should be identified at a younger age, so they and their relatives can receive earlier, more intensive surveillance instead of FOBT.

Aims

To determine the percentage of participants with a positive FOBT in a CRC screening programme with an increased familial CRC risk.

Methods

In a population-based study, 10,569 individuals aged 50-75 received an FOBT. Individuals with a positive FOBT were invited for colonoscopy and familial risk assessment. Participants with an average familial CRC risk were compared to those with an increased risk. Increased familial CRC risk was defined as a cumulative lifetime risk of CRC of at least 10%.

Results

Of 6001 participants, 430 had a positive FOBT, of whom 324 (63% males; mean age 63 years) completed colonoscopy and familial risk assessment. CRC (n = 22) and/or advanced adenomas (n = 122) were found in 133 participants. Familial CRC risk was increased in 6% of participants with a positive FOBT. No significant differences were found between participants with an average versus an increased familial CRC risk.

Conclusion

Six percent of participants with a positive FOBT had an increased familial CRC risk. Identifying at-risk participants enables them and their relatives to undergo regular colonoscopies. Adding familial risk assessment to FOBT screening may thus prevent a substantial number of CRCs.     

A higher detection rate for colorectal cancer and advanced adenomatous polyp for screening with immunochemical fecal occult blood test than guaiac fecal occult blood test,despite lower compliance rate. A prospective,controlled, feasibility study

Immunochemical fecal occult blood test (FIT) is a new colorectal cancer (CRC) screening method already recommended by the American screening guidelines. We aimed to test the feasibility of FIT as compared to guaiac fecal occult blood test (G‐FOBT) in a large urban population of Tel Aviv. Average‐risk persons, aged 50–75 years, were offered FIT or G‐FOBT after randomization according to the socioeconomic status of their clinics. Participants with positive tests underwent colonoscopy. Participants were followed through the Cancer Registry 2 years after the study. Hemoccult SENSA? and OC‐MICRO? (three samples, 70 ng/ml threshold) were used. FIT was offered to 4,657 persons (Group A) and G‐FOBT to 7,880 persons (Group B). Participation rate was 25.9% and 28.8% in Group A and B, respectively (p < 0.001). Positivity rate in Group A and B was 12.7% and 3.9%, respectively (p < 0.001). Cancer found in six (0.49%) and eight (0.35%) patients of Group A and B, respectively (NS). Cancer registry follow‐up found missed cancer in five (0.22%) cases of Group B and none in Group A (NS). The sensitivity, specificity, negative and positive predictive value for cancer in Group A and B were 100%, 85.9%, 100%, 3.9% and 61.5%, 96.4%, 99.8%, 9.1%, respectively. There was increased detection of advanced adenomatous polyp (AAP) by FIT, irrespective of age, gender, and socioeconomic status (Per Protocol: odds ratio 2.69, 95% confidence interval 1.6–4.5; Intention to Screen: odds ratio 3.16, 95% confidence interval 1.8–5.4). FIT is feasible in urban, average‐risk population, which significantly improved performance for detection of AAP and CRC, despite reduced participation.     

A pilot study of participation in faecal occult blood testing and screening colonoscopy after health education in Hong Kong.

Colorectal cancer is the second commonest cancer in Hong Kong. The screening behaviour of the Chinese population has not been assessed. The aim of this study is to report a pilot study of educating and subsequent evaluation of colorectal cancer screening behaviour in the Hong Kong Chinese population. Subjects were invited to attend a free health talk on colorectal cancer. Both self-paid faecal occult blood testing (FOBT) and free screening colonoscopy were offered after the education programme. Of the participants taking part in the education programme 113/119 (95%) completed the FOBT. Of the FOBT 8/113 (7%) showed positive result and three patients had neoplasia at colonoscopy. Twenty-five patients with negative FOBT also completed colonoscopy; two had adenomas. Screening colonoscopy after FOBT was accepted by 28% of subjects. Those younger than 65 years and those with a positive FOBT (7/8 versus 25/105 for those with negative FOBT, P=0.0003) were more likely to agree to screening colonoscopy. In conclusion, health education is important for ensuring high acceptance and implementation of colorectal cancer screening in Hong Kong Chinese. FOBT is an acceptable and feasible screening method in Hong Kong.     

Use of faecal markers in screening for colorectal neoplasia: a European group on tumor markers position paper

Several randomized controlled trials have shown that population‐based screening using faecal occult blood testing (FOBT) can reduce mortality from colorectal neoplasia. Based on this evidence, a number of countries have introduced screening for colorectal cancer (CRC) and high‐risk adenoma and many others are considering its introduction. The aim of this article is to critically review the current status of faecal markers as population‐based screening tests for these neoplasia. Most of the available faecal tests involve the measurement of either occult blood or a panel of DNA markers. Occult blood may be measured using either the guaiac faecal occult blood test (gFOBT) or a faecal immunochemical test (iFOBT). Although iFOBT may require a greater initial investment, they have several advantages over gFOBT, including greater analytical sensitivity and specificity. Their use results in improved clinical performance and higher uptake rates. Importantly for population screening, some of the iFOBTs can be automated and provide an adjustable cutoff for faecal haemoglobin concentration. However, samples for iFOBT, may be less stable after collection than for gFOBT. For new centres undertaking FOBT for colorectal neoplasia, the European Group on Tumour Markers recommends use of a quantitative iFOBT with an adjustable cutoff point and high throughput analysis. All participants with positive FOBT results should be offered colonoscopy. The panel recommends further research into increasing the stability of iFOBT and the development of improved and affordable DNA and proteomic‐based tests, which reduce current false negative rates, simplify sample transport and enable automated analysis.     

上海市宝山地区社区居民大肠癌筛查结果分析

目的:分析上海市宝山地区社区居民大肠癌筛查结果,探究国内大肠癌筛查模式在大肠癌诊断中的临床意义.方法:选取2017年06月至2019年06月上海市宝山地区按照社区大肠癌筛查流程完成筛查且评定为初筛阳性,并至我院完成全结肠镜诊断性检查且获取检查结果的人群作为研究对象,共769例.根据肠镜结果,分成病变组和正常组,分析两组...     

Family history and the risk of colorectal cancer: The importance of patients' history of colonoscopy

Registry‐based studies on the risk of colorectal cancer (CRC) for persons with a family history (FH) typically did not control for important covariates, such as history of colonoscopy. We aimed to quantify the association between FH and CRC risk, carefully accounting for potential confounders. We conducted a population‐based case–control study in Germany. A total of 4,313 patients with a first diagnosis of CRC (cases) and 3,153 controls recruited from 2003 to 2014 were included. We used multiple logistic regression analyses to assess the association between FH and risk of CRC with odds ratios (OR) and the resulting 95% confidence intervals (95% CI). A total of 582 cases (13.5%) and 321 (10.2%) controls reported a history of CRC in a first‐degree relative, which was associated with a 41% increase in risk of CRC (OR: 1.41, 95% CI 1.22–1.63) after adjustment for sex and age. The OR substantially increased to 1.73 (95% CI, 1.48–2.03) after comprehensive adjustment including previous colonoscopies. Irrespective of their FH status, persons with history of colonoscopies had a lower CRC risk compared with persons without previous colonoscopies and without family history (OR: 0.25, 95% CI, 0.22–0.28 for persons without FH and OR 0.45, 95% CI, 0.36–0.56 for persons with FH). In an era of widespread use of colonoscopy, adjusting for previous colonoscopy is therefore crucial for deriving valid estimates of FH‐related CRC risk. Colonoscopy reduces the risk of CRC among those with FH far below levels of people with no FH and no colonoscopy.     

Immunochemical testing of individuals positive for guaiac faecal occult blood test in a screening programme for colorectal cancer: an observational study

BACKGROUND: Screening for colorectal cancer by use of guaiac-based faecal occult blood tests (FOBT) reduces disease-specific mortality. However, due to imperfect specificity, about half of individuals positive for guaiac FOBT are negative for neoplasia on colonoscopy. We aimed to assess whether the testing of individuals positive for guaiac FOBT in a screening programme for colorectal cancer by use of a sensitive immunochemical FOBT could select more appropriately those who should receive colonoscopy. METHODS: We invited individuals who were guaiac FOBT positive in the second screening round of a pilot study in Scotland, UK, to give two samples, each from separate stools, for immunochemical FOBT while awaiting colonoscopy. Results were classed as: both samples negative (N/N), one sample negative and one positive (N/P), and both samples positive (P/P); data were assessed for sampling bias. We compared immunochemical findings with those from colonoscopy using odds ratios of positive samples (P/P) versus negative (N/N and N/P). Sensitivity, specificity, and positive and negative likelihood ratios for cancer, and for cancer and high-risk adenomatous polyps were also calculated. FINDINGS: 1486 participants were invited and 801 (54%) sets of duplicate samples were returned. We found no evidence of sampling bias with regard to sex, age, or degree of positivity on guaiac FOBT. Of 800 sets returned with consent and analysed, 173 (22%) were N/N, 129 (16%) were N/P, and 498 (62%) were P/P. Chi2 test showed a highly significant positive correlation between degree of positivity on guaiac FOBT and on immunochemical FOBT (p<0.003). 795 individuals had data for colonoscopy: one (<1%) of 171 N/N participants and one (<1%) of 127 N/P participants had colorectal cancer, compared with 38 (8%) of 497 P/P participants; adenomatous polyps were found in 28 (16%) N/N individuals, 24 (19%) N/P individuals, and 193 (39%) P/P individuals. Normal colonoscopy was less common in the P/P group (85 [17%]) than in the N/N (67 [39%]) and N/P (49 [39%]) groups. The odds ratio for P/P being associated with cancer was 7.57 (95% CI 1.84-31.4) and with high-risk adenomatous polyps was 3.11 (1.86-5.18). Sensitivity of a P/P result for cancer was 95.0% (81.8-99.1), and for cancer and high-risk adenomatous polyps was 90.1% (84.4-94.0); specificity was 39.5% (36.0-43.1) and 47.8% (43.9-51.8), respectively. INTERPRETATION: Immunochemical FOBT for individuals with positive guaiac FOBT could decrease substantially the number of false positives in a screening programme for colorectal cancer.     

Determinants of colorectal cancer screening behavior among Chinese Americans

Colorectal cancer (CRC) is the most commonly diagnosed cancer among Chinese Americans and is the third leading cause of cancer death in this population. The objectives of this study were to determine the rates of CRC screening (via fecal occult blood test (FOBT), flexible sigmoidoscopy (FSIG), and colonoscopy) among Chinese Americans and predictors of utilizing these screening procedures. Participants (N = 206) completed a self-administered questionnaire assessing cancer screening behaviors and beliefs about perceived risk of developing cancer and treatment efficacy. A series of logistic regressions indicated that physician recommendation to obtain CRC screening significantly predicted whether Chinese Americans undergo FOBT, FSIG, or colonoscopy screening (p < 0.001). Acculturation and perceived risk of developing CRC did not predict obtaining any of the screening procedures. FOBT was the most commonly reported screening method used by respondents (65%), followed by FSIG (54%) and colonoscopy (49%). These findings highlight the need to make physicians more aware of the impact their recommendations have in determining CRC screening behavior among Chinese Americans.     

Risk factors for metachronous colorectal cancer following a primary colorectal cancer: A prospective cohort study

Individuals diagnosed with colorectal cancer (CRC) are at risk of developing a metachronous CRC. We examined the associations between personal, tumour‐related and lifestyle risk factors, and risk of metachronous CRC. A total of 7,863 participants with incident colon or rectal cancer who were recruited in the USA, Canada and Australia to the Colon Cancer Family Registry during 1997‐2012, except those identified as high‐risk, for example, Lynch syndrome, were followed up approximately every 5 years. We estimated the risk of metachronous CRC, defined as the first new primary CRC following an interval of at least one year after the initial CRC diagnosis. Observation time started at the age at diagnosis of the initial CRC and ended at the age at diagnosis of the metachronous CRC, last contact or death whichever occurred earliest, or were censored at the age at diagnosis of any metachronous colorectal adenoma. Cox regression was used to derive hazard ratios (HRs) and 95% confidence intervals (CIs). During a mean follow‐up of 6.6 years, 142 (1.81%) metachronous CRCs were diagnosed (mean age at diagnosis 59.8; incidence 2.7/1,000 person‐years). An increased risk of metachronous CRC was associated with the presence of a synchronous CRC (HR = 2.73; 95% CI: 1.30–5.72) and the location of cancer in the proximal colon at initial diagnosis (compared with distal colon or rectum, HR = 4.16; 95% CI: 2.80–6.18). The presence of a synchronous CRC and the location of the initial CRC might be useful for deciding the intensity of surveillance colonoscopy for individuals diagnosed with CRC.     

Evaluation of a Colorectal Carcinoma Screening Program in Kota Setar and Kuala Muda Districts,Malaysia

Background: A colorectal cancer screening program was piloted in two districts of Kedah in 2013. There is scarcity of information on colorectal cancer screening in Malaysia. Objective: Thus, this research was conducted to evaluate the colorectal cancer screening program in the districts to provide insights intop its efficacy. Materials and Methods: A cross sectional study was conducted using data on the colorectal cancer screening program in 2013 involving Kota Setar and Kuala Muda districts in Malaysia. We determined the response rate of immunochemical fecal occult blood test (iFOBT), colonoscopy compliance, and detection rates of neoplasia and carcinoma. We also compared the response of FOBT by demographic background. Results: The response rate of FOBT for first iFOBT screening was 94.7% while the second iFOBT screening was 90.7%. Participants from Kuala Muda district were 27 times more likely to default while Indians had a 3 times higher risk of default compared to Malays. The colonoscopy compliance was suboptimal among those with positive iFOBT. The most common finding from colonoscopy was hemorrhoids, followed by tubular adenoma. Detection rate of carcinoma and neoplasia for our program was 1.2%. Conclusions: In summary, the response rate of iFOBT was encouraging but the colonoscopy compliance was suboptimal which led to a considerably low detection rate.     

Development of new non‐invasive tests for colorectal cancer screening: The relevance of information on adenoma detection

Researchers are actively pursuing the development of a new non‐invasive test (NIT) for colorectal cancer (CRC) screening as an alternative to fecal occult blood tests (FOBTs). The majority of pilot studies focus on the detection of invasive CRC rather than precursor lesions (i.e., adenomas). We aimed to explore the relevance of adenoma detection for the viability of an NIT for CRC screening by considering a hypothetical test that does not detect adenomas beyond chance. We used the Simulation Model of Colorectal Cancer (SimCRC) to estimate the effectiveness of CRC screening and the lifetime costs (payers' perspective) for a cohort of US 50‐years‐old persons to whom CRC screening is offered from age 50–75. We compared annual screening with guaiac and immunochemical FOBTs (with sensitivities up to 70 and 24% for CRC and adenomas, respectively) to annual screening with a hypothetical NIT (sensitivity of 90% for CRC, no detection of adenomas beyond chance, specificity and cost similar to FOBTs). Screening with the NIT was not more effective, but was 29–44% more costly than screening with FOBTs. The findings were robust to varying the screening interval, the NIT's sensitivity for CRC, adherence rates favoring the NIT, and the NIT's unit cost. A comparative modelling approach using a model that assumes a shorter adenoma dwell time (MISCAN‐COLON) confirmed the superiority of the immunochemical FOBT over an NIT with no ability to detect adenomas. Information on adenoma detection is crucial to determine whether a new NIT is a viable alternative to FOBTs for CRC screening. Current evidence thus lacks an important piece of information to identify marker candidates that hold real promise and deserve further (large‐scale) evaluation.     

Agreement between self‐reported and registered colorectal cancer screening: a meta‐analysis

This random‐effects meta‐analysis investigates the accuracy of self‐reported colorectal cancer screening history as a function of screening mode (colonoscopy, flexible sigmoidoscopy, faecal occult blood testing – FOBT, double‐contrast barium enema – DCBE) and survey mode (written, telephone, face‐to‐face). Summary estimates of sensitivity, specificity, positive predictive value (PPV) and area under the receiver operating characteristic curve (AUC) were calculated. Medical record data were used as reference. We included 23 studies comprising 11 592 subjects. Colonoscopy yielded higher AUC [0.948, 95% confidence interval (CI) = 0.918, 0.968] than flexible sigmoidoscopy (0.883, 95% CI = 0.849, 0.911) and FOBT (0.869, 95% CI = 0.833, 0.898). Colonoscopy showed the highest sensitivity (0.888, 95% CI = 0.835, 0.931), whereas specificity was comparable between screening modes (ranging from 0.802 for FOBT to 0.904 for DCBE). AUC was not significantly different between survey modes. Prevalence of screening history correlated positively with sensitivity and negatively with specificity, possibly because of errors in the medical records. In conclusion, the accuracy of self‐reported cancer screening is generally moderate, and higher for colonoscopy than for sigmoidoscopy and FOBT.     

Predictors of colorectal cancer screening from patients enrolled in a managed care health plan

BACKGROUND: Despite the growing recognition of the importance of colorectal cancer (CRC) screening in reducing cancer mortality, national screening rates are low, indicating a critical need to understand the barriers and remedies for underutilization of CRC screening tests. METHODS: Using results from independent cross-sectional telephone surveys with patients aged>or=50 years performed before (2000; n=498) and after (2003; n=482) a quality improvement intervention for CRC screening within a large managed care health plan, the trends and predictors of CRC screening with fecal occult blood test (FOBT) and/or endoscopy (flexible sigmoidoscopy/colonoscopy) were examined from a patient perspective. RESULTS: In 2000, patient reported screening rates within guidelines were 38% for any test, 23% for endoscopy, and 22% for FOBT. In 2003, screening rates increased to 50% for any test, 39% for endoscopy, and 24% for FOBT. Having discussed CRC with a doctor significantly increased the odds of being screened (FOBT: odds ratio [OR], 2.09 [95% confidence interval (95% CI), 1.47-2.96]; endoscopy: OR, 2.33 [95% CI, 1.67-3.26]; and any test: OR, 2.86 [95% CI, 2.06-3.96]), and reporting barriers to CRC in general decreased the odds of being screened (FOBT: OR, 0.76 [95% CI, 0.60-0.95]; endoscopy: OR, 0.74 [95% CI, 0.60-0.92]; and any test: OR, 0.66 [95% CI, 0.54-0.80]). CONCLUSIONS: Although screening rates increased over the 3-year period, evidence was found of ongoing underutilization of CRC screening. The 2 strongest determinants of obtaining CRC screening were provider influence and patient barriers related to CRC screening in general, pointing to the need for multilevel interventions that target both the provider and patient.     

Men with negative results of guaiac‐based fecal occult blood test have higher prevalences of colorectal neoplasms than women with positive results

Guaiac‐based fecal occult blood tests (gFOBTs) are the most commonly applied tests for colorectal cancer screening globally but have relatively poor sensitivity to detect colorectal neoplasms. Men have higher prevalences of colorectal neoplasms than women. In case of a positive gFOBT result, participants are referred to colonoscopy, independent of sex. To assess performance of gFOBT in routine screening practice, we assessed age and sex specific prevalences (age groups: 55–59, 60–64, 65–69 and 70–74) of colorectal neoplasms in 182,956 women and men undergoing colonoscopy for primary screening and in 20,884 women and men undergoing colonoscopy to follow‐up a positive gFOBT in Bavaria, Germany, in 2007–2009. We conducted model calculations to estimate prevalences among gFOBT negative individuals. Analogous model calculations were performed for women and men tested positive or negative with fecal immunochemical tests. In all age groups (55–59, 60–64, 65–69 and 70–74 years), men undergoing colonoscopy for primary screening had substantially higher prevalences of any colorectal neoplasms and essentially the same prevalences of advanced colorectal neoplasms compared to women undergoing colonoscopy to follow‐up a positive gFOBT. Model calculations suggest that men with negative gFOBT likewise have substantially higher prevalences of colorectal neoplasms than gFOBT positive women in each age group. Model calculations further indicate that no such sex paradoxon occurs, and a much clearer risk stratification can be achieved with fecal immunochemical tests. Our findings underline need to move forward from and overcome shortcomings of gFOBT‐based colorectal cancer screening.     

Accuracy of Self-Checked Fecal Occult Blood Testing for Colorectal Cancer in Thai Patients

Purpose: Colorectal cancer (CRC) screening with fecal occult blood testing (FOBT) has been associatedwith a reduction in CRC incidence and CRC-related mortality. However, a conventional FOBT requires stoolcollection and handling, which may be inconvenient for participants. The EZ-DetectTM (Siam PharmaceuticalThailand) is a FDA-approved chromogen-substrate based FOBT which is basically a self-checked FOBT (nostool handling required). This study aimed to evaluate the accuracy of EZ-Detect for CRC detection. Methods:This prospective study was conducted in the Faculty of Medicine, Siriraj Hospital, Bangkok, Thailand betweenNovember 2013 and May 2014. Some 96 patients with histologically-proven CRC and 101 patients with normalcolonoscopic findings were invited to perform self-checked FOBT according to the manufacturer’s instructions.Results were compared with endoscopic and pathologic findings. Sensitivity, specificity, positive predictive value(PPV), and negative predictive value (NPV) for CRC detection were calculated. Results: The present studyrevealed the sensitivity, specificity, PPV and NPV of this self-checked FOBT for CRC detection to be 41% (95%CI: 31-51), 97% (95% CI: 92-99), 93% (95% CI: 81-98) and 63% (95% CI: 55-70), respectively. The overallaccuracy of the self-checked FOBT for identifying CRC was 70%. The sensitivity for CRC detection based on7th AJCC staging was 29% for stage I, 32% for stage II and 50% for stage III/IV (P=0.19). The sensitivity was33% for proximal colon and 42% for distal colon and rectal cancer (P=0.76). Notably, none of nine infiltrativelesions gave a positive FOBT. Conclusions: The self-checked FOBT had an acceptable accuracy of CRC detectionexcept for infiltrative tumors. This home-administrated or ‘DIY’ do-it-yourself FOBT could be considered asone non-invasive and convenient tool for CRC screening.     

结直肠癌患者血浆Septin9 DNA甲基化联合FOBT检测的临床应用价值

目的:探讨血浆Septin9 DNA甲基化及粪便隐血试验（FOBT）在结直肠癌（CRC）诊断中的应用价值。方法:回顾性收集2017年6月至2022年1月我院收治并经病理检查确诊的101例结直肠良性腺瘤患者、209例结直肠癌患者分别作为良性腺瘤组和结直肠癌组，选取同期在我院进行体检的98例健康人群作为正常对照组，比较三组一般资料及血浆Septin9 DNA甲基化及FOBT阳性情况，比较不同病理特征、不同临床分期结直肠癌患者血浆Septin9 DNA甲基化、FOBT阳性情况，采用受试者工作曲线（ROC）评估血浆Septin9 DNA甲基化、FOBT单项及联合检测对结直肠癌的诊断价值。结果:三组血浆Septin9 DNA甲基化、FOBT阳性率比较，结直肠癌组高于良性腺瘤组及正常对照组，良性腺瘤组高于正常对照组（P<0.05）；肿瘤低分化、淋巴结转移、脉管/神经侵犯的结直肠癌患者血浆Septin9 DNA甲基化和FOBT阳性率高于肿瘤高分化、中分化及未发生淋巴结转移、未发生脉管/神经侵犯的结直肠癌患者（P<0.05）；随着结直肠癌TNM临床分期升高，血浆Septin9 DNA甲基化及FOBT阳性率升高，差异具有统计学意义（P<0.05）；血浆Septin9 DNA甲基化和FOBT联合诊断结直肠癌的敏感度、曲线下面积（AUC）（87.08%、0.885）均高于两者单独诊断（59.33%、0.744和52.63%、0.643，P<0.05）；血浆Septin9 DNA甲基化诊断结直肠癌的特异度、阳性预测值和阴性预测值分别为89.45%、85.52%和67.68%；FOBT分别为76.38%、70.06%和60.56%，两者联合诊断分别为89.95%、90.10%和86.89%。联合诊断优于单项诊断。结论:随着结直肠病变恶性程度的增加，血浆Septin9 DNA甲基化和FOBT阳性率升高，血浆Septin9 DNA甲基化、FOBT联合检测对结直肠癌具有较高的诊断价值，可作为结直肠癌的实验室诊断指标。     

厦门市海沧区结直肠癌筛查结果分析

目的通过分析厦门市海沧区结直肠癌的筛查结果,探索筛查的结直肠癌最佳方案,以期达到对结直肠肿瘤的早发现、早诊断和早治疗。方法 自2008年12月—2010年10月,采用中国癌症基金会推荐的结直肠癌筛查方案,对海沧区4个行政村40~74岁常住居民结合问卷调查和连续粪便隐血试验(Fecal occult blood test,FOBT)进行初筛,共8179人,实际接受筛查6380人。高危人群接受全结肠镜检查。结果 经问卷调查和FOBT检测,获得结直肠癌高危人群1035例。81.06%的高危者接受全结肠镜检查,结直肠癌和腺瘤息肉及其他病变检出率分别为1.67%和23.96%。问卷调查及FOBT均阳性者结直肠癌检出率显著高于单纯问卷调查阳性者或单纯FOBT阳性者(P＜0.05);FOBT两次阳性者结直肠癌检出率显著高于FOBT阴性和FOBT单次阳性检出率(P＜0.05)。FOBT检测阳性次数与结直肠癌检出率和腺瘤息肉及其他病变检出率呈线性关系(P＜0.05)。结论 调查问卷和连续粪便隐血试验筛查可明显缩小高危人群,大大降低筛查的工作量。     

How should individuals with a false‐positive fecal occult blood test for colorectal cancer be managed? A decision analysis

Several industrialized nations recommend fecal occult blood testing (FOBT) to screen for colorectal cancer (CRC), but corresponding screening guidelines do not specify how individuals with a prior false-positive FOBT result (fpFOBT) should be managed in terms of subsequent CRC screening. Accordingly, we conducted a decision analysis to compare different strategies for managing such individuals. We used a previously developed CRC microsimulation model, SimCRC, to calculate life-years and the lifetime number of colonoscopies (as a measure of required resources) for a cohort of 50-year-olds to whom FOBT-based CRC screening is offered annually from 50 to 75 years. We compared three management strategies for individuals with a prior fpFOBT: (i) resume screening in 10 years with 10-yearly colonoscopy (SwitchCol_long); (ii) resume screening in 1 year with annual FOBT (ContinueFOBT_Short) and (iii) resume screening in 10 years (i.e., the recommended interval following a negative colonscopy) with annual FOBT (ContinueFOBT_long). We performed sensitivity analyses on various parameters and assumptions. When using different management strategies for individuals with a prior fpFOBT, the variation in the number of life-years gained relative to no screening was <2%, whereas the variation in the lifetime number of colonoscopies was 23% (percentages are calculated as the maximum difference across strategies divided by the lowest number across strategies). The ContinueFOBT_long strategy showed the lowest lifetime number of colonoscopies per life-year gained even when key assumptions were varied. In conclusion, the ContinueFOBT_long strategy was advantageous regarding both clinical benefit and required resources. Specifying an appropriate management strategy for individuals with a prior fpFOBT may substantially reduce required resources within a FOBT-based CRC screening program without limiting its effectiveness.