Colonoscopy surveillance following adenoma removal to reduce the risk of colorectal cancer: a retrospective cohort study.

BACKGROUND: Colonoscopy surveillance is recommended for some patients post polypectomy. The 2002 UK surveillance guidelines classify post-polypectomy patients into low, intermediate and high risk, and recommend different strategies for each classification. Limited evidence supports these guidelines. OBJECTIVES: To examine, for each risk group, long-term colorectal cancer incidence by baseline characteristics and the number of surveillance visits; the effects of interval length on detection rates of advanced adenomas and colorectal cancer at first surveillance; and the cost-effectiveness of surveillance compared with no surveillance. DESIGN: A retrospective cohort study and economic evaluation. SETTING: Seventeen NHS hospitals. PARTICIPANTS: Patients with a colonoscopy and at least one adenoma at baseline. MAIN OUTCOME MEASURES: Long-term colorectal cancer incidence after baseline and detection rates of advanced adenomas and colorectal cancer at first surveillance. DATA SOURCES: Hospital databases, NHS Digital, the Office for National Statistics, National Services Scotland and Public Health England. METHODS: Cox regression was used to compare colorectal cancer incidence in the presence and absence of surveillance and to identify colorectal cancer risk factors. Risk factors were used to stratify risk groups into higher- and lower-risk subgroups. We examined detection rates of advanced adenomas and colorectal cancer at first surveillance by interval length. Cost-effectiveness of surveillance compared with no surveillance was evaluated in terms of incremental costs per colorectal cancer prevented and per quality-adjusted life-year gained. RESULTS: Our study included 28,972 patients, of whom 14,401 (50%), 11,852 (41%) and 2719 (9%) were classed as low, intermediate and high risk, respectively. The median follow-up time was 9.3 years. Colorectal cancer incidence was 140, 221 and 366 per 100,000 person-years among low-, intermediate- and high-risk patients, respectively. Attendance at one surveillance visit was associated with reduced colorectal cancer incidence among low-, intermediate- and high-risk patients [hazard ratios were 0.56 (95% confidence interval 0.39 to 0.80), 0.59 (95% confidence interval 0.43 to 0.81) and 0.49 (95% confidence interval 0.29 to 0.82), respectively]. Compared with the general population, colorectal cancer incidence without surveillance was similar among low-risk patients and higher among high-risk patients [standardised incidence ratios were 0.86 (95% confidence interval 0.73 to 1.02) and 1.91 (95% confidence interval 1.39 to 2.56), respectively]. For intermediate-risk patients, standardised incidence ratios differed for the lower- (0.70, 95% confidence interval 0.48 to 0.99) and higher-risk (1.46, 95% confidence interval 1.19 to 1.78) subgroups. In each risk group, incremental costs per colorectal cancer prevented and per quality-adjusted life-year gained with surveillance were lower for the higher-risk subgroup than for the lower-risk subgroup. Incremental costs per quality-adjusted life-year gained were lowest for the higher-risk subgroup of high-risk patients at £7821. LIMITATIONS: The observational design means that we cannot assume that surveillance caused the reductions in cancer incidence. The fact that some cancer staging data were missing places uncertainty on our cost-effectiveness estimates. CONCLUSIONS: Surveillance was associated with reduced colorectal cancer incidence in all risk groups. However, in low-risk patients and the lower-risk subgroup of intermediate-risk patients, colorectal cancer incidence was no higher than in the general population without surveillance, indicating that surveillance might not be necessary. Surveillance was most cost-effective for the higher-risk subgroup of high-risk patients. FUTURE WORK: Studies should examine the clinical effectiveness and cost-effectiveness of post-polypectomy surveillance without prior classification of patients into risk groups. TRIAL REGISTRATION: This trial is registered as ISRCTN15213649. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 26. See the NIHR Journals Library website for further project information.

Bowel cancers develop from polyps, also called adenomas, which are growths on the lining of the bowel. Removal of adenomas, therefore, helps prevent bowel cancer. Adenomas can be detected and removed during colonoscopy, when a thin tube with a camera on one end is used to examine the bowel lining. In the UK, patients with adenomas are divided into three risk groups. Low-risk patients (i.e. those with one or two adenomas that are < 10 mm in size) are thought to be unlikely to develop bowel cancer after adenoma removal and follow-up colonoscopy is not recommended in this group. Intermediate-risk patients (i.e. those with three or four adenomas that are < 10 mm in size, or one or two adenomas with at least one ≥ 10 mm in size) are recommended to have another colonoscopy 3 years after adenoma removal. High-risk patients (i.e. those with five or more adenomas that are < 10 mm in size, or three or more adenomas with at least one ≥ 10 mm in size) are recommended to have another colonoscopy after 1 year and then usually again after 3 years. The number of follow-up colonoscopies carried out is stretching health-care resources and each procedure carries a small risk of complications for patients. It is possible that too many follow-up colonoscopies are being carried out. This study aimed to determine which patients require follow-up colonoscopies and how many are required to detect adenomas and prevent bowel cancer, while also being resource-efficient, cost-effective and not exposing patients to unnecessary risks. The study used data from 17 hospitals and cancer registries in the UK. In each risk group, one follow-up colonoscopy after adenoma removal was associated with a 40­50% reduction in bowel cancer risk. However, even without any follow-up, bowel cancer risk was no higher in some low- and intermediate-risk patients than in the general population. These patients may not need as many follow-up colonoscopies as recommended. In the case of higher-risk patients, who even after adenoma removal have a higher bowel cancer risk than the general population, follow-up colonoscopies are necessary and cost-effective.

Long-term colorectal cancer incidence after adenoma removal and the effects of surveillance on incidence: a multicentre, retrospective, cohort study.

OBJECTIVE: Postpolypectomy colonoscopy surveillance aims to prevent colorectal cancer (CRC). The 2002 UK surveillance guidelines define low-risk, intermediate-risk and high-risk groups, recommending different strategies for each. Evidence supporting the guidelines is limited. We examined CRC incidence and effects of surveillance on incidence among each risk group. DESIGN: Retrospective study of 33 011 patients who underwent colonoscopy with adenoma removal at 17 UK hospitals, mostly (87%) from 2000 to 2010. Patients were followed up through 2016. Cox regression with time-varying covariates was used to estimate effects of surveillance on CRC incidence adjusted for patient, procedural and polyp characteristics. Standardised incidence ratios (SIRs) compared incidence with that in the general population. RESULTS: After exclusions, 28 972 patients were available for analysis; 14 401 (50%) were classed as low-risk, 11 852 (41%) as intermediate-risk and 2719 (9%) as high-risk. Median follow-up was 9.3 years. In the low-risk, intermediate-risk and high-risk groups, CRC incidence per 100 000 person-years was 140 (95% CI 122 to 162), 221 (195 to 251) and 366 (295 to 453), respectively. CRC incidence was 40%-50% lower with a single surveillance visit than with none: hazard ratios (HRs) were 0.56 (95% CI 0.39 to 0.80), 0.59 (0.43 to 0.81) and 0.49 (0.29 to 0.82) in the low-risk, intermediate-risk and high-risk groups, respectively. Compared with the general population, CRC incidence without surveillance was similar among low-risk (SIR 0.86, 95% CI 0.73 to 1.02) and intermediate-risk (1.16, 0.97 to 1.37) patients, but higher among high-risk patients (1.91, 1.39 to 2.56). CONCLUSION: Postpolypectomy surveillance reduces CRC risk. However, even without surveillance, CRC risk in some low-risk and intermediate-risk patients is no higher than in the general population. These patients could be managed by screening rather than surveillance.

Faecal immunochemical tests versus colonoscopy for post-polypectomy surveillance: an accuracy, acceptability and economic study.

BACKGROUND: In the UK, patients with one or two adenomas, of which at least one is ≥ 10 mm in size, or three or four small adenomas, are deemed to be at intermediate risk of colorectal cancer (CRC) and referred for surveillance colonoscopy 3 years post polypectomy. However, colonoscopy is costly, can cause discomfort and carries a small risk of complications. OBJECTIVES: To determine whether or not annual faecal immunochemical tests (FITs) are effective, acceptable and cost saving compared with colonoscopy surveillance for detecting CRC and advanced adenomas (AAs). DESIGN: Diagnostic accuracy study with health psychology assessment and economic evaluation. SETTING: Participants were recruited from 30 January 2012 to 30 December 2013 within the Bowel Cancer Screening Programme in England. PARTICIPANTS: Men and women, aged 60-72 years, deemed to be at intermediate risk of CRC following adenoma removal after a positive guaiac faecal occult blood test were invited to participate. Invitees who consented and returned an analysable FIT were included. INTERVENTION: We offered participants quantitative FITs at 1, 2 and 3 years post polypectomy. Participants testing positive with any FIT were referred for colonoscopy and not offered further FITs. Participants testing negative were offered colonoscopy at 3 years post polypectomy. Acceptibility of FIT was assessed using discussion groups, questionnaires and interviews. MAIN OUTCOME MEASURES: The primary outcome was 3-year sensitivity of an annual FIT versus colonoscopy at 3 years for detecting advanced colorectal neoplasia (ACN) (CRC and/or AA). Secondary outcomes included participants' surveillance preferences, and the incremental costs and cost-effectiveness of FIT versus colonoscopy surveillance. RESULTS: Of 8008 invitees, 5946 (74.3%) consented and returned a round 1 FIT. FIT uptake in rounds 2 and 3 was 97.2% and 96.9%, respectively. With a threshold of 40 µg of haemoglobin (Hb)/g faeces (hereafter referred to as µg/g), positivity was 5.8% in round 1, declining to 4.1% in round 3. Over three rounds, 69.2% (18/26) of participants with CRC, 34.3% (152/443) with AAs and 35.6% (165/463) with ACN tested positive at 40 µg/g. Sensitivity for CRC and AAs increased, whereas specificity decreased, with lower thresholds and multiple rounds. At 40 µg/g, sensitivity and specificity of the first FIT for CRC were 30.8% and 93.9%, respectively. The programme sensitivity and specificity of three rounds at 10 µg/g were 84.6% and 70.8%, respectively. Participants' preferred surveillance strategy was 3-yearly colonoscopy plus annual FITs (57.9%), followed by annual FITs with colonoscopy in positive cases (31.5%). FIT with colonoscopy in positive cases was cheaper than 3-yearly colonoscopy (£2,633,382), varying from £485,236 (40 µg/g) to £956,602 (10 µg/g). Over 3 years, FIT surveillance could miss 291 AAs and eight CRCs using a threshold of 40 µg/g, or 189 AAs and four CRCs using a threshold of 10 µg/g. CONCLUSIONS: Annual low-threshold FIT with colonoscopy in positive cases achieved high sensitivity for CRC and would be cost saving compared with 3-yearly colonoscopy. However, at higher thresholds, this strategy could miss 15-30% of CRCs and 40-70% of AAs. Most participants preferred annual FITs plus 3-yearly colonoscopy. Further research is needed to define a clear role for FITs in surveillance. FUTURE WORK: Evaluate the impact of ACN missed by FITs on quality-adjusted life-years. TRIAL REGISTRATION: Current Controlled Trials ISRCTN18040196. FUNDING: National Institute for Health Research (NIHR) Health Technology Assessment programme, NIHR Imperial Biomedical Research Centre and the Bobby Moore Fund for Cancer Research UK. MAST Group Ltd provided FIT kits.

Faecal immunochemical tests (FIT) versus colonoscopy for surveillance after screening and polypectomy: a diagnostic accuracy and cost-effectiveness study.

OBJECTIVE: The English Bowel Cancer Screening Programme (BCSP) recommends 3 yearly colonoscopy surveillance for patients at intermediate risk of colorectal cancer (CRC) postpolypectomy (those with three to four small adenomas or one ≥10 mm). We investigated whether faecal immunochemical tests (FITs) could reduce surveillance burden on patients and endoscopy services. DESIGN: Intermediate-risk patients (60-72 years) recommended 3 yearly surveillance were recruited within the BCSP (January 2012-December 2013). FITs were offered at 1, 2 and 3 years postpolypectomy. Invitees consenting and returning a year 1 FIT were included. Participants testing positive (haemoglobin ≥40 µg/g) at years one or two were offered colonoscopy early; all others were offered colonoscopy at 3 years. Diagnostic accuracy for CRC and advanced adenomas (AAs) was estimated considering multiple tests and thresholds. We calculated incremental costs per additional AA and CRC detected by colonoscopy versus FIT surveillance. RESULTS: 74% (5938/8009) of invitees were included in our study having participated at year 1. Of these, 97% returned FITs at years 2 and 3. Three-year cumulative positivity was 13% at the 40 µg/g haemoglobin threshold and 29% at 10 µg/g. 29 participants were diagnosed with CRC and 446 with AAs. Three-year programme sensitivities for CRC and AAs were, respectively, 59% and 33% at 40 µg/g, and 72% and 57% at 10 µg/g. Incremental costs per additional AA and CRC detected by colonoscopy versus FIT (40 µg/g) surveillance were £7354 and £180 778, respectively. CONCLUSIONS: Replacing 3 yearly colonoscopy surveillance in intermediate-risk patients with annual FIT could reduce colonoscopies by 71%, significantly cut costs but could miss 30%-40% of CRCs and 40%-70% of AAs. TRIAL REGISTRATION NUMBER: ISRCTN18040196; Results.

Assessment of obesity, overweight and its association with the fast food consumption in medical students.

INTRODUCTION: Obesity is a condition in which excess body fat accumulates, which leads to various adverse effects on health, particularly cardiovascular diseases (CVDs), which reduce life expectancy and/or increase health problems. Fast food consumption is one of the factors which have been reported as a cause of obesity. Body mass index (BMI) is used to assess obesity and overweight, which can be calculated by using the formula, weight in kg, divided by square of height in metres. AIM: This study focused on the relationship of body mass index with fast food consumption, associated soft drink consumption and physical activity. METHODS: Descriptive cross-sectional study was conducted in Department of Biochemistry, SBKS MI and RC, and Sumandeep Vidyapeeth. This study was approved by the ethical review board .One hundred and forty seven medical students from 1(st) year MBBS course were included in this study. Self-structured questionnaire was used, which contained several data like information on age, height, weight, education level. The formula used for calculating BMI was, weight in kg, divided by square of height in metres (Kg/m(2)). RESULTS: In our study, out of 147 students, a total of 138 students (more than 90%) used to have fast food. Among these, a total of 47 students (34.05%) were pre-obese and obese. Out of 147 students, 87 students (59.18%) were in normal weight range, while 13 (8.84%) students were underweight. STATISTICAL ANALYSIS: Data was compiled in an Excel worksheet and it was analyzed for percentages and proportions. Chi-square and Pearson's correlation test were also applied wherever they were applicable and Alpha error was set at a 5% level. CONCLUSION: In our study, a significant relationship was found between BMI and fast food consumption, less physical activity, and intake of soft drinks.

Assessment of denitrifying bacterial composition in activated sludge.

The abundance and structure of denitrifying bacterial community in different activated sludge samples were assessed, where the abundance of denitrifying functional genes showed nirS in the range of 10(4)-10(5), nosZ with 10(4)-10(6) and 16S rRNA gene in the range 10(9)-10(10) copy number per ml of sludge. The culturable approach revealed Pseudomonas sp. and Alcaligenes sp. to be numerically high, whereas culture independent method showed betaproteobacteria to dominate the sludge samples. Comamonas sp. and Pseudomonas fluorescens isolates showed efficient denitrification, while Pseudomonas mendocina, Pseudomonas stutzeri and Brevundimonas diminuta accumulated nitrite during denitrification. Numerically dominant RFLP OTUs of the nosZ gene from the fertilizer factory sludge samples clustered with the known isolates of betaproteobacteria. The data also suggests the presence of different truncated denitrifiers with high numbers in sludge habitat.