A survey is given of colorectal polyps detected in a prospective randomized screening study with the fecal occult blood test. It is demonstrated that colonoscopy in persons with positive Hemoccult-II tests results in detection of and removal of a higher number of adenomas than among controls. The strategy may, therefore, possibly be followed by a reduction of the incidence of colorectal cancer. Screen-detected adenomas were most often in males and were larger than among controls; they were most often in the sigmoid colon, whereas the rectum was the most frequent location for adenomas in controls. Eight percent of persons with screen-detected adenomas had some symptoms, which could be referred to adenomas, in contrast to 50% among controls. Hyperplastic polyps served as markers for adenomas in persons with positive Hemoccult-II as well as in controls with adenomas detected by colonoscopy; however, most persons with adenomas had no hyperplastic polyps. Endoscopic polypectomy did not result in any severe complications, but surgical removal in 2 of 22 patients proved fatal. The results presented are compared with those of other prospective randomized trials. The optimistic view--that the incidence of cancer may be reduced by polypectomy in persons with positive Hemoccult-II tests--stresses the importance of securing optimal colonoscopy service.
Most quality indicators for colonoscopy measure processes; little is known about their relationship to patient outcomes. We investigated whether characteristics of endoscopists, determined from administrative data, are associated with development of postcolonoscopy colorectal cancer (PCCRC).
We identified individuals diagnosed with colorectal cancer in Ontario from 2000 to 2005 using the Ontario Cancer Registry. We determined performance of colonoscopy using Ontario Health Insurance Plan data. Patients who had complete colonoscopies 7 to 36 months before diagnosis were defined as having a PCCRC. Patients who had complete colonoscopies within 6 months of diagnosis had detected cancers. We determined if endoscopist factors (volume, polypectomy and completion rate, specialization, and setting) were associated with PCCRC using logistic regression, controlling for potential covariates.
In the study, 14,064 patients had a colonoscopy examination within 36 months of diagnosis; 584 (6.8%) with distal and 676 (12.4%) with proximal tumors had PCCRC. The endoscopist's specialty (nongastroenterologist/nongeneral surgeon) and setting (non-hospital-based colonoscopy) were associated with PCCRC. Those who underwent colonoscopy by an endoscopist with a high completion rate were less likely to have a PCCRC (distal: odds ratio [OR], 0.73; 95% confidence interval [CI], 0.54-0.97; P = .03; proximal: OR, 0.72; 95% CI, 0.53-0.97; P = .002). Patients with proximal cancers undergoing colonoscopy by endoscopists who performed polypectomies at high rates had a lower risk of PCCRC (OR, 0.61; 95% CI, 0.42-0.89; P
Adherence to surveillance colonoscopy guidelines is important to prevent colorectal cancer (CRC) and unnecessary workload.
To evaluate how well Canadian gastroenterologists adhere to colonoscopy surveillance guidelines after adenoma removal or treatment for CRC.
Patients with a history of adenomas or CRC who had surveillance performed between October 2008 and October 2010 were retrospectively included. Time intervals between index colonoscopy and surveillance were compared with the 2008 guideline recommendations of the American Gastroenterological Association and regarded as appropriate when the surveillance interval was within six months of the recommended time interval.
A total of 265 patients were included (52% men; mean age 58 years). Among patients with a normal index colonoscopy (n=110), 42% received surveillance on time, 38% too early (median difference = 1.2 years too early) and 20% too late (median difference = 1.0 year too late). Among patients with nonadvanced adenomas at index (n=96), 25% underwent surveillance on time, 61% too early (median difference = 1.85) and 14% too late (median difference = 1.1). Among patients with advanced neoplasia at index (n=59), 29% underwent surveillance on time, 34% too early (median difference = 1.86) and 37% later than recommended (median difference = 1.61). No significant difference in adenoma detection rates was observed when too early surveillance versus appropriate surveillance (34% versus 33%; P=0.92) and too late surveillance versus appropriate surveillance (21% versus 33%; P=0.11) were compared.
Only a minority of surveillance colonoscopies were performed according to guideline recommendations. Deviation from the guidelines did not improve the adenoma detection rate. Interventions aimed at improving adherence to surveillance guidelines are needed.
Cites: Int J Cancer. 2004 Aug 10;111(1):147-5115185356
Cites: Ann Intern Med. 2004 Aug 17;141(4):264-7115313742
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Evidence supports an association between certain colorectal adenoma characteristics and predisposition to cancer. The association between anatomical location of colorectal adenoma, age and advanced adenomas needs attention. The objective of this study was to evaluate the possible association between occurrence of sporadic advanced adenomas with location and age.
A cross-sectional study using baseline data from index colonoscopy from a randomized controlled trial evaluating chemopreventive treatment against recurrence of colorectal adenomas was performed. Inclusion criteria for patients were one adenoma of >1?cm in diameter or multiple adenomas of any size, or an adenoma of any size and familial disposition for colorectal cancer. Multivariate regression and propensity score-matched analyses were used to correlate location of adenomas and age with advanced adenoma features.
In this study, 2149 adenomas were removed in 1215 patients. Advanced colorectal adenomas primarily occurred in the anal part of the colon. Older age was associated with more adenomas and more oral occurrence of adenomas, as well as a higher risk of advanced adenomas. Surprisingly, specifically for the oral adenomas the risk of advanced adenoma seems to be lower for older patients compared with younger.
This study presents new results with regard to association between age, location of adenomas and risk of advanced adenomas. The results indicate that sigmoidoscopy for screening purposes may be obsolete, and add to the existing literature on which future guidelines for screening may be based.
Colorectal cancer (CRC) is the most common cause of non-tobacco-related cancer deaths in Canadian men and women, accounting for 10% of all cancer deaths. An estimated 7800 men and women will be diagnosed with CRC, and 3250 will die from the disease in Ontario in 2007. Given that CRC incidence and mortality rates in Ontario are among the highest in the world, the best opportunity to reduce this burden of disease would be through screening. The present report describes the findings and recommendations of Cancer Care Ontario's Colonoscopy Standards Expert Panel, which was convened in March 2006 by the Program in Evidence-Based Care. The recommendations will form the basis of the quality assurance program for colonoscopy delivered in support of Ontario's CRC screening program.
Cites: N Engl J Med. 2006 Dec 14;355(24):2533-4117167136
Cites: Can J Gastroenterol. 2006 Nov;20(11):699-71017111052
In order to investigate the practice for control of patients with colorectal adenomata and cancer, a questionnaire investigation was carried out in 1990-1991 among 53 Danish surgical departments. The investigation revealed great differences in the control programmes offered to these patients as regards the methods, the intensity and duration. In addition, differences were present in the control pattern for adenomata in specialist departments as compared with the remaining departments where there was a tendency to very frequent but, on the other hand, brief control. On the basis of these results, it is considered necessary that a reference programme should be prepared on this subject.
Colonoscopy provides incomplete protection from colorectal cancer (CRC), but determinants of post-colonoscopy CRC are not well understood. We compared clinical features and molecular characteristics of CRCs diagnosed at different time intervals after a previous colonoscopy.
We performed a population-based, cross-sectional study of incident CRC cases in Denmark (2007-2011), categorized as post-colonoscopy or detected during diagnostic colonoscopy (in patients with no prior colonoscopy). We compared prevalence of proximal location and DNA mismatch repair deficiency (dMMR) in CRC tumors, relative to time since previous colonoscopy, using logistic regression and cubic splines to assess temporal variation.
Of 10,365 incident CRCs, 725 occurred after colonoscopy examinations (7.0%). These were more often located in the proximal colon (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.90-2.89) and were more likely to have dMMR (OR, 1.26; 95% CI, 1.00-1.59), but were less likely to be metastatic at presentation (OR, 0.65; 95% CI, 0.48-0.89) compared with CRCs diagnosed in patients with no prior colonoscopy. The highest proportions of proximal and/or dMMR tumors were observed in CRCs diagnosed 3-6 years after colonoscopy, but these features were still more frequent among cancers diagnosed up to 10 years after colonoscopy. The relative excess of dMMR tumors was most pronounced in distal cancers. In an analysis of 85 cases detected after colonoscopy, we found BRAF mutations in 23% of tumors and that 7% of cases had features of Lynch syndrome. Colonoscopy exams were incomplete in a higher proportion of cases diagnosed within
Cites: Am J Gastroenterol. 2012 Sep;107(9):1315-29; quiz 1314, 133022710576
Cites: Am J Clin Pathol. 2014 Apr;141(4):559-7224619758
First-degree relatives (n = 206) of patients operated on for colorectal cancer (CRC) (n = 181) were offered a colonoscopic screening examination; 169 relatives (82%) attended. The findings were compared with those in a normal population sample with no CRC in first-degree relatives (n = 308), aged 50-59 years, who had been screened by means of flexible sigmoidoscopy. Three carcinomas and 176 polyps were found in 56 of 95 male relatives (57%) and 34 of 74 female relatives (46%). The adenoma prevalence rate was 37 (39%) and 26 (35%) for male and female relatives, respectively. In the 50- to 59-year age group, the adenoma prevalence rates for both sexes collectively and for women separately were significantly higher among relatives than among the population without CRC relatives. Hyperplastic polyps were larger, whereas adenomas were similar in size among relatives compared with the normal population. Colonoscopy may be a suitable method of choice for screening first-degree relatives of patients with CRC.
There is clear evidence of reduced morbidity and mortality from regular colonoscopy programs in patients with Lynch syndrome (LS). Today, also individuals with empirically increased risks of colorectal cancer (CRC) are offered colonoscopic surveillance. The aim was to compare the findings at the first screening colonoscopy in LS carriers, and individuals with an increased risk of bowel cancer due to family history of CRC with a control population.
Altogether 1397 individuals with an increased risk for CRC were divided in four risk groups: one with LS carriers and three groups with individuals with different family history of CRC. The findings were compared between the different risk groups and a control group consisting of 745 individuals from a control population who took part in a population-based colonoscopy study.
In LS, 30% of the individuals had adenomas and 10% advanced adenomas. The corresponding figures in the other risk groups were 14-24% and 4-7%, compared with 10% and 3% in the control group. The relative risk of having adenomas and advanced adenomas was, compared to controls, significantly higher for all risk groups except the group with the lowest risk. Age was a strong predictor for adenomas and advanced adenomas in both risk individuals and controls.
Individuals with a family history of CRC have a high prevalence and cumulative risk of adenomas and advanced adenomas, and screening is motivated also in this risk group.