Population screening for colorectal cancer: advantages and drawbacks

Screening for colorectal cancer (CRC) has been shown to reduce mortality from the disease as well as incidence. Several methods for screening are available, but none are ideal. The present short review discusses the advantages and drawbacks using fecal occult blood tests (FOBTs), fecal DNA tests, flexible sigmoidoscopy (FS), colonoscopy, double contrast barium enema, and computed tomographic colonoscopy. The use of FOBTs with following colonoscopy in persons with a positive test has been shown to reduce mortality as well as the incidence of CRC in several randomized trials. It is likely that other methods will do the same, but it is not clear how large the benefit will be. Repeated testing is necessary for FOBTs and DNA tests as well as FS, and a high degree of acceptability is crucial for the effectivity of all tests in a national program. National services may be subject to variations in enthusiasm and expertise, resulting in varying acceptability and number of complications. It is recommended to perform pilot studies in limited populations (as in the UK) before embarking on a screening program on a national level.     

Influence of long-term colonoscopic surveillance on incidence of colorectal cancer and death from the disease in patients with precursors (adenomas)

Case-control studies and short term prospective studies have suggested that selected groups of patients with precursors of colorectal cancer may benefit from colonoscopic surveillance after initial removal of adenomas. The aim of the present study was to demonstrate such a possible benefit from long term (1-24 years) colonoscopic surveillance in a population of patients with all types of adenomas regardless of size and way of removal. Two thousand and forty-one patients with a first time diagnosis of colorectal adenoma were included in prospective surveillance between year 1978 and 2002. All adenomas were considered. Incidence of CRC and mortality from CRC was calculated, using age, sex, and calendar specific number of person years of follow-up for comparison with the standard Danish population. CRC was found in 27 patients, the expected number being 41 (RR 0.65, 95% CI 0.43-0.95). Three of the 27 patients died from CRC, the expected number being 25 (RR 0.12, 95% CI 0.03-0.36). A total of 6 289 colonoscopies resulted in severe complications in 20 patients and two died from complications. Long-term colonoscopic surveillance may reduce incidence of CRC as well as mortality in patients with sporadic adenomas. The benefit is reduced to a minor degree by complications from surveillance     

Comparison of the three-level and the five-level versions of the EQ-5D

The European Journal of Health Economics - EQ-5D is a generic instrument to measure health-related quality of life. In 2009, a new version, EQ-5D-5L, was introduced as an attempt to reduce ceiling...     

Faecal calprotectin levels in a high risk population for colorectal neoplasia

BACKGROUND: Faecal concentrations of the protein calprotectin have been found to be elevated in patients with colorectal neoplasia, suggesting that it might be used as a screening tool for colorectal cancer as well as adenomas. AIMS: To measure the sensitivity and specificity of faecal calprotectin for the detection of adenomas in high risk individuals undergoing colonoscopy. Also, to investigate between and within stool variability of calprotectin concentrations. SUBJECTS: A total of 814 patients planned for colonoscopy were included for the following indications: positive faecal occult blood test, 25; neoplasia surveillance, 605; newly detected polyp, 130; and family risk, 54. METHODS: Two faecal samples from each of two stools were analysed using the PhiCal ELISA test device (Nycomed Pharma AS). RESULTS: Adenoma patients had significantly higher calprotectin levels than normal subjects (median 9.1 (95% confidence interval 7.5-10.1) v 6.6 (5.6-7.4)mg/l). There was no significant decrease in calprotectin levels after polypectomy. Levels in cancer patients were significantly higher than those in all other subgroups (median 17.6 mg/l (11.5-31.0)). With a cut off limit of 10 mg/l, the sensitivity for cancer was 74% and for adenoma 43%. Corresponding specificity values were 64% for no cancer and 67% for no neoplasia (cancer+adenoma). Specificity varied from 71% for one stool sample to 63% for four samples. Stool variability was small, suggesting that two spots from one stool were as discriminative as two spots from each of two stools. CONCLUSIONS: The sensitivity and specificity of faecal calprotectin levels as a marker for colorectal adenoma and carcinoma justifies its use in high risk groups, but specificity is too low for screening of average risk persons. Lack of a decrease in levels after polypectomy may be due to a more widespread leucocyte migration into the intestinal lumen than that at the polyp site, and needs further investigation.     

A randomised study of screening for colorectal cancer using faecal occult blood testing: results after 13 years and seven biennial screening rounds.

BACKGROUND: Three randomised trials have demonstrated reduction in mortality from colorectal cancer (CRC) by repeated screening with faecal occult blood tests, including the trial presented here, which is the only one still in progress. AIMS: To evaluate reduction in mortality after seven screening rounds and the possible influence of compliance on mortality from CRC. METHODS: At Funen in Denmark, random allocation to biennial screening with Hemoccult-II in 30 967 subjects aged 45-75 years and 30,966 controls was performed in 1985 from a population of 137,485 of the same age. Only participants who completed the first screening round were invited for further screening. Colonoscopy was offered if the test was positive. The primary end point was death from CRC, and the 10 year results were published in 1996. RESULTS: From the beginning of the first screening to the seventh round, mean age increased from 59.8 to 70.0 years in the screening and control groups, and the male/female ratio decreased from 0.92 to 0.81. Those who accepted screening were younger than non-responders. Positivity rates varied from 0.8% to 3.8%, the cumulative ratio of a positive test was 5.1% after seven rounds, and 4.8% of patients had at least one colonoscopy. Mortality from CRC was significantly less in the screening group (relative risk (RR) 0.82 (0.69-0.97)), and the reduction in mortality was most pronounced above the sigmoid colon. After seven rounds, RR was reduced to less than 0.70 compared with controls. Mortality rates from causes other than CRC did not differ. Non-responders had a significantly increased risk of death from CRC compared with those who accepted the full programme. Subjects who accepted the first screening, but not subsequent ones, demonstrated a tendency towards increased risk. CONCLUSIONS: The persistent reduction in mortality from CRC in a biennial screening program with Hemoccult-II, and a reduction in RR to less than 0.70 in those adhering to the programme, support attempts to introduce larger scale population screening programmes. The smaller effect on mortality from CRC in the rectum and sigmoid colon suggests evaluation by additional flexible sigmoidoscopy with longer intervals.     

Sleep-disordered breathing in stable methadone programme patients: a pilot study

Aims. To explore the possibility that stable MMP patients have sleep-disordered breathing (SDB) and abnormal sleep architecture defined by nocturnal sleep stages and sleep efficiency. Design. Observational. Setting. Regional Methadone Service and sleep disorders laboratory in a university affiliated hospital. Participants and measurements. Ten stable MMP patients and nine normal subjects were assessed clinically and with overnight polysomnography. Findings. There were no differences in age, sex and body mass index between the groups. The methadone dose ranged between 50 and 120 mg/day. Six patients had central apnoea index (CAI) greater than 5, four had a CAI greater than 10 and three of these exhibited periodic breathing. No normal subject had central sleep apnoea. The patients had lower sleep efficiency ( p < 0.05), less slow wave sleep ( p < 0.01), less rapid eye movement sleep ( p < 0.05) and more Stage 2 sleep ( p < 0.05) than controls. Conclusions. Stable MMP patients have more sleep architecture abnormalities than controls and a higher prevalence of central sleep apnoea. Further studies are needed to confirm these findings, to delineate the mechanisms for the abnormalities and to assess whether the SDB is related to sudden death in stable MMP patients. We recommend that MMP patients have awake and sleep respiration assessed to identify those potentially at risk.     

Prognostic evaluation of planned follow- up in patients with colorectal adenomas

Between 1978 and 1986 colorectal adenomas without invasion were removed in 552 patients under 76 years of age. Patients were randomly allocated to different follow-up groups with intervals of colorectal examination varying from 6 to 48 months after the initial polypectomy. A large bowel carcinoma developed in three patients and new adenomas in 87 patients. Based on the morphology of the initial adenomas possible relationships between prognostic factors and the risk of new adenoma formation were assessed using life-table analysis. The advantage of a possible decrease in the risk of developing carcinoma was offset by the disadvantage of eight severe complications occurring in 1818 colonoscopies, one of which proved fatal. The occurrence of one of the three carcinomas was considered a failure of the follow-up programme.