Implementing screening for colorectal cancer

The effect of test kit provision, and individual and family education on the uptake rates of fecal occult blood test in an Asian population: a randomized controlled trial

PURPOSE

The purpose of the study was to investigate whether fecal occult blood test (FOBT) home-delivery and individual education or combined with family education increases FOBT uptake rates in Singapore.

METHODS

This is a randomized controlled intervention study of Singaporean residents aged 50 years and above, conducted in May 2012 till May 2013. Eligible individuals in randomly selected households were screened, and one member was randomly selected and allocated to one of the four arms: Group A (individual and family education, FOBT kits provided), Group B (individual education only, FOBT kits provided), Group C (no education, FOBT kits provided) and Group D (no education or FOBT kits provided).

RESULTS

Overall response rate was 74.7 %. The FOBT return rates for groups A, B, C and D were 24.5 % [CI 16.2-34.4 %], 25.3 % [CI 16.4-36.0 %], 10.7 % [CI 4.7-19.9 %] and 2.2 % [CI 0.3-7.7 %], respectively. Respondents who were provided education and home-delivered FOBT kits were 15 times more likely to return FOBT kits [Group A: OR 15.0 (3.4-66.2); Group B: OR 15.5 (3.5-68.8)] and those provided with home-delivered FOBT without education were five times more likely to return FOBT kits [Group C: OR 5.8 (1.2-28.3)] than those without education and FOBT kits (Group D). There was no significant difference in return of FOBT kits whether education was provided to subject with or without a family member.

CONCLUSION

Home delivery of FOBT kits increased FOBT return rates and individual education combined with home-delivered FOBT increased FOBT return rates even further. However, additional combination with family education did not increase FOBT rates further.

Patient satisfaction with lower gastrointestinal endoscopy: doctors, nurse and nonmedical endoscopists

AIM

Assessment of patient satisfaction with lower gastrointestinal endoscopy (LGE) comprising colonoscopy and flexible sigmoidoscopy is gaining increasing importance. We have now trained non healthcare professionals such as nonmedical endoscopists (NMEs) to perform LGE to overcome shortage of trained endoscopists. The aim of this study was to prospectively determine patient satisfaction, factors affecting satisfaction with LGE and to compare with nurses, NME and medical endoscopists, in terms of patient satisfaction.

METHOD

Consecutive patients undergoing LGE answered specially developed patient satisfaction questionnaire at discharge and 24 h thereafter. This questionnaire was a modification of m-Group Health Association of America questionnaire. Construct and face validity of questionnaire were tested by an expert group. Demographic and clinical data was prospectively collected. Multivariate regression analysis was performed to determine factors influencing patient satisfaction.

RESULTS

Some 503 patients were surveyed after LGE. Examinations were performed by nurse (n = 105), doctor (n = 191), or NMEs (n = 155). There were no differences between three groups in terms of completion rates/complications. No differences were detected between endoscopists in patient rating for overall satisfaction (P = 0.6), technical skills (P = 0.58), communication skills (P = 0.61) or interpersonal skills (0.59). Multivariate regression analysis showed that higher preprocedure anxiety, history of pelvic operations/hysterectomy and higher pain scores were associated with adverse patient satisfaction and preprocedure anxiety, history of hysterectomy and female gender were associated with higher pain scores.

CONCLUSION

This study has shown that there are no differences in patient satisfaction with LGE performed by nurse, doctor or NME. The most important factor affecting patient satisfaction is degree of discomfort/pain experienced by patient.

The potential for prevention of colorectal cancer in the UK

On the basis of recent trends (up to 2004), future projections of the incidence of colorectal cancer in the UK in the next 24 years are for a continuing decline in rates (age-standardized rates predicted to be about 9% lower). The potential for modification of the predicted burden through the implementation of five preventive interventions, for which national policies or targets have been promulgated, is examined. We estimate that 31.5% of cancers in men and 18.4% in women could be prevented if reasonable targets with respect to diet (reduced consumption of red meat, increased fruit and vegetables), exercise (30 min 5 days a week), alcohol consumption (3 U a day for men, 2 U for women) and weight control were achieved. This estimate assumes a return of the weight profile of the UK population to that present 20 years ago; if the aim were simply to halt the increasing trend in overweight, the preventable fractions would be 28% in men and 14.7% in women. These predictions suggest that realistic lifestyle modifications can result in a substantial reduction in cases of this major cancer. The benefit in terms of avoided deaths is probably greater than that which can be achieved through implementation of the national screening programme, and improvements in treatment.

Virtual colonoscopy vs conventional colonoscopy in patients at high risk of colorectal cancer--a prospective trial of 150 patients

OBJECTIVE

Virtual colonoscopy (VC)/CT colonography has advantages over the well-documented limitations of colonoscopy/barium enema. This prospective blinded investigative comparison trial aimed to evaluate the ability of VC to assess the large bowel, compared to conventional colonoscopy (CC), in patients at high risk of colorectal cancer (CRC).

METHOD

We studied 150 patients (73 males, mean age 60.9 years) at high risk of CRC. Following bowel preparation, VC was undertaken using colonic insufflation and 2D-spiral CT acquisition. Two radiologists reported the images and a consensual agreement reached. Direct comparison was made with CC (performed later the same day). Interobserver agreement was calculated using the Kappa method. Postal questionnaires sought patient preference.

RESULTS

Virtual colonoscopy visualized the caecum in all cases. Five (3.33%) VCs were classified as inadequate owing to poor distension/faecal residue. CC completion rate was 86%. Ultimately, 44 patients had normal findings, 44 had diverticular disease, 11 had inflammatory bowel disease, 18 had cancers, and 33 patients had 42 polyps. VC identified 19 cancers--a sensitivity and specificity of 100% and 99.2% respectively. For detecting polyps > 10 mm, VC had a sensitivity and specificity (per patient) of 91% and 99.2% respectively. VC identified four polyps proximal to stenosing carcinomas and extracolonic malignancies in nine patients (6%). No procedural complications occurred with either investigation. A Kappa score achieved for interobserver agreement was 0.777.

CONCLUSION

Virtual colonoscopy is an effective and safe method for evaluating the bowel and was the investigation of choice amongst patients surveyed. VC provided information additional to CC on both proximal and extracolonic pathology. VC may become the diagnostic procedure of choice for symptomatic patients at high risk of CRC, with CC being reserved for therapeutic intervention, or where a tissue diagnosis is required.

Predicting the impact of the screening programme for colorectal cancer in the UK

Objectives

Screening for colorectal cancer by biennial testing for faecal occult blood is being introduced in the UK from 2007. We examine the likely impact of the programme, in terms of reduced mortality, lives saved and changes in incidence, over the next 20 years.

Setting

Projections of incidence and mortality of colorectal cancer in England, and the policy that has been adopted for screening in England (biennial at ages 60–69 from 2007, then 60–74 in 2010).

Methods

The results are based on the output of a simulation model that has been used to examine cost-effectiveness of screening policy options, with two scenarios regarding compliance with screening; both assume that 20% of the population will never attend for screening, but attendance of those who do is modelled either as a random 60% or 80%, at each screening round.

Results

The decrease in mortality rates expected 20 years after introducing screening is 13–17% in men and 12–15% in women (depending on the attendance levels). The model predicts an initial rise in incidence, followed (after six to seven years) by a fall, so that there is little net change in the number of cases detected over a 20-year period.

Conclusion

Percentage changes in mortality seem modest, but the projected saving in terms of numbers of lives is not negligible – 1800–2400 per year by 2025 in England (equivalent numbers are 2200–2700 in all over the UK). Newer screening modalities may improve on these projected results.

In vivo confocal laser scanning chromo-endomicroscopy of colorectal neoplasia: changing the technological paradigm

Recently, miniaturization of a novel confocal laser endomicroscope (Optiscan Pty, Notting Hill, Victoria, Australia) has permitted functional integration into the distal tip of a conventional video colonoscope (Pentax EC3870K; Pentax, Tokyo, Japan) enabling imaging of the surface epithelium and the underlying lamina propria during ongoing video endoscopy. Using endomicroscopy and intravenous sodium fluorescein as a contrast agent, 'virtual histology' can be created, which allows visualization of both the surface epithelium, and some of the lamina propria (down to a quarter of a millimetre), including the microvasculature. Confocal endomicroscopy may have major implications in the future of colonoscopy as uniquely it allows in vivo diagnosis of colonic intraepithelial neoplasia and carcinoma enabling 'smart' biopsy targeting and hence potentially influencing 'on table' management decisions. Initial pilot data have now shown that confocal imaging in vivo using the newly developed EC3870K has high overall accuracy for the immediate diagnosis of intraepithelial neoplasia and carcinoma in sporadic screened cohorts, but also has a role in the detection of intraepithelial neoplasia detection in chronic ulcerative colitis cancer screening when used in conjunction with methylene blue chromoscopy. We discuss the current evidence in support of confocal endomicroscopy in the colorectum and explore the new diagnostic possibilities for this technology.

Novel clinical in vivo roles for indigo carmine: high-magnification chromoscopic colonoscopy

Since the adenoma-carcinoma sequence was first proposed by Morson in the 1970s, it has become widely accepted that detection and subsequent removal of polypoid adenomas from the colon reduces the incidence of colorectal cancer. These adenomas are relatively easy to detect by conventional colonoscopy; however, large population studies have shown that despite resection of polypoid adenomas, interval colorectal cancers still occurred. Recent advances in technology have given today's endoscopists access to high-resolution and high-magnification scopes, which has facilitated detection of flat and depressed colorectal lesions. Current data suggest that such morphologically distinct lesions may account for up to 30% of all colorectal adenomas. Furthermore, flat and depressed lesions of the large bowel may confer greater malignant potential compared to polypoid adenomas. The majority of flat lesions show only subtle changes by conventional colonoscopy, but the use of stains, such as indigocarmine, in addition to magnification colonoscopy can enhance their detection significantly. In this paper, we discuss the rationale for detecting flat colorectal lesions. We explore the use of high-magnification colonoscopy and chromoendoscopy, with particular reference to the application of indigocarmine, in this patient group. We also discuss the novel therapeutic techniques now available for these lesions.

Novel colorectal endoscopic in vivo imaging and resection practice: a short practice guide for interventional endoscopists

Colorectal cancer remains a leading cause of cancer death in the UK. With the advent of screening programmes and developing techniques designed to treat and stage colorectal neoplasia, there is increasing pressure on the colonoscopist to keep up to date with the latest practices in this area. This review looks at the basic principles behind endoscopic mucosal resection and forward to the potential endoscopic tools, including high-magnification chromoscopic colonoscopy, high-frequency miniprobe ultrasound and confocal laser scanning endomicroscopic colonoscopy, that may soon become part of routine colorectal cancer management.

Recent advances in chromoscopic colonoscopy and endomicroscopy

The basic rationale for secondary prevention of colorectal carcinoma is by endoscopic polypectomy. New technologies in the form of high-magnification or "zoom" colonoscopy complemented by chromoscopic agents permit early detection of neoplastic colorectal lesions, particularly flat and depressed types. Detailed morphologic characteristics of the surface crypt or "pit pattern" can be obtained with these techniques, enabling an in vivo "optical biopsy" and staging tool. Establishing suitability for endoscopic resection or surgical excision can be enhanced using these techniques. Furthermore, chromoscopic colonoscopy may have a role in routine endoscopic colorectal cancer surveillance programs in patients at high risk for colorectal neoplasia, such as those with long-standing ulcerative colitis and familial colorectal cancer syndromes. This review summarizes recent data regarding the prevalence and histopathologic characteristics of flat and depressed colorectal lesions in Western cohorts and describes how their detection and management can be improved by chromoscopy and magnification technology. We outline these techniques from a clinical perspective and describe the basic principles of endoscopic mucosal resection.

Is the type of test used for mass colorectal cancer screening a determinant of compliance? A cluster-randomized controlled trial comparing fecal occult blood testing with flexible sigmoidoscopy

BACKGROUND

The efficacy of colorectal cancer screening has been proved, and three different screening tests are recommended by international guidelines: the faecal occult blood test, flexible sigmoidoscopy and colonoscopy. While the effectiveness of a screening program depends on the compliance obtained, the role of the type of test on compliance has not yet been sufficiently studied.

AIMS

To measure the effect of the type of screening test used, i.e. faecal occult blood test or flexible sigmoidoscopy, on the compliance to colorectal cancer screening programs.

SUBJECTS AND METHODS

A cluster-randomized two-arm trial was conducted. We randomly assigned 20 GP's practices that had an average of 150 patients between 50 and 74 years old.

RESULTS

1449 individuals were referred to faecal occult blood test and 1538 to flexible sigmoidoscopy. The faecal occult blood test obtained higher compliance: 17.2% (95%CI 12.5-25.7) versus 7.0% (95%CI 5.7-9.0). The socio-economic status was an effect modifier of the test type: the effect of the type of test was smaller in low socioeconomic classes.

CONCLUSIONS

The type of screening test used for colorectal cancer is a determinant of participation. In a low compliance area, better compliance will result from offering the faecal occult blood test than from the flexible sigmoidoscopy.

Rectal aberrant crypt foci identified using high-magnification-chromoscopic colonoscopy: biomarkers for flat and depressed neoplasia

BACKGROUND

Aberrant crypt foci may represent preneoplastic lesions in the human colon. The prevalence of aberrant crypt foci detected using magnification chromoscopic colonoscopy is known to follow a stepwise progression from normal subjects to those with exophytic adenomas and colon cancer. No studies have addressed the prevalence of rectal aberrant crypt foci in patients with flat and depressed colonic lesions that cluster within the right hemi-colon and may undergo de novo neoplastic transformation.

METHODS

All patients underwent total colonoscopy by a single endoscopist using the Olympus CF240Z magnifying colonoscope. Flat and depressed lesions were diagnosed using targeted indigo carmine chromoscopy. Prior to extubation, pan high-magnification-chromoscopy using indigo carmine was applied to the rectum and the distal 10 cm of mucosa examined using forward and retroflexed views. Aberrant crypt foci were defined as two or more crypts with dilated or slit-like openings that were raised above the adjacent mucosa. Using high-magnification chromoscopic colonoscopy we assessed the prevalence and dysplastic features of aberrant crypt foci in three groups: endoscopically "normal" subjects, patients with flat/depressed adenoma, and flat/depressed cancer.

RESULTS

Two thousand five hundred and fifty-nine patients underwent colonoscopy of which 1,000 were eligible for inclusion. The median number of aberrant crypt foci per patient in the endoscopically normal, adenoma, and cancer group was 1 (range: 0-5), 9 (range: 0-22), and 38 (range: 14-64), respectively. The estimated relative risk of dysplastic aberrant crypt foci when comparing the flat adenoma group with the endoscopically "normal" group was 4.68 (95% CI: 2.23-9.91) with the relative risk for flat cancer versus endoscopically normal group being 21.8 (95% CI: 10.9-23.8). Patients with >5 flat adenomas had higher crypt foci densities than those with <5 adenomas (r=0.53; p<0.001).

CONCLUSIONS

The number of aberrant crypt foci in normal patients, patients with flat adenoma, and flat cancer follow a stepwise incremental change as previously observed for exophytic adenomas and cancer. Detection of aberrant crypt foci in the rectum may be a useful biomarker for proximal colonic flat neoplasia and could be used at index flexible sigmoidoscopic screening to stratify risk of proximal colonic neoplasia. Patients with dysplastic aberrant crypt foci of high density should receive total colonoscopy.

Selecting patients for flexible sigmoidoscopy. Determinants of incomplete depth of insertion

BACKGROUND

Flexible sigmoidoscopy (FS) is an effective method to prevent and reduce mortality from colorectal carcinoma (CRC). Incomplete depth of insertion (IDI) during FS may result in missed polyps and carcinomas. To determine whether it is possible to predict IDI, the authors analyzed factors that affected the depth of insertion in FS.

METHODS

For the current study, FS results were recorded prospectively over a 5-year period. A questionnaire was administered to the patient by the investigator prior to FS to collect data, including age, gender, weight, comorbid illnesses, history of prior abdominal and pelvic surgeries, family history of colon carcinoma or polyps, and prior FS or colonoscopies. The depth of insertion of the flexible sigmoidoscope from the anal verge, which was defined as the reading on the outside of the instrument at its maximal insertion, was measured in centimeters. IDI was defined as a depth of insertion < 50 cm. Classification and regression tree analysis was used to develop a model that included variables predictive of IDI.

RESULTS

The best classification tree included gender, age < 69 years (in women), and a history of hysterectomy. Men had a < 5% risk of an IDI and women age < 69 years without a hysterectomy fared as well (6.6%). Older women and younger women who underwent hysterectomy had higher rates of IDI (29.2% and 22.3%, respectively.)

CONCLUSIONS

The authors developed a model based on age, gender, and hysterectomy status that, after further validation, may be useful for predicting which patients likely will have an incomplete examination. In those patients who have a high probability of IDI, the choice can be made to offer colonoscopy or perform FS under sedation, with analgesia, or with the help of distraction techniques.

Using iron deficiency tests for colorectal cancer screening: a feasibility study in one UK general practice

Iron deficiency is common at presentation in colorectal cancer. Testing for it may complement other screening tests such as faecal occult blood testing and sigmoidoscopy. We therefore examined the feasibility of offering iron deficiency testing to patients in a primary care setting in the UK, offering testing to all 1240 patients aged 55-74 years in one general practice in South Wales, UK. Patients with abnormal results were assessed and offered further investigations. Five hundred and fifty-one people (44.4%) attended for iron deficiency blood tests, of whom 26 patients (4.7%) were iron deficient and offered endoscopic assessment. This identified two cases of benign neoplasia amenable to treatment and no cases of cancer. Iron deficiency testing in a screening context appeared feasible although uptake may be low.

Public awareness of risk factors and screening for colorectal cancer in Europe

Colorectal cancer (CRC) is the commonest site for malignancy in Europe. The Commissioner for Health wishes to promote screening for colorectal, breast and cervical cancer in Europe. The aim of this study was to assess public knowledge of CRC in Europe and likely take up of free screening. To this end 20710 members of the public from 21 European countries were interviewed by means of a regular survey amongst consumers (Omnibus survey) using 13 stem questions. Forty-eight per cent thought the population were at equal risk of CRC, only 57% were aware of age and 54% of family history as risk factors. Although 70% were aware of dietary factors, only 30% knew that lack of exercise might be a risk factor. Only 51% had knowledge of CRC screening but 75% were 'very', or 'quite interested, in taking up faecal occult blood (FOB) screening if offered free. Barriers to screening were lack of awareness of risk (31%), youth (22%) and an un-anaesthetic test (19%). There was a big cultural difference in willingness of the public to discuss bowel symptoms: there was a major barrier in Finland (91%), Britain (84%), Luxembourg (82%), Poland (81%) and Portugal (80%); less of a barrier in Spain (49%), Italy (44%) and Iceland (39%). In conclusion, the challenge of achieving high compliance for CRC screening must be a major objective amongst EU member states and non-aligned countries of Europe in the next decade, because it is known that the non-compliant group are those at greatest risk of death from CRC. This study has shown that awareness of CRC is low in Europe and that an educational programme will be essential to achieve high compliance for CRC screening as a means of reducing deaths from bowel cancer.

Ethical issues for cancer screenings. Five countries--four types of cancer

In recent years, medical ethics has become an undisputed part of medical studies. Many people believe that modern advances in medical technology--such as the development of dialysis machines, respirators, magnetic resonance imaging, and genetic testing and types of cancer screenings--have created the bioethical dilemmas that confront physicians in the 21st century. Debates over research and screening ethics have until recently revolved around two related questions: the voluntary, informed consent of subjects, and the appropriate relationship between risk and benefit to subjects in the experiment. Every patient has a right to full and accurate information about his or her medical condition. This legal principle arose primarily through court decisions concerning informed consent, but over time, physicians recognized that most patients prefer to learn the truth about their condition and use the information well. To screen is to search for disease in the absence of symptoms or, in other words, to attempt to find disease in someone not thought to have a disease. Examples of screening include routine mammography to detect breast cancer, routine Pap smears to detect cervical cancer and routine prostate specific antigen (PSA) testing to detect prostate cancer. Ethical principles to be followed in cancer screening programs are intended mainly to minimize unnecessary harm to the participating individuals. Numerous ethical questions can be raised about the practice of screening for disease. This paper reviews recommendation for cancer screening from five countries, examine them from an ethical perspective, and make conclusion from this analysis.

Observer Variation in the Detection of Colorectal Neoplasia on Double-contrast Barium Enema: Implications for Colorectal Cancer Screening and Training

AIM

To assess inter-observer error for the diagnosis of neoplasia on double contrast barium enema (DCBE) in the light of claims that no additional interpretative training would be needed for implementation in a national screening programme.

MATERIALS AND METHODS

10 experts, 10 consultants, and 10 experienced trainees each reported 20 DCBE studies, of which two showed cancer, three showed large polyps, four showed small polyps, and 12 were normal. Inter-observer variation was compared using odds ratios with the trainee group as reference (baseline group).

RESULTS

Experts were significantly more likely to correctly identify neoplasia on DCBE than trainees. The odds of a correct diagnosis for experts were 2.79 (95% CI 2.04, 3.81) for cancer, 2.36 (1.88, 2.97) for large polyps, and 3.50 (1.98, 6.18) for small polyps. While consultants were more likely to correctly diagnose a large polyp than trainees, 1.45 (1.15, 1.84), there was no significant difference between these two groups for the correct diagnosis of either cancer, 1.24 (0.52, 2.96), or small polyps, 1.26 (0.83, 1.90). A cancer was missed by 6 (60%) experts, 9 (90%) consultants, and 8 (80%) trainees. Large polyps were missed by 4 (40%) experts, 5 (50%) consultants, and 6 (60%) trainees. There was no significant difference between any group when false positive diagnoses were considered.

CONCLUSIONS

There is considerable inter-observer perceptive error for the diagnosis of neoplasia on DCBE. Experts performed significantly better than other observers but the overall standard of performance was poor, even amongst experts.

Multi-detector row CT colonography: effect of collimation, pitch, and orientation on polyp detection in a human colectomy specimen

PURPOSE

To investigate the effects of orientation, collimation, pitch, and tube current setting on polyp detection at multi-detector row computed tomographic (CT) colonography and to determine the optimal combination of scanning parameters for screening.

MATERIALS AND METHODS

A colectomy specimen containing 117 polyps of different sizes was insufflated and imaged with a multi-detector row CT scanner at various collimation (1.25 and 2.5 mm), pitch (3 and 6), and tube current (50, 100, and 150 mA) settings. Two-dimensional multiplanar reformatted images and three-dimensional endoluminal surface renderings from the 12 resultant data sets were examined by one observer for the presence and conspicuity of polyps. The results were analyzed with Poisson regression and logistic regression to determine the effects of scanning parameters and of specimen orientation on polyp detection.

RESULTS

The percentage of polyps that were detected significantly increased when collimation (P =.008) and table feed (P =.03) were decreased. Increased tube current resulted in improved detection only of polyps with a diameter of less than 5 mm. Polyps of less than 5 mm were optimally depicted with a collimation of 1.25 mm, a pitch of 3, and a tube current setting of 150 mA; polyps with a diameter greater than 5 mm were adequately depicted with 1.25-mm collimation and with either pitch setting and any of the three tube current settings. Small polyps in the transverse segment (positioned at a 90 degrees angle to the z axis of scanning) were significantly less visible than those in parallel or oblique orientations (P <.001). The effective radiation dose, calculated with a Monte Carlo simulation, was 1.4-10.0 mSv.

CONCLUSION

Detection of small polyps (<5 mm) with multi-detector row CT is highly dependent on collimation, pitch, and, to a lesser extent, tube current. Collimation of 1.25 mm, combined with pitch of 6 and tube current of 50 mA, provides for reliable detection of polyps 5 mm or larger while limiting the effective radiation dose. Polyps smaller than 5 mm, however, may be poorly depicted with use of these settings in the transverse colon.

Problems in screening colorectal cancer in the elderly

AIM: To explore the problems in the screening of colorectal carcinoma in the elderly.

METHODS: Three models of colorectal cancer prevention were examined: standard screening, active check-up of suspected cases and summons to have endoscopic check-up for previously diagnosed colorectal polyps. The study was performed among three groups of elderly individuals: Group 1 (167 cases), hospitalized asymptomatic individuals without symptoms in large intestines. Group 2 (612 cases): old individuals at home for the aged, out of which 32 showed symptoms of colon disorders; Group 3 (44 cases): elderly people with diagnosed polyps. As a result of 1788 rectosigmoidoscopies, we identified 61 individuals with polyps, out of which 44 patients were over 65 years old. However, only 9 of these 44 individuals agreed to have the endoscopy performed again.

RESULTS: One cancer and 13 polyps were detected in Group 1, and two polyps in Group 2. However, it should be noted that only eleven individuals from Group 2 agreed to have the endoscopy. In Group 3, there were no relapses of the polyps among the nine individuals who came back for the endoscopy.

CONCLUSION: Poor understanding of the screening procedures is one of the greatest problems in early detection of the cancer in the aged. Paradoxically, the cooperation is better with hospitalized patients, than with “successfully old” persons.

Colonoscopy or barium enema for population colorectal cancer screening?

There is good evidence from faecal occult blood testing trials that detection and removal of non-advanced colorectal neoplasms can achieve a reduction in colorectal cancer mortality. Both colonoscopy and barium enema have potential advantages and disadvantages if implemented for population screening. The relative merits of each are discussed.

Feasibility study of colonoscopy as the primary screening investigation in relatives of patients with colorectal cancer

AIM

Relatives of patients with colorectal cancer are thought to be at a higher risk for this disease than the average population. We aimed to determine whether colonoscopy is a feasible primary screening investigation for this group to identify premalignant and malignant lesions.

METHODS

A total of 449 people underwent colonoscopy and all had one or more relatives with colorectal cancer, of these, 212 were classified as 'asymptomatic' and 237 as being 'symptomatic'. Colonoscopy commenced at 40 years of age or 10 years younger than the youngest affected relative.

RESULTS

Neoplastic change, benign and malignant, was found in 25.5% of the 'asymptomatic' group and 24% of the 'symptomatic' group; in 26% of those with one first degree relative, 39% with two or more first degree relatives and only 19% with second degree relatives. 38% of lesions were out of reach of a flexible sigmoidoscope. No known complications occurred.

CONCLUSIONS

It is feasible to perform colonoscopy as the primary investigation for the first degree relatives of patients with colorectal cancer. The yield of neoplastic lesions is sufficient to make this appropriate.

Immediate CT pneumocolon for failed colonoscopy; comparison with routine pneumocolon

AIM

To assess the role and reliability of 2D CT pneumocolon in the diagnosis of colonic malignancy, and compare feasibility of referral sources.

MATERIALS AND METHODS

A prospective study of 50 patients with suspected large bowel malignancy. Patients underwent bowel cleansing, rectal air insufflation and contrast enhanced CT with 5 mm collimation, 3 mm reconstruction and a pitch of 1.4. Subsequent correlation was with pathology (16), colonoscopy (13), barium enema (5), ERCP (1) and clinical follow-up alone (8).

RESULTS

Diagnostic images were obtained in 43/50 patients (86% feasibility). Follow-up was obtained in 35/43 patients (one patient died of an unrelated cause, and seven patients were deemed unfit for further investigation). Seventeen colonic carcinomas were diagnosed (three false-positives: one ischaemic colitis, one diverticular stricture and one faecal mass), one diverticular stricture, one fistula, one pancreatic carcinoma and one ovarian malignancy. The remaining 14 were negative. Overall sensitivity was 100% (for lesions >1.5 cm) with a specificity of 94% for structural abnormalities, but only 82% for the correct identification of malignancy.

CONCLUSION

Computed tomography (CT) pneumocolon is a reliable alternative to barium enema where colonoscopy is incomplete, with the advantage of extraluminal screening, and examination of the proximal bowel. In the frail elderly or young unfit patient, it is a valuable additional diagnostic tool.

CT and bowel disease

CT has now come of age in the detection and demonstration of bowel pathology and is likely to supplant traditional imaging techniques further in the future. Its role here has been greatly aided by the advent of fast spiral CT sequences and, with the development of even faster multidetector CT systems, this can only increase.