Colorectal Cancer Screening Techniques Research Articles

Association between Rectal Optical Signatures and Colonic Neoplasia: Potential Applications for Screening

Field carcinogenesis detection represents a promising means for colorectal cancer (CRC) screening, although current techniques (e.g., flexible sigmoidoscopy) lack the requisite sensitivity. The novel optical technology low-coherence enhanced backscattering (LEBS) spectroscopy, allows identification of microscale architectural consequences of the field carcinogenesis in preclinical CRC models with unprecedented accuracy. To investigate the potential clinical translatability of this approach, we obtained biopsies from the normal-appearing rectal mucosa from patients undergoing colonoscopy (n = 219). LEBS signals were recorded through a bench-top instrument. Four parameters characterizing LEBS signal were linearly combined into a single marker. We found that LEBS signal parameters generally mirrored neoplasia progression from patients with no neoplasia, to 5 to 9 mm adenoma and to advanced adenomas. The composite LEBS marker calculated from the LEBS signal paralleled this risk status (ANOVA P < 0.001). Moreover, this was independent of CRC risk factors, benign colonic findings, or clinically unimportant lesions (diminutive adenomas, hyperplastic polyps). For advanced adenomas, the LEBS marker had a sensitivity of 100%, specificity of 80%, and area under the receiver operator characteristic curve of 0.895. Leave-one-out cross-validation and an independent data set (n = 51) supported the robustness of these findings. In conclusion, we provide the first demonstration that LEBS-detectable alterations in the endoscopically normal rectum were associated with the presence of neoplasia located elsewhere in the colon. This study provides the proof of concept that rectal LEBS analysis may potentially provide a minimally intrusive CRC screening technique. Further studies with an endoscopically compatible fiber optic probe are under way for multicenter clinical validation.

Colorectal Carcinoma Screening in Lagos, Nigeria, Are We Doing it Right?

BackgroundScreening for colorectal cancer (CRC) has proven effective in reducing disease mortality and is also cost effective. Recent reports indicate that colorectal cancer is not uncommon and presents with advanced disease in Nigeria. Thus this study was aimed at reviewing the practice of CRC screening among medical practitioners in Nigeria.MethodsA self-administered questionnaire was utilized to obtain data for this study, which was distributed to over 500 practising doctors in Lagos, Nigeria from September to November 2007. The data obtained from the questionnaire include basic demographics, type of practice, duration in years of medical practice described as short (≤ 5 years), medium (5 to 10 years) or long (> 10 years), and knowledge regarding CRC, as well as CRC screening techniques and methodologies.ResultsThere were 300 respondents with a mean age (SD) of 33 (7.8) years and an age range of 23 - 67 years. In terms of duration of medical practice, 190 (63%) were short, 43 (14%) medium and 67 (23%) long. Majority (65%) of the respondents were in teaching hospitals, 18.5% in private hospitals and 5.7% were in general (community) hospitals. The knowledge of the clinical features as well as the risk factors of CRC was fair in over 75% of the respondents. Most respondents, 265 (87.8%), agreed that CRC was worth screening for; 21 (5%) did not. In all, 246 (82%) gave reasons for their responses. However, just over half of the respondents employed one of the following: faecal occult blood test (FOBT), double contrast barium enema (DCBE), flexible sigmoidoscopy, colonoscopy, or a combination of any of the techniques for screening. Usage of CT colonography was low. Screening rates by respondents for other malignancies in this survey was higher than that of CRC (prostate 95%, breast 97%, cervix 99%), though the most commonly encountered malignancy was breast cancer. On the contrary, for surveillance purposes, barely half of the respondents used FOBT annually or colonoscopy every 10 years, while less than half employed DCBE, sigmoidoscopy and CT colonography.ConclusionsAlthough awareness of CRC screening in this study is high, its performance is very low and highly variable in form in our region. There is a need to improve the practice of CRC screening through sensitising of medical practitioners to the need for screening, increase knowledge with regard to the relative merits of available methodologies for screening/surveillance of CRC and provide all necessary diagnostic resources and possible formulation of effective local guidelines.

Measuring Knowledge About Colorectal Cancer Among Physicians of the Southern Tier, New York

Purpose: Colorectal cancer (CRC) is the second leading cause of cancer death in the United States. A growing body of evidence indicates that the number of individuals dying of CRC could be greatly reduced through appropriate screening. Primary care physicians, resident house staff and hospitalists are various important points of entry for CRC screening. The objective of this study is to assess knowledge and provide education about CRC and its screening with the goal of implementing a research project to increase the knowledge base for enhanced translation of effective CRC screening techniques into community practice. Methods: A 1-page questionnaire consisting of 15 questions about CRC was sent out to house staff of the residency programs at Wilson memorial Hospital in Johnson City, NY, as well as hospitalists and primary care teaching attending physicians at Wilson Memorial and Binghamton General Hospital. Questions asked reflected an understanding of the basics of CRC, its screening, as well as surveillance methods and health care implications of CRC. Each question had only one possible correct answer. Results: A total of 78 questionnaires were collected. The completed questionnaires were graded and results compared among three groups. Group A being first year residents (17 surveys collected), Group B being PGY2 andPGY3 residents (24 surveys collected) and Group C being hospitalists and primary care teaching attending physicians (37 surveys collected). Regarding percentage of correct answers, the Median for Group A was 60%, group B 73%, and group C 73%. The 75th percentile for Group A was 67%, group B 80% and group C 80%. The Mean for Group A was lowest at 61%, 71% for Group B and highest for Group C at 75%. Group A had a statistically significant lower rate of correct answers compared to group B (P= 0/01) and group C (P < 0.0001). However, there was no statistically significant difference between Groups B and C (P= 0.43). Mann-Whitney test was used for this analysis. Similar results were found when the results were analyzed using ANOVA. Conclusion: These results indicate an increasing level of knowledge regarding CRC among interns, residents and attending physicians. The Attending physicians scored highest among the groups surveyed. However, it seems that the fastest rate if acquiring new knowledge is during internship. This study shows that there is still margin for improvement in knowledge base regarding CRC screening at all levels, both for the house staff and the attending physicians.

CT Colonography Can Be an Adjunct to Optical Colonoscopy in CRC Screening

CT colonography or virtual colonoscopy is a fairly new modality that has the potential to play a significant role in screening for colon cancer. CT colonography is an attractive option for two specific reasons. First, it is non-invasive and, second, it obviates the need for sedation. It thus overcomes the two major drawbacks of optical colonoscopy. CT colonography cannot be a stand-alone technique for colorectal cancer screening because, unlike conventional colonoscopy, it does not possess a therapeutic option or a definite diagnostic capability. However, CT colonography can be a cost-effective complement to traditional colonoscopy if it is reasonably priced and if appropriate cut-off levels (>6 mm polyp) are used to increase its sensitivity.

Predictors of Isolated Advanced Proximal Neoplasia of Colon: The Kasid Prospective Multicenter Study

Background: Although advanced adenomatous polyp is an ideal target of colorectal cancer screening, isolated proximal neoplasia without distal pathology would have been missed on a flexible sigmoidoscopy, an effective colorectal cancer screening technique. The aim of the study is to identify predictors of isolated advanced proximal neoplasia of colon. Methods: Data were prospectively collected from the 17,200 patients who presented for colonoscopy in 12 tertiary endoscopic centers. Information gathered included demographic characteristics including body mass index (BMI), endoscopic findings, histology, drug history of aspirin/ NSAID, and known risk factors for colorectal neoplasia. We compared the patients with isolated proximal advanced neoplasia with the patients without colon neoplasia. We defined advanced neoplasia as adenocarcinoma, high-grade dysplasia, villous polyps, or adenomas more than 11 mm. Results: Isolated advanced proximal neoplasia was found in 371 (2.2%) patients, and 6234 (36.2%) patients as a control group had no colon neoplasia. While patients older than 65 year had a risk for isolated advanced proximal neoplasia (OR = 1.38: 95% CI = 1.07-1.78; p = 0.015), male gender, obesity (BMI; >27), those who took a daily aspirin or NSAID, and a family history of colorectal cancer were not associated with an increased risk of isolated advanced proximal neoplasia. Conclusion: Because age greater than 65 year increased the risk of finding isolated proximal advanced neoplasia, colonoscopy rather than flexible sigmoidoscopy should be the first consideration as a colorectal screening in the older population. Background: Although advanced adenomatous polyp is an ideal target of colorectal cancer screening, isolated proximal neoplasia without distal pathology would have been missed on a flexible sigmoidoscopy, an effective colorectal cancer screening technique. The aim of the study is to identify predictors of isolated advanced proximal neoplasia of colon. Methods: Data were prospectively collected from the 17,200 patients who presented for colonoscopy in 12 tertiary endoscopic centers. Information gathered included demographic characteristics including body mass index (BMI), endoscopic findings, histology, drug history of aspirin/ NSAID, and known risk factors for colorectal neoplasia. We compared the patients with isolated proximal advanced neoplasia with the patients without colon neoplasia. We defined advanced neoplasia as adenocarcinoma, high-grade dysplasia, villous polyps, or adenomas more than 11 mm. Results: Isolated advanced proximal neoplasia was found in 371 (2.2%) patients, and 6234 (36.2%) patients as a control group had no colon neoplasia. While patients older than 65 year had a risk for isolated advanced proximal neoplasia (OR = 1.38: 95% CI = 1.07-1.78; p = 0.015), male gender, obesity (BMI; >27), those who took a daily aspirin or NSAID, and a family history of colorectal cancer were not associated with an increased risk of isolated advanced proximal neoplasia. Conclusion: Because age greater than 65 year increased the risk of finding isolated proximal advanced neoplasia, colonoscopy rather than flexible sigmoidoscopy should be the first consideration as a colorectal screening in the older population.

A survey of individual preference for colorectal cancer screening technique.

BackgroundDue to the low participation in colorectal cancer screening, public preference for colorectal cancer screening modality was determined.MethodsA cross-sectional survey was performed of healthy ambulatory adults in a pediatrics primary care office and neighboring church. Overall preference was ranked for each of four colorectal cancer screening modalities: Faecal Occult Blood, Fiberoptic Sigmoidoscopy, Barium Enema and Colonoscopy. Four additional domains of preference also were ranked: suspected discomfort, embarrassment, inconvenience and danger of each exam.Results80 surveys were analyzed, 57 of which were received from participants who had experienced none of the screening tests. Fecal Occult Blood Testing is significantly preferred over each other screening modality in overall preference and every domain of preference, among all subjects and those who had experienced none of the tests.ConclusionsEfforts to increase public participation in colorectal cancer screening may be more effective if undertaken in the context of public perceptions of screening choices.

CT colonography (‘virtual colonoscopy’): Is it ready for colorectal cancer screening?

CT colonography (‘virtual colonoscopy’): Is it ready for colorectal cancer screening?

Distribución de la enfermedad polipoidea en la comarca interior de Vizcaya: implicación en pruebas diagnósticas y cribado del cáncer colorrectal

The importance of colonic polyp is increasing because colorectal cancer (CRC) screening is based on their identification. However, consensus is lacking on which technique should be used in CRC screening, whether colonoscopy or other methods such as sigmoidoscopy, which shows good sensitivity only in distal segments of the colon. We studied the characteristics and localization of polyps in our environment to verify their tendency to change localization and determine the implications of this in screening. We reviewed the prevalence and characteristics of colonic polyps in 3604 patients who underwent colonoscopy for various causes in our service, as well as their distribution in 837 patients with a diagnosis of polyps who underwent complete colonoscopy. Localization proximal or distal to the splenic flexure and polyp size (less than or more than 1 cm) were analyzed. Polyps were found in 28.3% of 3604 patients (11.7% showed polyps > or = 1 cm). Of the 837 patients who underwent complete colonoscopy, proximal polyps were found in 44.9% (14.6% showed polyps > or = 1 cm), while distal polyps were found in 79.9% (30.3% showed polyps > or = 1 cm). Both proximal and distal polyps were found in 24.8%. The probability of finding both proximal and distal lesions was 31%. Proximal lesions without distal lesions were found in 20% of the patients (5.6% presented polyps > or = 1 cm), and consequently sigmoidoscopy would miss 15.6% of polyps > or = 1 cm. A relatively high percentage of patients with proximal polyps > or = 1 cm would remain undiagnosed if complete colonoscopy were only performed in patients with distal polyps. Because of the well-known increase in the frequency of proximal polyps and because a considerable number of these present without distal sentinel lesions, there are increasing arguments for considering colonoscopy as the basic technique for CRC screening.

Flexible sigmoidoscopy: an important screening option for average-risk individuals.

Colorectal cancer screening techniques should be effective, acceptable to patients, affordable, widely available, and safe. For average-risk adults aged more than 50 years who do not have significant colorectal symptoms, significant family history, or significant predisposing conditions, flexible sigmoidoscopy is an important option for reducing the risk for colorectal cancer, meeting all criteria for an effective and feasible screening modality. This article discusses evidence supporting flexible sigmoidoscopy, practical issues in implementation, and current controversies.

Rationale for colonoscopy screening and estimated effectiveness in clinical practice.

Colonoscopy screening has the highest anticipated level of effectiveness of the available colorectal cancer screening techniques. Its long-term cost-effectiveness is also comparable with or superior to other modalities. Evidence for the expected reduction in colorectal cancer incidence and mortality varies with colonoscopy screening from 50% to 90%, for reasons that are not fully understood. Maintaining a high standard of performance is critical with regard to achieving the highest level of effectiveness possible.

Stool DNA Testing to Detect Colorectal Neoplasia

An emerging technique for colorectal cancer screening is the detection of altered DNA in exfoliated cells in the stool. Mayo Clinic researchers examined the accuracy of a panel of stool assays that targeted DNA abnormalities associated with colorectal neoplasia: point mutations in the K- ras , p53 , and …