[show abstract][hide abstract] ABSTRACT: To assess the prevalence and location of advanced neoplasia in patients undergoing colonoscopy, and to compare the yield per indication.
In a multicenter colonoscopy survey (n = 18 hospitals) in the Amsterdam area (Northern Holland), data of all colonoscopies performed during a three month period in 2005 were analyzed. The location and the histological features of all colonic neoplasia were recorded. The prevalence and the distribution of advanced colorectal neoplasia and differences in yield between indication clusters were evaluated. Advanced neoplasm was defined as adenoma > 10 mm in size, with > 25% villous features or with high-grade dysplasia or cancer.
A total of 4623 eligible patients underwent a total colonoscopy. The prevalence of advanced neoplasia was 13%, with 281 (6%) adenocarcinomas and 342 (7%) advanced adenomas. Sixty-seven percent and 33% of advanced neoplasia were located in the distal and proximal colon, respectively. Of all patients with right-sided advanced neoplasia (n = 228), 51% had a normal distal colon, whereas 27% had a synchronous distal adenoma. Ten percent of all colonoscopies were performed in asymptomatic patients, 7% of whom had advanced neoplasia. In the respective procedure indication clusters, the prevalence of right-sided advanced neoplasia ranged from 11%-57%.
One out of every 7-8 colonoscopies yielded an advanced colorectal neoplasm. Colonoscopy is warranted for the evaluation of both symptomatic and asymptomatic patients.
World Journal of Gastroenterology 03/2009; 15(9):1085-92. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: To prospectively evaluate participants' experience and preference of magnetic resonance (MR) colonography with limited bowel preparation compared with full-preparation colonoscopy in participants at increased risk for colorectal cancer.
This study had institutional review board approval; all participants gave written informed consent. In this multicenter study, consecutive participants undergoing conventional colonoscopy because of a personal or family history of colorectal cancer or adenomatous polyps underwent MR colonography 2 weeks prior to colonoscopy. They all followed a low-fiber diet and were given lactulose and an oral contrast agent (fecal tagging with gadolinium) 2 days before colonography. Before imaging, spasmolytics were administered intravenously, and a water-gadolinium chelate mixture was administered rectally for distention of the colon. Breath-hold T1- and T2-weighted sequences were performed in the prone and supine positions. Participant experience in terms of, for example, pain and burden was determined by using a five-point scale and was evaluated with a Wilcoxon signed rank test; participant preference was determined by using a seven-point scale and was evaluated with the chi2 statistic after dichotomizing.
Two hundred nine participants (77 women, 132 men; mean age, 58 years; range, 23-84 years) were included. One hundred forty-eight participants received sedatives (midazolam) and/or analgesics (fentanyl) during colonoscopy. Participants rated the MR colonography bowel preparation as less burdensome (P<.001) compared with the colonoscopy bowel preparation (10% and 71% of participants rated the respective examinations moderately to extremely burdensome). Participants also experienced less pain at MR colonography (P<.001) and found MR colonography less burdensome (P<.001). Immediately after both examinations, 69% of participants preferred MR colonography, 22% preferred colonoscopy, and 9% were indifferent (P<.001, 69% vs 22%). After 5 weeks, 65% preferred MR colonography and 26% preferred colonoscopy (P<.001).
Participants preferred MR colonography without extensive cleansing to colonoscopy immediately after both examinations and 5 weeks later. Experience of the bowel preparation and of the procedure was rated better.
[show abstract][hide abstract] ABSTRACT: To prospectively evaluate the diagnostic performance of magnetic resonance (MR) colonography by using limited bowel preparation in patients with polyps of 10 mm or larger in diameter in a population at increased risk for colorectal cancer, with optical colonoscopy as the reference standard.
The institutional review boards of all three hospitals approved the study. All patients provided written informed consent. In this multicenter study, patients undergoing colonoscopy because of a personal or family history of colorectal cancer or adenomatous polyps were included. Two blinded observers independently evaluated T1- and T2-weighted MR colonographic images obtained with limited bowel preparation (bright-lumen fecal tagging) for the presence of polyps. The limited bowel preparation consisted of a low-fiber diet, with ingestion of lactulose and an oral gadolinium-based contrast agent (with all three major meals) starting 48 hours prior to imaging. Results were verified with colonoscopic outcomes. Patient sensitivity, patient specificity, polyp sensitivity, and interobserver agreement for lesions of 10 mm or larger were calculated for both observers individually and combined.
Two hundred patients (mean age, 58 years; 128 male patients) were included; 41 patients had coexistent symptoms. At colonoscopy, 12 patients had 22 polyps of 10 mm or larger. Per-patient sensitivity was 58% (seven of 12) for observer 1, 67% (eight of 12) for observer 2, and 75% (nine of 12) for both observers combined for polyps of 10 mm or larger. Per-patient specificity was 95% (178 of 188) for observer 1, 97% (183 of 188) for observer 2, and 93% (175 of 188) for both observers combined. Per-polyp sensitivity was 55% (12 of 22) for observer 1, 50% (11 of 22) for observer 2, and 77% (17 of 22) for both observers combined. Interobserver agreement was 93% for identification of patients with lesions of 10 mm or larger.
In patients at increased risk for colorectal cancer, specificity of MR colonography by using limited bowel preparation was high, but sensitivity was modest.
[show abstract][hide abstract] ABSTRACT: To prospectively evaluate short- and midterm patient preference of computed tomographic (CT) colonography relative to colonoscopy in patients at increased risk for colorectal cancer and to elucidate determinants of preference.
Consecutive patients at increased risk for colorectal cancer underwent CT colonography prior to scheduled colonoscopy. Patient experience and preference were assessed both directly after the examinations and 5 weeks after the examinations. Differences in pain, embarrassment, discomfort, and preference were assessed with the Wilcoxon signed rank sum test or a binomial test. Potential determinants of preference were investigated with logistic regression analyses.
Data for 249 patients were included. Fewer patients experienced severe or extreme pain during CT colonography (seven [3%] of 245) than during colonoscopy (81 [34%] of 241) (P < .001). Directly after both examinations, 168 (71%) of 236 patients preferred CT colonography; 5 weeks later, 141 (61%) of 233 patients preferred CT colonography (P < .001). Initially, a painful colonoscopy examination (odds ratio, 0.17; 95% confidence interval [CI]: 0.08, 0.38) was a determinant of CT colonography preference. Similarly, a painful (odds ratio, 3.70; 95% CI: 1.54, 8.92) or an embarrassing (odds ratio, 4.46; 95% CI: 1.18, 16.88) CT colonography examination was a determinant of colonoscopy preference. After 5 weeks, the presence of polyps emerged as a determinant of colonoscopy preference (odds ratio, 1.94; 95% CI: 1.02, 3.70), while the role of experiences waned.
Patients preferred CT colonography to colonoscopy; however, this preference decreased in time, while outcome considerations gradually replaced temporary experiences of inconvenience.
[show abstract][hide abstract] ABSTRACT: To date, computed tomographic (CT) colonography has been compared with an imperfect test, colonoscopy, and has been mainly assessed in patients with positive screening test results or symptoms. Therefore, the available data may not apply to screening of patients with a personal or family history of colorectal polyps or cancer (increased risk). We prospectively investigated the ability of CT colonography to identify individuals with large (>or=10 mm) colorectal polyps in consecutive patients at increased risk for colorectal cancer.
A total of 249 consecutive patients at increased risk for colorectal cancer underwent CT colonography before colonoscopy. Two reviewers interpreted CT colonography examinations independently. Sensitivity, specificity, and predictive values were determined after meticulous matching of CT colonography with colonoscopy. Unexplained large false-positive findings were verified with a second-look colonoscopy.
In total, 31 patients (12%) had 48 large polyps at colonoscopy. This included 8 patients with 8 large polyps that were overlooked initially and detected at the second-look colonoscopy. In 6 of 8 patients, the missed polyp was the only large lesion. With CT colonography, 84% of patients (26/31) with large polyp(s) were identified, paired for a specificity of 92% (200-201/218). Positive and negative predictive values were 59%-60% (26/43-44) and 98% (200-201/205-206), respectively. CT colonography detected 75%-77% (36-37/48) of large polyps, with 9 of the missed lesions being flat.
CT colonography and colonoscopy have a similar ability to identify individuals with large polyps in patients at increased risk for colorectal cancer. The large proportion of missed flat lesions warrants further study.