Colorectal Neoplasia In Asymptomatic Adults Research Articles

Derivation and validation of a predictive model for advanced colorectal neoplasia in asymptomatic adults

ObjectiveKnowing risk for advanced colorectal neoplasia (AN) could help patients and providers choose among screening tests, improving screening efficiency and uptake. We created a risk prediction model for AN to...

Derivation and Validation of a Predictive Model for Advanced Colorectal Neoplasia in Asymptomatic Adults

Derivation and Validation of a Predictive Model for Advanced Colorectal Neoplasia in Asymptomatic Adults

Derivation and Validation of a Scoring System to Stratify Risk for Advanced Colorectal Neoplasia in Asymptomatic Adults: A Cross-sectional Study.

Several methods are recommended equally strongly for colorectal cancer screening in average-risk persons. Risk stratification would enable tailoring of screening within this group, with less invasive tests (sigmoidoscopy or occult blood tests) for lower-risk persons and colonoscopy for higher-risk persons. To create a risk index for advanced neoplasia (colorectal cancer and adenomas or serrated polyps ≥1.0 cm, villous histology, or high-grade dysplasia) anywhere in the colorectum, using the most common risk factors for colorectal neoplasia. Cross-sectional study. Multiple endoscopy units, primarily in the Midwest. Persons aged 50 to 80 years undergoing initial screening colonoscopy (December 2004 to September 2011). Derivation and validation of a risk index based on points from regression coefficients for age, sex, waist circumference, cigarette smoking, and family history of colorectal cancer. Among 2993 persons in the derivation set, prevalence of advanced neoplasia was 9.4%. Risks for advanced neoplasia in persons at very low, low, intermediate, and high risk were 1.92% (95% CI, 0.63% to 4.43%), 4.88% (CI, 3.79% to 6.18%), 9.93% (CI, 8.09% to 12.0%), and 24.9% (CI, 21.1% to 29.1%), respectively (P < 0.001). Sigmoidoscopy to the descending colon in the low-risk groups would have detected 51 of 70 (73% [CI, 61% to 83%]) advanced neoplasms. Among 1467 persons in the validation set, corresponding risks for advanced neoplasia were 1.65% (CI, 0.20% to 5.84%), 3.31% (CI, 2.08% to 4.97%), 10.9% (CI, 8.26% to 14.1%), and 22.3% (CI, 16.9% to 28.5%), respectively (P < 0.001). Sigmoidoscopy would have detected 21 of 24 (87.5% [CI, 68% to 97%]) advanced neoplasms. Split-sample validation; results apply to first-time screening. This index stratifies risk for advanced neoplasia among average-risk persons by identifying lower-risk groups for which noncolonoscopy strategies may be effective and efficient and a higher-risk group for which colonoscopy may be preferred. National Cancer Institute, Walther Cancer Institute, Indiana University Simon Cancer Center, and Indiana Clinical and Translational Sciences Institute.

Derivation and Validation of a Scoring System to Stratify Risk for Advanced Colorectal Neoplasia in Asymptomatic Adults: A Cross-sectional Study

Derivation and Validation of a Scoring System to Stratify Risk for Advanced Colorectal Neoplasia in Asymptomatic Adults: A Cross-sectional Study

Risk for Advanced Colorectal Neoplasia in Asymptomatic Adults is Effectively Stratified by Phenotypic Features: Presidential Poster

Purpose: While colorectal cancer (CRC) screening is effective and cost-effective for reducing CRC incidence and mortality, it is underutilized, inefficient, and costly. The ability to stratify risk for advanced neoplasia (AN) could improve screening efficiency and uptake. Several risk factors for AN are not used in practice because of inability to integrate them to produce a risk estimate. Study aim is to create a riskstratifying index for AN (CRC, advanced adenomas, serrated polyps ≥ 1 cm). Methods: We measured socio-demographic and physical features, medical and family history, and lifestyle factors in 50-80 year olds who underwent 1st-time screening colonoscopy between 12/2004 and 9/2011, linking these factors to endoscopic and histologic findings. Using best-subsets logistic regression, we derived a risk equation on a randomly selected 2/3s of the sample. The model selected was based on optimal statistical metrics, including Mallow's C and frequency with which each variable appeared in the top 20 models. Based on model coefficients, we assigned points to each variable to create a risk score (range, -13 to 13). Scores with comparable risk magnitudes were collapsed into risk categories. The model was then tested on the remaining sample. Results: Among 3,025 subjects in the derivation set (mean age 57.3 ± 6.5 years; 52% women), prevalence of AN was 9.4% (including 26 CRCs). Model variables include age, sex, smoking, ethanol use, diet, marital status, NSAID and aspirin use, physical activity, education level, and metabolic syndrome (P-value for fit = 0.09; c-statistic = 0.78). Respective risks of AN in the low- (scores of -13 to -5), intermediate- (scores of -4 to 2) and high- (scores of 3 to 13) were 1.50% (95%, 0.07-2.8%), 6.94%, and 27.3% (P-value for trend < 0.001), with respective cohort proportions of 23%, 59%, and 18%. Ten low-risk subjects had AN (0 CRCs, 6 distal). Based on finding a distal sentinel polyp, sigmoidoscopy would have detected 7 (70%) ANs. Among the 1,475 subjects in the test set (mean age 57.2 ± 6.5 years; 52% women), AN prevalence was 8.4%. Risk of AN in the low-risk subgroup was 2.73% (CI, 1.25-5.11%) and was 5.57% and 25.4% in the intermediate- and high-risk subgroups, respectively (P<0.001), with cohort proportions of 23%, 59%, and 18%. Nine low-risk subjects had AN (0 CRCs, 5 distal, 6 detectable by sigmoidoscopy). Conclusion: This risk index effectively stratifies the risk for AN among asymptomatic adults, identifying a low-risk subgroup of 23% that may be screened effectively and efficiently with tests other than colonoscopy and a high-risk subgroup of 18% for which colonoscopy may be preferred. If validated in other settings, this index could increase the efficiency and uptake of CRC screening.

760 A Risk Index to Stratify the Risk of Advanced Colorectal Neoplasia in Asymptomatic Adults

760 A Risk Index to Stratify the Risk of Advanced Colorectal Neoplasia in Asymptomatic Adults

Magnetic Resonance Colonography for the Detection of Colorectal Neoplasia in Asymptomatic Adults

Colonoscopy is the preferred screening test for colorectal neoplasia; the fecal occult blood test (FOBT) detects neoplasias with low levels of sensitivity. Computed tomographic colonography detects neoplasias with high levels of sensitivity but involves exposure to radiation. We investigated whether magnetic resonance colonography (MRC) can be used to screen for colorectal adenomas and cancers. We analyzed data from 286 asymptomatic adults (40-82 years old) who underwent 3 Tesla MRC and colonoscopic examinations on the same day. FOBT was performed before bowel preparation. Colonoscopists were initially blinded to the findings on MRC and unblinded after withdrawal from the respective segments. Sensitivities for adenoma and per-patient sensitivities and specificities were calculated based on the unblinded results of colonoscopy. We detected 133 adenomas and 2 cancers in 86 patients; 37 adenomas were ≥6 mm, and 20 adenomas were advanced. Sensitivities of MRC and colonoscopy for adenomas ≥6 mm were 78.4% (95% confidence interval [CI], 61.8-90.2) and 97.3% (95% CI, 85.8-99.9); for advanced adenomas these values were 75% (95% CI, 50.9-91.3) and 100% (95% CI, 83.2-100.0), respectively. MRC identified 87.1% (95% CI, 70.2-96.4), colonoscopy 96.8% (95% CI, 83.3-99.9), and FOBT 10.0% (95% CI, 2.1-26.5) of individuals with adenomas ≥6 mm and 83.8% (95% CI, 58.6-96.4), 100% (95% CI, 81.5-100.0), and 17.6% (95% CI, 3.8-43.4) of individuals with advanced neoplasia. Specificities of MRC, colonoscopy, and FOBT for individuals with adenomas ≥6 mm were 95.3% (95% CI, 91.9-97.5), 96.9% (95% CI, 93.9-98.6), and 91.8% (95% CI, 87.6-94.9), respectively. 3 Tesla MRC detects colorectal adenomas ≥6 mm and advanced neoplasia with high levels of sensitivity and specificity. Although MRC detects colorectal neoplasia with lower levels of sensitivity than colonoscopy, it strongly outperforms one-time FOBT.

Magnetic resonance colonography for the detection of colorectal neoplasia in asymptomatic adults.

Magnetic resonance colonography for the detection of colorectal neoplasia in asymptomatic adults.

Validation of a Risk Index for Advanced Proximal Colorectal Neoplasia in Asymptomatic Adults

Validation of a Risk Index for Advanced Proximal Colorectal Neoplasia in Asymptomatic Adults

Building a CT Colonography Program: Necessary Ingredients for Reimbursement and Clinical Success

Since its inception in April of 2004, the computed tomographic (CT) colonography clinical program at our institution has rapidly grown into a bustling viable enterprise. This editorial will detail our philosophies and actions in building a successful CT colonography program, which has already become an integral part of colon cancer screening at our center. The concept of success in this editorial refers to the following: (a) the ability to provide noninvasive yet effective colon cancer screening through the use of CT colonography; (b) the ability to interweave CT colonography into an already established optical colonoscopy program while maintaining cooperation and collegiality with gastroenterology colleagues; (c) the ability to provide a patient-friendly and seamless service for colorectal screening, including same-day polyp removal with optical colonoscopy, if needed; and (d) the ability to receive third-party reimbursement for screening CT colonography. The factors necessary for success can occur at various levels. Broadly, there is a national level at which the current hurdles of demonstrating uniform clinical efficacy and addressing the continued resistance to reimbursement predominate. The local level relates to the milieu of hospitals and third-party payers that shapes the regional health care environment. Finally, there is the institutional level, at which equipment, personnel, hospital administration support, and clinical colleague relationships are critical. This editorial will deal with each of these three areas, taking note that the individual practitioner has more direct influence at the local and institutional levels. We will also provide a brief update on the current status of our CT colonography clinical program.

Virtual colonoscopy detected colorectal polyps in asymptomatic patients with average risk of colorectal neoplasia

Pickhardt PJ, Choi JR, Hwang I, et al . Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults. N Engl J Med 2003;349:2191–200. [OpenUrl][1][CrossRef][2][PubMed][3][Web of Science][4] Q...

Virtual colonoscopy—finally a credible contender

Virtual colonoscopy—finally a credible contender

Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults

Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults

“Virtual colonoscopy” for colorectal neoplasia

A computed tomography scan that provides a “virtual colonoscopy” of the large intestine appears just as adept at detecting colorectal neoplasia as standard optical colonoscopy. Virtual colonoscopy is a rapidly evolving technique in which data from computed tomography (CT) are used to generate both 2-dimensional and 3-dimensional displays of the colon and rectum. In a report in the December 4 issue of The New England Journal of Medicine, a team led by researchers from the National Naval Medical Center in Bethesda, Maryland, says “This minimally invasive method for the examination of the whole colon, also called CT colonography, could provide an attractive alternative for use in widespread screening, since it requires no intravenous administration of sedatives, analgesia, or recovery time.” While the report notes that the performance characteristics of virtual colonoscopy have been encouraging in trials involving cohorts of patients with an increased number of polyps, “the results in populations with a lower prevalence of polyps have been disappointing, and the large studies conducted to date have not evaluated an asymptomatic, average-risk screening population.” In the new study, 1233 asymptomatic adults (728 men and 505 women; mean age, 57.8 years) underwent same-day virtual and optical colonoscopy. Radiologists used the 3-dimensional endoluminal display for the initial detection of polyps on CT virtual colonoscopy. For the initial examination of each colonic segment, the colonoscopists were unaware of the findings on virtual colonoscopy, which were revealed to them before any subsequent reexamination. The sensitivity and specificity of virtual colonoscopy and the sensitivity of optical colonoscopy were calculated with the use of the findings of the final, unblinded optical colonoscopy as the reference standard. The sensitivity of virtual colonoscopy for adenomatous polyps was 93.8% for polyps at least 10 mm in diameter, 93.9% for polyps at least 8 mm in diameter, and 88.7% for polyps at least 6 mm in diameter. The sensitivity of optical colonoscopy for adenomatous polyps was 87.5%, 91.5%, and 92.3% for the 3 sizes of polyps, respectively. The specificity of virtual colonoscopy for adenomatous polyps was 96.0% for polyps at least 10 mm in diameter, 92.2% for polyps at least 8 mm in diameter, and 79.6% for polyps at least 6 mm in diameter. Two polyps were malignant; both were detected on virtual colonoscopy, and one of them was missed on optical colonoscopy before the results on virtual colonoscopy were revealed. “Our results show that virtual colonoscopy with a 3-dimensional emphasis is an effective tool for the detection of colorectal neoplasia in asymptomatic adults with an average risk of colorectal cancer. These findings support the concept of a colon-screening center that offers virtual colonoscopy to patients, with the opportunity for same-day or next-day therapeutic optical colonoscopy, if needed. Such an endeavor would require close collaboration among radiologists and gastroenterologists,” the authors conclude. An editorial in the Journal by Dr. Martina M. Morrin, Assistant Professor of Radiology and Dr. Thomas LaMont, Chief of Gatroenterology at Beth Israel-Deaconess Medical Center in Boston, highlight several factors that might account for the new findings: (1) the use of water-soluble and barium contrast material to tag residual fluid and retained stool, thereby enabling the imaging software to digitally remove all opacified fluid and stool from the image by a process known as electronic cleansing. “All virtual colonoscopic studies were performed with the use of multidetector CT scanners, which permit faster, higher-resolution imaging than the single-detector scanners that have been used previously,” they state; (2) the exclusion of hyperplastic polyps may have resulted in higher estimates of the sensitivity of virtual colonoscopy. “At the same time, the classification of hyperplastic polyps as false positive findings resulted in lower estimates of the specificity of virtual colonoscopy,” Morrin and Lamont write; and (3) the use of a primary 3-dimensional approach for the detection of polyps rather than the currently accepted 2-dimensional approach with 3-dimensional imaging used only to resolve uncertainties may have contributed to their high detection rates. Still, the editorial writers say the performance of virtual colonoscopy described in the report “is impressive, with detection rates for adenomas similar to those achieved with conventional colonoscopy. “If the results of this well-designed study are reproducible on a wider scale, and if the important questions regarding the appropriate size threshold and the surveillance of smaller polyps can be resolved, then screening virtual colonoscopy is ready for prime time.” For more details, see N Engl J Med, (December 4), 2003;349:2191–2200.