Screening CT Colonography Research Articles

Positive Oral Contrast Solution at MDCT for Suspected Acute Appendicitis in Adults: Rate of Appendiceal Luminal Filling of Normal and Inflamed Appendixes.

OBJECTIVE. The purpose of this study was to assess the rate of appendiceal filling with a positive oral contrast solution at MDCT performed for suspected acute appendicitis in adults. MATERIALS AND METHODS. We performed a retrospective review of MDCT in 684 consecutive adult patients with suspected acute appendicitis in a 19-month period. Patients were excluded if no positive oral contrast solution (500 mL each of water and polyethylene glycol and 30 mL diatrizoate) was given or if the appendix was not visible or absent. After exclusion, images of 519 patients (mean age ± SD, 37.4 ± 16.0 years; 335 women, 184 men) were reviewed for cecal contrast opacification and appendiceal filling. Imaging findings were recorded as positive or negative for acute appendicitis using all available clinical and pathologic data as a reference standard. A control series of CT colonography (CTC) screening examinations (overnight preparation with universal cecal opacification) in 2552 adults without symptoms of appendicitis was also reviewed. RESULTS. Cecal opacification was confirmed in 313/519 (60.3%) patients, with no difference between those considered to be positive (68/107, 63.6%) or negative (245/412, 59.5%) for appendicitis (p = 0.506). When positive oral contrast solution reached the cecum, appendiceal filling was seen in none of the 68 (0%) with appendicitis and in 205 of the 245 (83.7%) without appendicitis (p < 0.0001). Among CTC control subjects, appendiceal filling was similar to the cohort considered to be without appendicitis (2240/2552 [87.8%], p = 0.070). CONCLUSION. In MDCT for suspected acute appendicitis, luminal filling of the noninflamed appendix exceeds 80% when positive oral contrast solution reaches the cecum, indicating results similar to screening CTC. The appendix did not fill in proven acute appendicitis, indicating appendiceal filling may allow exclusion of appendicitis with high certainty. These results suggest positive oral contrast solution may augment diagnostic accuracy and confidence in cases of suspected acute appendicitis.

Relationships Between Health Care Disparities and Coverage Policies for Breast, Colon, and Lung Cancer Screening

Disparities in outcomes exist for breast, colon, and lung cancer among diverse populations, particularly racial and ethnic underrepresented minorities (URMs) and individuals from lower socioeconomic status. For example, blacks experience mortality rates up to about 42% higher than whites for these cancers. Furthermore, although overall death rates have been declining, the differential access to screening and care has aggravated disparities. Our purpose is to assess how the coverage policies of CMS and the United States Preventive Services Task Force (USPSTF) influence these disparities. Additionally, barriers are often encountered in accessing screening tests and receiving prompt treatment. To narrow, and potentially eliminate, outcomes disparities, CMS and USPSTF could consider revising their decision-making processes regarding coverage. Some options include (1) extending their evidence base to include observational studies that involve groups at higher risk; (2) lowering the threshold ages for screening to encompass differences in incidence; (3) CMS approving screening CT colonography coverage, which can even increase compliance with other screening tests; (4) clarifying and streamlining guidelines; (5) supporting research on improving access to screening; and (6) encouraging the development of more navigation services for URMs.

Patients' experience of screening CT colonography with reduced and full bowel preparation in a randomised trial.

To assess patients' experience of bowel preparation and procedure for screening CT colonography with reduced (r-CTC) and full cathartic preparation (f-CTC) that showed similar detection rate for advanced neoplasia in a randomised trial. Six hundred seventy-four subjects undergoing r-CTC and 612 undergoing f-CTC in the SAVE trial were asked to complete two pre-examination questionnaires-(1) Life Orientation Test - Revised (LOT-R) assessing optimism and (2) bowel preparation questionnaire-and a post-examination questionnaire evaluating overall experience of CTC screening test. Items were analysed with chi-square and t test separately and pooled. LOT-R was completed by 529 (78%) of r-CTC and by 462 (75%) of f-CTC participants and bowel preparation questionnaire by 531 (79%) subjects in the r-CTC group and by 465 (76%) in the f-CTC group. Post-examination questionnaire was completed by 525 (78%) subjects in the r-CTC group and by 453 (74%) in the f-CTC group. LOT-R average score was not different between r-CTC (14.27 ± 3.66) and f-CTC (14.54 ± 3.35) (p = 0.22). In bowel preparation questionnaire, 88% of r-CTC subjects reported no preparation-related symptoms as compared to 70% of f-CTC subjects (p < 0.001). No interference of bowel preparation with daily activities was reported in 80% of subjects in the r-CTC group as compared to 53% of subjects in the f-CTC group (p < 0.001). In post-examination questionnaire, average scores for discomfort of the procedure were not significantly different between r-CTC (3.53 ± 0.04) and f-CTC (3.59 ± 0.04) groups (p = 0.84). Reduced bowel preparation is better tolerated than full preparation for screening CT colonography. • Reduced bowel preparation is better tolerated than full preparation for screening CT colonography. • Procedure-related discomfort of screening CT colonography is not influenced by bowel preparation. • Males tolerate bowel preparation and CT colonography screening procedure better than females.

Does Nonenhanced CT-based Quantification of Abdominal Aortic Calcification Outperform the Framingham Risk Score in Predicting Cardiovascular Events in Asymptomatic Adults?

Purpose To determine if abdominal aortic calcification (AAC) at CT predicts cardiovascular events independent of Framingham risk score (FRS). Materials and Methods For this retrospective study, electronic health records for 829 asymptomatic patients (mean age, 57.9 years; 451 women, 378 men) who underwent nonenhanced CT colonography screening between April 2004 and March 2005 were reviewed for subsequent cardiovascular events; mean follow-up interval was 11.2 years ± 2.8 (standard deviation). Institutional review board approval was obtained. CT-based AAC was retrospectively quantified as a modified Agatston score by using a semiautomated tool. Kaplan-Meier curves and Cox proportional hazards models were used for time-to-event analysis; receiver operating characteristic curves and net reclassification improvement compared predictive abilities of AAC and FRS. Results An index cardiovascular event occurred after CT in 156 (19%) of 829 patients (6.7 years ± 3.5, including heart attack in 39 [5%] and death in 79 [10%]). AAC was higher in the cardiovascular event cohort (mean AAC, 3478 vs 664; P < .001). AAC was a strong predictor of cardiovascular events at both univariable and multivariable Cox modeling, independent of FRS (P < .001). Kaplan-Meier plots showed better separation with AAC over FRS. The area under the receiver operating characteristic curve (AUC) was higher for AAC than FRS at all evaluated time points (eg, AUC of 0.82 vs 0.64 at 2 years; P = .014). By using a cutoff point of 200, AAC improved FRS risk categorization with net reclassification improvement of 35.4%. Conclusion CT-based abdominal aortic calcification was a strong predictor of future cardiovascular events, outperforming the Framingham risk score. This finding suggests a potential opportunistic role in abdominal nonenhanced CT scans performed for other clinical indications. © RSNA, 2018.

CT colonography screening in extracolonic cancer survivors: impact on rates of colorectal and extracolonic findings by cancer type.

To compare the rates of colorectal and extracolonic findings at CT colonography (CTC) screening between patients with and without a personal prior history of other. Over a 160-month interval, 349 adults (mean age, 60.3 years; 67% female) with a positive history of extracolonic cancer [Ca(+)], excluding 271 patients with isolated non-melanoma skin cancers, underwent CTC screening. This study cohort was compared against 8859 controls (mean age, 57.0 years; 53% female) without a prior cancer history [Ca(-)]. Primary outcome measures included the rates of relevant colorectal (C-RADS C2-C4) and extracolonic (C-RADS E3-E4) findings at CTC. Wilcoxon rank sum test was used to test for statistical significance with post-hoc analysis by relative rate (RR). Both colorectal (C2-C4) and extracolonic (E3-E4) findings were significantly increased in the Ca(+) group versus Ca(-) control group (p = 0.0283 and 0.0236, respectively). Positive colorectal findings were most notably increased among survivors of non-small cell lung cancer (RR 3.1), head/neck cancers (RR, 3.4), and bladder cancers (RR 2.2). The proportion of C2-C4 patients undergoing intervention in the Ca(+) cohort was not significantly different than the Ca(-). Potentially relevant extracolonic findings (E3) were increased in survivors of hematogenous malignancies (RR 2.0), while likely important extracolonic findings (E4) were increased in survivors of female gynecological malignancies (RR 3.4). Relevant colorectal and extracolonic findings at CTC screening are increased in patients with a previous extracolonic cancer history, particularly among certain cancer subsets. These results may have important implications for choice of colorectal test in these patients.

Colon cancer screening with CT colonography: logistics, cost-effectiveness, efficiency and progress.

Colorectal cancer (CRC) incidence and mortality can be significantly reduced by population screening. Several different screening methods are currently in use, and this review focuses specifically on the imaging technique computed tomographic colonography (CTC). The challenges and logistics of CTC screening, as well as the importance of test accuracy, uptake, quality assurance and cost-effectiveness will be discussed. With comparable advanced adenoma detection rates to colonoscopy (the most commonly used whole-colon investigation), CTC is a less-invasive alternative, requiring less laxative, and with the potential benefit that it permits assessment of extracolonic structures. Three large-scale European trials have contributed valuable evidence supporting the use of CTC in population screening, and highlight the importance of selecting appropriate clinical management pathways based on initial CTC findings. Future research into CTC-screening will likely focus on radiologist training and CTC quality assurance, with identification of evidence-based key performance indicators that are associated with clinically-relevant outcomes such as the incidence of post-test interval cancers (CRC occurring after a presumed negative CTC). In comparison to other CRC screening techniques, CTC offers a safe and accurate option that is particularly useful when colonoscopy is contraindicated. Forthcoming cost-effectiveness analyses which evaluate referral thresholds, the impact of extra-colonic findings and real-world uptake will provide useful information regarding the feasibility of future CTC population screening.

Abstract C67: Addressing racial disparity in colorectal cancer screening with CT colonography: Experience in an African-American cohort

Abstract Purpose: Incidence and mortality from colorectal cancer (CRC) are higher among minorities, including African Americans, compared with non-Hispanic whites, and CRC screening rates for African Americans lag behind non-Hispanic whites. The purpose of this investigation was to evaluate computed tomographic (CT) colonography performance and outcome measures in an African-American cohort. Materials and Methods: Institutional review board-approved and HIPAA-compliant study. Informed consent was waived. Retrospective evaluation of the African-American cohort from the Atlanta Veterans Affairs Medical Center CT colonography screening program. Colonoscopy referral rates and histologic diagnoses were evaluated. Results: CT colonography studies (n = 2,490; mean age 59.5 years [range 50-80]; 85.5% male), were performed between 2007 and 2016. The per-patient positive rate of CT colonography was 9.8% for polyps 6-9 mm, 5.4% for polyps 10-29 mm, and 1.3% for masses &amp;gt; 30 mm. Based on CT colonography findings and patient preference, 13.9% of patients were referred to optical colonoscopy and 2.9% were referred to CT colonography follow-up. Of patients recommended to undergo colonoscopy, 80.6% completed the procedure and colonic pathology was confirmed in 83.2% thereof. Histologic diagnoses were 221 tubular adenomas (161 6-9 mm; 60 &amp;gt; 10 mm), 60 tubulovillous adenomas/villous adenomas (14 6-9 mm; 46 &amp;gt; 10 mm), 31 hyperplastic polyps (26 6-9 mm; 5 &amp;gt; 10 mm), 17 adenocarcinomas (all &amp;gt; 10 mm), 10 adenomas with high-grade dysplasia (all &amp;gt; 10 mm), and 3 serrated polyps (1 6-9 mm; 2 &amp;gt; 10 mm). The per-patient positivity rate for patients who had optical colonoscopy (n = 279) was 71.3% for adenoma, 9.7% for hyperplastic polyp, and 6.1% for adenocarcinoma. Conclusions: CT colonography is an effective screening modality for African-American adults and could potentially improve rates of colorectal screening in African-Americans. Citation Format: Todd Fibus, Courtney C. Moreno, Elizabeth A. Krupinski, David H. Kim, Perry J. Pickhardt. Addressing racial disparity in colorectal cancer screening with CT colonography: Experience in an African-American cohort [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr C67.

JOURNAL CLUB: Extracolonic Findings at CT Colonography: Systematic Review and Meta-Analysis.

The purpose of this study was to perform a systematic review and meta-analysis of published studies on CT colonography (CTC) in which extracolonic findings were assessed. A systematic review of studies of screening CTC and of CTC to evaluate symptoms (1994-June 2017) was conducted to estimate the rate of extra-colonic findings and associated additional workup recommendations. The primary outcome was potentially important extracolonic findings, defined as CT Colonography Imaging Reporting and Data System (C-RADS) category E4 or as having high clinical importance (if C-RADS was not used). Secondary outcomes included likely unimportant extracolonic findings (i.e., C-RADS category E3 or similar). Random-effects and meta-regression analyses were used to generate pooled estimates and to explore risk factors for extracolonic findings related to various cohort characteristics. Primary data were acquired from 44 studies (49,676 patients). The pooled rate of potentially important extracolonic findings was 4.9% (95% CI, 3.7-6.4%) with a high degree of heterogeneity (I2 = 95%). This estimate progressively declined over time (9% per year since 2006) and was significantly related to the reporting system (lower for C-RADS than for low, moderate, high clinical significance reporting). C-RADS-specific meta-analysis (32,746 patients) showed rates of potentially significant extracolonic findings in 2.8% (95% CI, 1.9-3.5%) of the cohort without symptoms and 5.2% (95% CI, 3.5-7.6%) of the cohort with symptoms and in 5.7% (95% CI, 3.3-9.8%) of seniors (≥ 65 years) versus 2.3% (95% CI, 1.2-4.5%) of those younger than 65 years. The overall pooled rates of recommended workup were 8.2% (95% CI, 6.6-10.1%) for all extracolonic findings and 4.0% (95% CI, 2.7-5.9%) for potentially important extracolonic findings. With use of the more robust C-RADS classification, potentially important extracolonic findings at CTC occur in less than 3% of cohorts without symptoms. For all extracolonic findings, the rate of suggested or recommended additional workup is approximately 8% but decreases to 4% for potentially important extracolonic findings.

CT Colonography Performance for the Detection of Polyps and Cancer in Adults ≥ 65 Years Old: Systematic Review and Meta-Analysis.

We sought to perform a systematic review and meta-analysis of published CT colonography (CTC) studies assessing lesion detection in senior-age (≥ 65 years old) cohorts. We conducted a systematic review of CTC studies published between January 1994 and August 2017 containing data on senior-age adults. The primary endpoint was the CTC-positive rate for large colorectal polyps (≥ 10 mm) and masses. Secondary endpoints included lesions ≥ 6 mm, proven advanced neoplasia, and colorectal cancer (CRC). Study authors were contacted for additional missing data. Random-effects and meta-regression analyses were used to generate pooled estimates and explore contributing factors. A total of 34 studies with 41,680 (18,798 senior-age) subjects were included. Pooled CTC-positive rates among senior-age patients using the 10-mm size threshold were significantly lower in cohorts of patients with no symptoms (8.2%; 95% CI, 6.0-11.1%) compared with cohorts of patients with positive fecal occult blood tests (32.8%; 95% CI, 15.4-56.7%) and other symptoms of CRC (14.0%; 95% CI, 12.0-16.1%). However, a uniformly high positive predictive value for advanced neoplasia at colonoscopy was seen for all senior-age cohorts using a 10-mm threshold (84.3%; 95% CI, 79.3-88.3%; I2 = 0.0) where such data were available. CTC sensitivity for CRC was 93.0% (95% CI, 89.0-95.0%) in senior-age patients compared with 92.0% (95% CI, 84.0-93.0%) in younger patients. Overall, CTC detection rates were higher in senior-age adults compared with younger adults. On average, one in every 12 senior-age adults without symptoms of CRC who underwent screening would be referred to colonoscopy using the 10-mm threshold, with a high yield for advanced neoplasia and high sensitivity for cancer detection. As expected, CTC-positive rates were higher in cohorts of patients 65 years old or older with symptoms of CRC. These results should help inform the Centers for Medicare & Medicaid Services regarding coverage determination of CTC screening for Medicare beneficiaries.

Role of CT colonography for primary colorectal cancer screening

Screening for colorectal cancer was introduced in the UK in 2007. It is proving effective, but uptake is relatively low in some parts of the country. In this article the authors describe the rationale behind screening and discuss the potential role for CT colonography as a screening tool.

Faecal immunochemical test in subjects not attending screening computed tomography colonography and colonoscopy in a randomized trial.

The aim of this study was to evaluate the participation and yield of the faecal immunochemical test (FIT) in nonattendees for computed tomography colonography (CTC) or optical colonoscopy (OC) screening, in the setting of a randomized trial. In the SAVE trial, 16087 individuals were randomly assigned and invited to one of four interventions for colorectal cancer screening: (i) biennial FIT for three rounds; (ii) reduced-preparation CTC; (iii) full-preparation CTC; and (iv) OC. Nonattendees of reduced-preparation CTC, full-preparation CTC and OC groups were invited to FIT. Here, we analysed the participation rate and the detection rate for cancer or advanced adenoma (advanced neoplasia) of FIT among nonattendees for reduced-preparation CTC, full-preparation CTC and OC. Nonattendees were 1721 of 2395 (71.9%) eligible invitees in the reduced-preparation CTC group, 1818 of 2430 (74.8%) in the full-preparation CTC group and 883 of 1036 (85.2%) in the OC group. Participation rates for FIT were 20.2% (347/1721) in nonattendees for reduced-preparation CTC, 21.4% (389/1818) in nonattendees for full-preparation CTC and 25.8% (228/883) in nonattendees for OC. Differences between both CTC groups and the OC group were statistically significant (P≤0.01), whereas the difference between reduced-preparation and full-preparation CTC groups was not statistically significant (P=0.38). The detection rate of FIT was not statistically significantly different among nonattendees for reduced-preparation CTC (0.9%; 3/347), nonattendees for full-preparation CTC (1.8%; 7/389) and nonattendees for OC (1.3%; 3/228) (P>0.05). Offering FIT to nonattendees for CTC or OC increases the overall participation in colorectal cancer screening and enables the detection of additional advanced neoplasia.

Addressing Racial Disparity in Colorectal Cancer Screening With CT Colonography: Experience in an African-American Cohort

BackgroundIncidence and mortality from colorectal cancer (CRC) are higher among African Americans where CRC screening rates lag behind non-Hispanic whites. The purpose of this investigation was to evaluate CT colonography (CTC) performance and outcome measures in an African-American cohort. Materials and MethodsThis study is an institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study. Retrospective evaluation of the African-American cohort from the Atlanta VA Medical Center (Decatur, Georgia) CTC screening program. Colonoscopy referral rates and histologic diagnoses were evaluated. ResultsCTC studies (n = 2490; mean age, 59.5 years [range, 50-80 years]; 85.5% male; all African American) were performed between 2007 and 2016. The per-patient CTC positive rate was 9.8% for polyps from 6 to 9 mm, 5.4% for polyps from 10 to 29 mm, and 1.3% for masses ≥ 30 mm. Based on CTC findings and patient preference, 13.9% of patients were referred to optical colonoscopy and 2.9% were referred to CTC follow-up. Of patients recommended to undergo colonoscopy, 80.6% completed the procedure and colonic pathology was confirmed in 83.2% thereof. Histologic diagnoses were 221 tubular adenomas (161 6-9 mm; 60 ≥ 10 mm), 59 tubulovillous adenomas/villous adenomas (14 6-9 mm; 45 ≥ 10 mm), 34 hyperplastic-serrated polyps (27 6-9 mm; 7 ≥ 10 mm), 18 adenocarcinomas (all ≥ 10 mm), and 11 adenomas with high-grade dysplasia (all ≥ 10 mm). The per-patient positivity rate for patients who had optical colonoscopy (n = 279) was 71.3% for adenoma, 9.7% for hyperplastic polyp, and 6.1% for adenocarcinoma. ConclusionsCTC is an effective screening modality for African-American adults and could potentially improve rates of colorectal screening in this underserved population.

Extracolonic findings and radiation at CT colonography: what the referring provider needs to know.

A better understanding of the risks and benefits of extracolonic findings and radiation dose will aid in the safe and proper implementation of CT colonography in clinical practice. The majority of extracolonic findings in screening patients are benign and can be ignored by referring physicians. Radiologists also need to be responsible in reporting extracolonic findings. Referring providers must be knowledgeable about the theoretic risks and controversies regarding the use of ionizing radiation. Screening CT colonography imparts a low-level of radiation to patients that is equivalent or less than annual background dose.

Pros and cons of multi-screen interpretation method of CT colonography for colon cancer screening

Pros and cons of multi-screen interpretation method of CT colonography for colon cancer screening

Flat Serrated Polyps at CT Colonography: Relevance, Appearance, and Optimizing Interpretation.

Serrated polyps are a recently recognized family of colonic polyps with subgroups that harbor future malignant potential. In the past, the significance of these lesions to the colorectal cancer carcinogenesis pathway was not recognized nor well understood. It is now known that serrated polyps account for approximately one-fourth of all sporadic colorectal cancers. The sessile serrated polyp (SSP) (also known as a sessile serrated adenoma [SSA]) is the main lesion of interest given its prevalence and subtle presentation. These lesions are often flat-only minimally raised from the colonic surface-and occur in the right colon. These lesions have been a likely common cause of screening failure at colonoscopy, although detection has improved with improved recognition over time. Although detection is difficult with image-based screening, serrated lesions can be detected at CT colonography. The prevalence in CT colonography screening populations mirrors the rates at colonoscopy for similar size categories. CT colonography allows identification of SSPs despite their minimally raised profile owing to the phenomenon of lesional contrast material coating. This contrast material coat aids in lesion detection by highlighting the subtle morphologic changes as well as increasing confidence that a true lesion exists despite a flat morphology. It is important to optimize contrast material coating with specific bowel preparations and other technical parameters. Radiologists should be aware of these technical and interpretation issues. Armed with this knowledge, radiologists should expect excellent results in detection of these subtle but important lesions. ©RSNA, 2017.

Flexible Sigmoidoscopy and CT Colonography Screening: Patients’ Experience with and Factors for Undergoing Screening—Insight from the Proteus Colon Trial

Purpose To compare the acceptability of computed tomographic (CT) colonography and flexible sigmoidoscopy (FS) screening and the factors predicting CT colonographic screening participation, targeting participants in a randomized screening trial. Materials and Methods Eligible individuals aged 58 years (n = 1984) living in Turin, Italy, were randomly assigned to be invited to screening for colorectal cancer with FS or CT colonography. After individuals who had died or moved away (n = 28) were excluded, 264 of 976 (27.0%) underwent screening with FS and 298 of 980 (30.4%) underwent CT colonography. All attendees and a sample of CT colonography nonattendees (n = 299) were contacted for a telephone interview 3-6 months after invitation for screening, and screening experience and factors affecting participation were investigated. Odds ratios (ORs) were computed by means of multivariable logistic regression. Results For the telephone interviews, 239 of 264 (90.6%) FS attendees, 237 of 298 (79.5%) CT colonography attendees, and 182 of 299 (60.9%) CT colonography nonattendees responded. The percentage of attendees who would recommend the test to friends or relatives was 99.1% among FS and 93.3% among CT colonography attendees. Discomfort associated with bowel preparation was higher among CT colonography than FS attendees (OR, 2.77; 95% confidence interval [CI]: 1.47, 5.24). CT colonography nonattendees were less likely to be men (OR, 0.36; 95% CI: 0.18, 0.71), retired (OR, 0.31; 95% CI: 0.13, 0.75), to report regular physical activity (OR, 0.37; 95% CI: 0.20, 0.70), or to have read the information leaflet (OR, 0.18; 95% CI: 0.08, 0.41). They were more likely to mention screening-related anxiety (mild: OR, 6.30; 95% CI: 2.48, 15.97; moderate or severe: OR, 3.63; 95% CI: 1.87, 7.04), erroneous beliefs about screening (OR, 32.15; 95% CI: 6.26, 165.19), or having undergone a recent fecal occult blood test (OR, 13.69; 95% CI: 3.66, 51.29). Conclusion CT colonography and FS screening are well accepted, but further reducing the discomfort from bowel preparation may increase CT colonography screening acceptability. Negative attitudes, erroneous beliefs about screening, and organizational barriers are limiting screening uptake; all these factors are modifiable and therefore potentially susceptible to interventions. © RSNA, 2017 Online supplemental material is available for this article.

Insurance Coverage for CT Colonography Screening: Impact on Overall Colorectal Cancer Screening Rates.

Purpose To compare overall colorectal cancer (CRC) screening rates for patients who were eligible and due for CRC screening and who were with and without insurance coverage for computed tomographic (CT) colonography for CRC screening. Materials and Methods The institutional review board approved this retrospective cohort study, with a waiver of consent. This study used longitudinal electronic health record data from 2005 through 2010 for patients managed by one of the largest multispecialty physician groups in the United States. It included 33 177 patients under age 65 who were eligible and due for CRC screening and managed by the participating health system. Stratified Cox regression models provided propensity-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the relationship between CT colonography coverage and CRC screening. Results After adjustment, patients who had insurance coverage for CT colonography and were due for CRC screening had a 48% greater likelihood of being screened for CRC by any method compared with those without coverage who were due for CRC screening (HR, 1.48; 95% CI: 1.41, 1.55). Similarly, patients with CT colonography coverage had a greater likelihood of being screened with CT colonography (HR, 8.35; 95% CI: 7.11, 9.82) and with colonoscopy (HR, 1.38; 95% CI: 1.31, 1.45) but not with fecal occult blood test (HR, 1.00; 95% CI: 0.91, 1.10) than those without such insurance coverage. Conclusion Insurance coverage of CT colonography for CRC screening was associated with a greater likelihood of a patient being screened and a greater likelihood of being screened with a test that helps both to detect cancer and prevent cancer from developing (CT colonography or colonoscopy). © RSNA, 2017.

Cost analysis of colorectal cancer screening with CT colonography in Italy.

Unit costs of screening CT colonography (CTC) can be useful for cost-effectiveness analyses and for health care decision-making. We evaluated the unit costs of CTC as a primary screening test for colorectal cancer in the setting of a randomized trial in Italy. Data were collected within the randomized SAVE trial. Subjects were invited to screening CTC by mail and requested to have a pre-examination consultation. CTCs were performed with 64- and 128-slice CT scanners after reduced or full bowel preparation. Activity-based costing was used to determine unit costs per-process, per-participant to screening CTC, and per-subject with advanced neoplasia. Among 5242 subjects invited to undergo screening CTC, 1312 had pre-examination consultation and 1286 ultimately underwent CTC. Among 129 subjects with a positive CTC, 126 underwent assessment colonoscopy and 67 were ultimately diagnosed with advanced neoplasia (i.e., cancer or advanced adenoma). Cost per-participant of the entire screening CTC pathway was €196.80. Average cost per-participant for the screening invitation process was €17.04 and €9.45 for the pre-examination consultation process. Average cost per-participant of the CTC execution and reading process was €146.08 and of the diagnostic assessment colonoscopy process was €24.23. Average cost per-subject with advanced neoplasia was €3777.30. Cost of screening CTC was €196.80 per-participant. Our data suggest that the more relevant cost of screening CTC, amenable of intervention, is related to CTC execution and reading process.

Adverse events during CT colonography for screening, diagnosis and preoperative staging of colorectal cancer: a Japanese national survey.

To retrospectively evaluate the frequencies and magnitudes of adverse events associated with computed tomographic colonography (CTC) for screening, diagnosis and preoperative staging of colorectal cancer. A Japanese national survey on CTC was administered by use of an online survey tool in the form of a questionnaire. The questions covered mortality, colorectal perforation, vasovagal reaction, total number of examinations, and examination procedures. The survey data was collated and raw frequencies were determined. Fisher's exact test was used to determine differences in event rates between groups. At 431 institutions, 147,439 CTC examinations were performed. No deaths were reported. Colorectal perforations occurred in 0.014% (21/147,439): 0.003% (1/29,823) in screening, 0.014% (13/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging. The perforation risk was significantly lower in screening than in preoperative staging CTC procedures (p = 0.028). Eighty-one per cent of perforation cases (17/21) did not require emergency surgery. Vasovagal reaction occurred in 0.081% (120/147,439): 0.111% (33/29,823) in screening, 0.088% (80/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging. The risk of colorectal perforation and vasovagal reaction in CTC is low. The frequency of colorectal perforation associated with CTC is least in the screening group and greatest in the preoperative-staging group. • The colorectal perforation rate during preoperative-staging CTC was 0.028 %. • The perforation rates for screening and diagnosis were 0.003 % and 0.014 %, respectively. • The perforation risk is significantly lower in screening than in preoperative staging. • Eighty-one per cent of perforation cases did not require emergency surgery. • Use of an automatic colon insufflator can reduce the risk of bowel perforation.

Abstract 716: Genomic classification of longitudinally observed small colorectal polyps

Abstract Introduction: Colorectal polyps are very common in elderly people with a prevalence of 15-30% reported in screening series. However, only a minority of 5% of these lesions is estimated to develop into invasive cancers, whereas others will remain stable or regress over time. In standard practice all polyps observed during colonoscopy are removed by polypectomy and therefore, knowledge about their natural history is limited. In this study, small (6-9mm) colorectal polyps were followed over time and subsequently resected during colonoscopy. Aim: The prevalence of DNA copy number alterations (CNAs), a feature associated with adenoma to carcinoma progression, was compared in polyps that morphologically progressed versus those that did not. Methods: In the CT-colonography (CTC) arm of the COCOS-trial1 small 6-9mm polyps were left in situ. After a three-year surveillance interval, growth according to CTC of 95 small polyps was measured. Based on overall volumetric change on CTC, polyps were classified as either progressed (&amp;gt;30% growth), stable (30% to -30% growth) or regressed (&amp;lt;-30% growth). From 65 resected polyps, formalin-fixed paraffin-embedded material was retrieved and reviewed by an expert pathologist (GAM). Of these polyps, 48% (31/65) progressed, 41% (27/65) remained stable and 11% (7/65) regressed. Seventy-two percent (47/65) were tubular adenomas, 14% (9/65) tubulovillous adenomas, 3% (2/65) sessile serrated lesions and 11% (7/65) hyperplastic polyps. Subsequently, the samples that yielded sufficient quality DNA were analyzed with low-coverage whole genome sequencing (HiSeq, Illumina, San Diego, CA, USA). DNA copy number status was called with the R-package QDNAseq. Results: From 50/68 resected polyps, originating from 38 individuals (mean age of 66.8 years (s.d. 7.0); 63% male), sufficient DNA was available. The mean surveillance interval of these polyps was 3.27 years (s.d. 0.29). The mean number of CNAs per sample was 0.8 (range 0-8), the most frequently observed was 13q gain (20%). No significant differences in number, or regions of CNAs were observed between polyps that progressed and the ones that did not change or diminished in size (stable or regressed). Larger polyps showed more CNAs, of which specifically 13q gain was more often present (43% in ≥10mm and 8% in &amp;lt;10mm polyps). Of note, no serrated lesions were ≥10mm. No differences in CNAs were found between the different histological subtypes. Conclusions: In a series of colorectal polyps left in situ for an average 3.27 years, no difference in prevalence of DNA copy number alterations was observed between polyps that volumetrically progressed and those that did not. Of the CNAs observed, 13q gain was most prevalent and found in 43% of the ≥10mm polyps. 1. Stoop, E. M. et al. Participation and yield of colonoscopy versus non-cathartic CT colonography in population-based screening for colorectal cancer: A randomised controlled trial. Lancet Oncol. 13, 55-64 (2012). Citation Format: Meta C. van Lanschot, Beatriz Carvalho, Charlotte J. Tutein Nolthenius, Christian R. Rausch, Ernst J. Kuipers, Jaap Stoker, Evelien Dekker, Gerrit A. Meijer. Genomic classification of longitudinally observed small colorectal polyps [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 716. doi:10.1158/1538-7445.AM2017-716