Understanding the contribution of family history to colorectal cancer risk and its clinical implications: A state-of-the-science review.

Persons with a family history (FH) of colorectal cancer (CRC) or adenomas that are not due to known hereditary syndromes have an increased risk for CRC. An understanding of these risks, screening recommendations, and screening behaviors can inform strategies for reducing the CRC burden in these families. A comprehensive review of the literature published within the past 10 years has been performed to assess what is known about cancer risk, screening guidelines, adherence and barriers to screening, and effective interventions in persons with an FH of CRC and to identify FH tools used to identify these individuals and inform care. Existing data show that having 1 affected first-degree relative (FDR) increases the CRC risk 2-fold, and the risk increases with multiple affected FDRs and a younger age at diagnosis. There is variability in screening recommendations across consensus guidelines. Screening adherence is <50% and is lower in persons under the age of 50 years. A provider's recommendation, multiple affected relatives, and family encouragement facilitate screening; insufficient collection of FH, low knowledge of guidelines, and poor family communication are important barriers. Effective interventions incorporate strategies for overcoming barriers, but these have not been broadly tested in clinical settings. Four strategies for reducing CRC in persons with familial risk are suggested: 1) improving the collection and utilization of the FH of cancer, 2) establishing a consensus for screening guidelines by FH, 3) enhancing provider-patient knowledge of guidelines and communication about CRC risk, and 4) encouraging survivors to promote screening within their families and partnering with existing screening programs to expand their reach to high-risk groups. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2633-2645. © 2016 American Cancer Society.

Clinical use of CT colonography for colorectal cancer screening in military training facilities and potential impact on HEDIS measures.

PURPOSE: The National Committee for Quality Assurance developed the Healthcare Effectiveness Data and Information Set(®) (HEDIS(®)) to provide quality measures for the evaluation of standards of medical care across health plans. Screening for colorectal cancer (CRC) has been shown to increase the detection of early-stage disease and reduce mortality. Current HEDIS measures for CRC screening include fecal occult blood testing, flexible sigmoidoscopy, and colonoscopy. The aim of this analysis was to quantify the use of CT colonography (CTC) for CRC screening and demonstrate the potential impact of including CTC as a HEDIS-acceptable screening modality. METHODS: Demographic and health care utilization data from the Military Health System Population Health Portal for January 1, 2005, through December 31, 2010, for individuals aged 50 to 75, were analyzed to determine the degree of overall utilization of CTC. Screening compliance for CRC per HEDIS was also estimated, and the incremental impact of adding HEDIS-eligible patients who had undergone CTC as their only CRC screening test was then evaluated for two similarly sized, regional Navy medical centers. RESULTS: Across all sites (10 Army, 4 Navy, 3 Air Force), 17,187 CTC studies were performed, with increasing utilization during the 6-year study period. At the two Navy medical centers, screening compliance ranged from 33.8% to 67.9% without CTC and from 33.8% to 84.0% with CTC. CONCLUSIONS: CTC is actively being used for CRC screening across military treatment facilities. The inclusion of CTC as a HEDIS-compliant CRC screening test has the potential to significantly increase health care system compliance for National Committee for Quality Assurance CRC screening measures.

Rescreening of persons with a negative colonoscopy result: results from a microsimulation model.

BACKGROUND: Persons with a negative result on screening colonoscopy are recommended to repeat the procedure in 10 years. OBJECTIVE: To assess the effectiveness and costs of colonoscopy versus other rescreening strategies after an initial negative colonoscopy result. DESIGN: Microsimulation model. DATA SOURCES: Literature and data from the Surveillance, Epidemiology, and End Results program. TARGET POPULATION: Persons aged 50 years who had no adenomas or cancer detected on screening colonoscopy. TIME HORIZON: Lifetime. PERSPECTIVE: Societal. INTERVENTION: No further screening or rescreening starting at age 60 years with colonoscopy every 10 years, annual highly sensitive guaiac fecal occult blood testing (HSFOBT), annual fecal immunochemical testing (FIT), or computed tomographic colonography (CTC) every 5 years. OUTCOME MEASURES: Lifetime cases of colorectal cancer, life expectancy, and lifetime costs per 1000 persons, assuming either perfect or imperfect adherence. RESULTS OF BASE-CASE ANALYSIS: Rescreening with any method substantially reduced the risk for colorectal cancer compared with no further screening (range, 7.7 to 12.6 lifetime cases per 1000 persons [perfect adherence] and 17.7 to 20.9 lifetime cases per 1000 persons [imperfect adherence] vs. 31.3 lifetime cases per 1000 persons with no further screening). In both adherence scenarios, the differences in life-years across rescreening strategies were small (range, 30 893 to 30 902 life-years per 1000 persons [perfect adherence] vs. 30 865 to 30 869 life-years per 1000 persons [imperfect adherence]). Rescreening with HSFOBT, FIT, or CTC had fewer complications and was less costly than continuing colonoscopy. RESULTS OF SENSITIVITY ANALYSIS: Results were sensitive to test-specific adherence rates. LIMITATION: Data on adherence to rescreening were limited. CONCLUSION: Compared with the currently recommended strategy of continuing colonoscopy every 10 years after an initial negative examination, rescreening at age 60 years with annual HSFOBT, annual FIT, or CTC every 5 years provides approximately the same benefit in life-years with fewer complications at a lower cost. Therefore, it is reasonable to use other methods to rescreen persons with negative colonoscopy results. PRIMARY FUNDING SOURCE: National Cancer Institute.

ACR Colon Cancer Committee white paper: status of CT colonography 2009.

PURPOSE: To review the current status and rationale of the updated ACR practice guidelines for CT colonography (CTC). METHODS: Clinical validation trials in both the United States and Europe are reviewed. Key technical aspects of the CTC examination are emphasized, including low-dose protocols, proper insufflation, and bowel preparation. Important issues of implementation are discussed, including training and certification, definition of the target lesion, reporting of colonic and extracolonic findings, quality metrics, reimbursement, and cost-effectiveness. RESULTS: Successful validation trials in screening cohorts both in the United States with ACRIN and in Germany demonstrated sensitivity > or = 90% for patients with polyps >10 mm. Proper technique is critical, including low-dose techniques in screening cohorts, with an upper limit of the CT dose index by volume of 12.5 mGy per examination. Training new readers includes the requirement of interactive workstation training with 2-D and 3-D image display techniques. The target lesion is defined as a polyp > or = 6 mm, consistent with the American Cancer Society joint guidelines. Five quality metrics have been defined for CTC, with pilot data entered. Although the CMS national noncoverage decision in May 2009 was a disappointment, multiple third-party payers are reimbursing for screening CTC. Cost-effective modeling has shown CTC to be a dominant strategy, including in a Medicare cohort. CONCLUSION: Supported by third-party payer reimbursement for screening, CTC will continue to further transition into community practice and can provide an important adjunctive examination for colorectal screening.

CT colonography: investigation of the optimum reader paradigm by using computer-aided detection software.

PURPOSE: To prospectively compare the diagnostic performance and time efficiency of both second and concurrent computer-aided detection (CAD) reading paradigms for retrospectively obtained computed tomographic (CT) colonography data sets by using consensus reading (three radiologists) of colonoscopic findings as a reference standard. MATERIALS AND METHODS: Ethical permission, HIPAA compliance (for U.S. institutions), and patient consent were obtained from all institutions for use of CT colonography data sets in this study. Ten radiologists each read 25 CT colonography data sets (12 men, 13 women; mean age, 61 years) containing 69 polyps (28 were 1-5 mm, 41 were >or=6 mm) by using workstations integrated with CAD software. Reading was randomized to either "second read" CAD (applied only after initial unassisted assessment) or "concurrent read" CAD (applied at the start of assessment). Data sets were reread 6 weeks later by using the opposing paradigm. Polyp sensitivity and reading times were compared by using multilevel logistic and linear regression, respectively. Receiver operating characteristic (ROC) curves were generated. RESULTS: Compared with the unassisted read, odds of improved polyp (>or=6 mm) detection were 1.5 (95% confidence interval [CI]: 1.0, 2.2) and 1.3 (95% CI: 0.9, 1.9) by using CAD as second and concurrent reader, respectively. Detection odds by using CAD concurrently were 0.87 (95% CI: 0.59, 1.3) and 0.76 (95% CI: 0.57, 1.01) those of second read CAD, excluding and including polyps 1-5 mm, respectively. The concurrent read took 2.9 minutes (95% CI: -3.8, -1.9) less than did second read. The mean areas under the ROC curve (95% CI) for the unassisted read, second read CAD, and concurrent read CAD were 0.83 (95% CI: 0.78, 0.87), 0.86 (95% CI: 0.82, 0.90), and 0.88 (95% CI: 0.83, 0.92), respectively. CONCLUSION: CAD is more time efficient when used concurrently than when used as a second reader, with similar sensitivity for polyps 6 mm or larger. However, use of second read CAD maximizes sensitivity, particularly for smaller lesions.

Linear polyp measurement at CT colonography: in vitro and in vivo comparison of two-dimensional and three-dimensional displays.

PURPOSE: To compare the accuracy of polyp measurement at computed tomographic (CT) colonography by using two-dimensional (2D) multiplanar reformation (MPR) and three-dimensional (3D) endoluminal displays obtained both in a colon phantom and at clinical examinations. MATERIALS AND METHODS: This HIPAA-compliant study had institutional review board approval, and all patients provided signed informed consent, both of which allowed for additional retrospective evaluation. Two-dimensional and 3D CT colonography displays were generated from data obtained in an in vitro colon phantom that contained 10 6-13-mm synthetic polyps and from data obtained at in vivo clinical CT colonography examinations performed in 10 patients (five men, five women; mean age, 56.3 years) with proved polyps (size range, 7-25 mm). The reference standard for in vivo polyp size was optical colonoscopic measurement with a calibrated linear probe. Polyps were measured at CT colonography with 2D MPR and 3D endoluminal displays and electronic calipers by four radiologists who were unaware of the reference size measurements. The largest of the three 2D MPR measurements was considered the "optimized" 2D projection. Statistical analysis was performed with Wilcoxon signed rank, repeated-measures analysis of variance, and paired t testing. RESULTS: For the phantom, the mean errors (differences between actual polyp size and that measured at CT colonography) for 2D transverse, 2D coronal, and 3D endoluminal displays were 1.6 mm +/- 0.8 (standard deviation), 1.4 mm +/- 0.7, and 0.8 mm +/- 0.5, respectively. For in vivo polyp measurements, the mean errors for 2D transverse, 2D coronal, 2D sagittal, and 3D displays were 4.4 mm +/- 3.5, 3.8 mm +/- 3.3, 4.6 mm +/- 3.0, and 1.9 mm +/- 1.6, respectively. The 2D measurements underestimated actual polyp sizes in all cases. The differences in mean errors between 2D MPR and 3D endoluminal measurements were significant (P < .05). When the optimized 2D view was considered for in vivo measurement, the mean error decreased to 3.0 mm +/- 2.6 (P = .2). CONCLUSION: Linear polyp measurement on 3D endoluminal views was significantly more accurate than measurement on 2D transverse, coronal, or sagittal views, both in vitro and in vivo, for the CT colonography system evaluated. Use of the optimized 2D view substantially reduced 2D measurement error and may be valuable when used in conjunction with 3D measurement.

Computed tomography colonography: automated diameter and volume measurement of colonic polyps compared with a manual technique--in vitro study.

OBJECTIVE: To investigate inter- and intraobserver agreement of automated measurement of polyp diameter in vitro. METHODS: Two phantoms ("QRM" and "Whiting") containing simulated polyps of known diameter and volume were scanned using 16-detector row computed tomography. Two observers estimated polyp diameter using 3 methods: software calipers ("manual"), freehand boundary identification ("semiautomatic"), and automated software segmentation ("fully automatic"). RESULTS: Intraobserver 95% limits of agreement for diameter were narrowest for the fully automatic method (QRM span: 0.39 mm, 0.48 mm; Whiting span: 0.24 mm, 0 mm). Manual estimates were approximately 10 times wider (QRM span: 3.57 mm, 3.21 mm; Whiting span: 3.2 mm, 2.02 mm). Volume estimates were narrowest for the fully automatic method (span: 24.2 mm, 24.1 mm vs. 97.9 mm, 102.9 mm for semiautomatic measurement). Interobserver agreement for diameter was narrowest for the fully automatic method (QRM span: 0.12 mm, Whiting span: 0.16 mm), with the manual method approximately 18 times wider (QRM span: 2.87 mm, Whiting span: 2.18 mm). CONCLUSION: Fully automated measurement of polyp diameter and volume is technically feasible and results in superior inter- and intraobserver agreement.

Computerized tomographic colonography: performance evaluation in a retrospective multicenter setting.

BACKGROUND & AIMS: No multicenter study has been reported evaluating the performance and interobserver variability of computerized tomographic colonography. The aim of this study was to assess the accuracy of computerized tomographic colonography for detecting clinically important colorectal neoplasia (polyps >or=10 mm in diameter) in a multi-institutional study. METHODS: A retrospective study was developed from 341 patients who had computerized tomographic colonography and colonoscopy among 8 medical centers. Colonoscopy and pathology reports provided the standard. A random sample of 117 patients, stratified by criterion standard, was requested. Ninety-three patients were included (47% with polyps >or=10 mm; mean age, 62 years; 56% men; 84% white; 40% reported colorectal symptoms; 74% at increased risk for colorectal cancer). Eighteen radiologists blinded to the criterion standard interpreted computerized tomography colonography examinations, each using 2 of 3 different software display platforms. RESULTS: The average area under the receiver operating characteristic curve for identifying patients with at least 1 lesion >or=10 mm was 0.80 (95% lower confidence bound, 0.74). The average sensitivity and specificity were 75% (95% lower confidence bound, 68%) and 73% (95% lower confidence bound, 66%), respectively. Per-polyp sensitivity was 75%. A trend was observed for better performance with more observer experience. There was no difference in performance across software display platforms. CONCLUSIONS: Computerized tomographic colonography performance compared favorably with reported performance of fecal occult blood testing, flexible sigmoidoscopy, and barium enema. A prospective study evaluating the performance of computerized tomography colonography in a screening population is indicated.

Patient preferences for CT colonography, conventional colonoscopy, and bowel preparation.

OBJECTIVES: The aim of this study was to determine patient pre-examination expectations and postexamination appraisals for CT colonography, conventional colonoscopy and bowel preparation. METHODS: Prospective evaluation of 120 patients at defined risk for colorectal neoplasia was performed with CT colonography followed by colonoscopy on the same day. Subjects were stratified by age and sex (67 women and 53 men) and were randomized to receive either manual air (n = 61) or CO(2) (n = 59) insufflation during CT colonography. Patients' expectations were assessed just before the two examinations, and appraisals were assessed 2 to 3 days afterward regarding pain/discomfort, embarrassment, difficulty, overall assessment, preference for future testing, and bowel preparation. RESULTS: No significant differences were found in appraisals of manual air versus CO(2) insufflation techniques. For both CT colonography and colonoscopy, patients' appraisals after the procedure were significantly more positive than prior expectations. Patients expressed more favorable appraisals of colonoscopy for pain (p < 0.001) and embarrassment (p < 0.001), with most responses being "none" to "a little" for both examinations. Overall appraisals of the tests were favorable and similar between CT and colonoscopy: patients mainly expressed "not unpleasant" to "a little unpleasant" (95%, 114/120 for both examinations). Overall, appraisal of the bowel preparation was the most negative. Preferences for future testing were more favorable toward CT: of the patients, 58% (69/120) preferred CT, 14% (17/120) preferred colonoscopy, and 28% (34/120) had no preference. CONCLUSIONS: Overall appraisals were similar and positive for both CT colonography and colonoscopy, with less favorable appraisals of the bowel preparation. Most patients stated that they would prefer CT for future evaluation.

Detection of primary hepatic malignancy in liver transplant candidates: prospective comparison of CT, MR imaging, US, and PET.

PURPOSE: To determine and compare the diagnostic performance of computed tomography (CT), magnetic resonance (MR) imaging, ultrasonography (US), and positron emission tomography (PET) in the detection of hepatocellular carcinoma (HCC) or cholangiocarcinoma in liver transplant candidates and to determine interobserver variability between the readers. MATERIALS AND METHODS: Twenty-five patients were examined prospectively with CT, MR imaging, US, and PET. Each test result was interpreted independently by two radiologists. Explanted liver specimens were examined histologically to determine presence and type of lesion. Results were analyzed on a patient-by-patient basis with marginal homogeneity and effect likelihood ratio tests. RESULTS: HCC was diagnosed in nine patients. US diagnostic performance was superior to that of CT and MR imaging on a patient-by-patient basis. Sensitivities were higher for US (0.89 for both US readers) than they were for CT (0.67 and 0.56 for readers 1 and 2, respectively), MR imaging (0.56 and 0.50 for readers 1 and 2, respectively), and PET (0 for both readers). None of the differences (within test) between readers were significant (P >or=.32). Ratings by US and MR observers and one CT observer were significantly associated with truth (P

CT colonography: multiobserver diagnostic performance.

PURPOSE: To prospectively evaluate multiobserver diagnostic performance and reader agreement for colorectal polyp detection in a well-characterized cohort of patients with increased number of polyps, compared with an average-risk patient, with colonoscopy as the reference standard. MATERIALS AND METHODS: A cohort of 70 patients suspected of having polyps was examined with spiral computed tomographic (CT) colonography, with colonoscopy performed the same day. After air insufflation per rectum, supine and prone images were obtained with single-detector row CT (5-mm collimation, 8-mm table increment, 2-mm reconstruction interval). Images were analyzed independently by four experienced abdominal radiologists using two-dimensional multiplanar reformation followed by selective use of three-dimensional endoscopic volume-rendered images. Data were analyzed both per polyp and per patient. RESULTS: Analysis per polyp demonstrated a pooled sensitivity of 0.68 for lesions 10 mm or larger (n = 40), with 75% agreement among the four readers. Analysis per patient demonstrated improved detection and agreement, with a pooled sensitivity of 0.88 for patients with polyps or cancers 10 mm or larger (n = 28), with 94% agreement. When sensitivity and receiver operating characteristic analyses were analyzed per polyp size threshold, results among readers converged and peaked at polyp diameters of approximately 10 mm. CONCLUSION: In this patient cohort, diagnostic performance and interobserver agreement with single-detector row CT colonography was sufficient for detection of patients with lesions 10 mm or larger, with more variable results for smaller polyps.