Sensitivity and specificity of CT colonography for the detection of colonic neoplasia after positive faecal occult blood testing: systematic review and meta-analysis

Abstract

Sensitivity and specificity of CT colonography for the detection of colonic neoplasia after positive faecal occult blood testing: Systematic review and meta-analysis. European Radiology, 24 (5) 1049 -1058. 10.1007/s00330-014-3106-0 Article Sensitivity and specificity of CTC for the detection of colonic neoplasia after positive fecal occult blood testing: Systematic review and meta-analysis Abstract Objective: CT colonography (CTC) is recommended after positive fecal occult blood testing (FOBt) when colonoscopy is incomplete or infeasible. We aimed to estimate the sensitivity and specificity of CTC for colorectal cancer and adenomatous polyps following positive FOBt via systematic review. Methods:The MEDLINE, EMBASE, AMED and Cochrane Library databases were searched for CTC studies reporting sensitivity and specificity for colorectal cancer and adenomatous polyps. Included subjects had tested FOBt-positive by guaiac or immunochemical methods. Per-patient detection rates were summarized via forest plots. Meta-analysis of sensitivity and specificity was conducted using a bivariate random effects model and the average operating point calculated.Results: Of 538 articles considered, 5 met inclusion criteria, describing results from 622 patients. Research study quality was good. CTC had a high per-patient average sensitivity of 88.8% (95%CI 83.6 to 92.5%) for ≥6mm adenomas or colorectal cancer, with low betweenstudy heterogeneity. Specificity was both more heterogeneous and lower, at an average of 75.4% (95%CI 58.6 to 86.8%). Conclusion:Few studies have investigated CTC in FOBt-positive individuals. CTC is sensitive at a ≥6mm threshold but specificity is lower and variable. Despite the limited data, these results suggest CTC may adequately substitute for colonoscopy when the latter is undesirable.Keywords CT colonography, Colorectal Neoplasms, Screening, Occult blood, Review, Systematic Key points Faecal occult blood testing is the commonest mass-screening test for colorectal cancer.  Few studies specifically evaluate CT colonography after positive faecal occult blood testing.  CTC is approximately 89% sensitive for ≥6mm adenomas/cancer in this setting.  Specificity is lower, at approximately 75%, and more variable.  CT colonography is a good alternative when colonoscopy is undesirable.Abbreviations CAD = computer assisted detection CTC = computed tomographic colonography CRC = colorectal cancer gFOBt = guaiac faecal occult blood test 2 FIT = faecal immunochemical test NPV = negative predictive value PPV = positive predictive value QUADAS-2 = quality assessment of diagnostic accuracy studies, second revision

Epidemiology and screening: what's new?

“…A recent meta-analysis showed that CT colonography is adequately sensitive for lesions at a ≥ 6 mm threshold (sensitivity: 89%; 95% CI 84-93%) but specificity is far lower (specificity: 75%, 95% CI 59-87%) and variable across the studies. TC identifies significantly more advanced neoplasia per 100 participants than did CT colonography but the diagnostic yield for advanced neoplasia per 100 invitees was similar for both strategies [24]. Despite these limitations CT colonography may adequately substitute for TC when the latter is strongly undesirable [25].…”

S3-Leitlinie – Kolorektales Karzinom

“…Sensitivität und Spezifität der CT-Kolonografie sind in den letzten Jahren seit Erstellung der letzten Leitlinie angestiegen. In Übersichten der letzten Jahre lag die CT-Kolonografie entweder um 10 -20 % zurück (größen-abhängig) für alle Neoplasien im Screening-Setting [173], erreichte eine gute (88 %) Treffsicherheit für Adenome > 5 mm bei Stuhltest-positiven Screening-Kandidaten bei allerdings nur 75 % Spezifität [435], und zeigte eine sehr hohe Treffsicherheit für Karzinome in einer radiologischen Übersicht bei allen Indikationen [412]. Was die Patientenpräferenz für CT vs. Koloskopie betrifft, hängen die Ergebnisse offenbar vorwiegend vom Journal der Veröffentlichung (Radiologie vs. Gastroenterologie/Innere) und vom Ausmaß der Darmvorbereitung beim CT ab [436].…”

Recommendations on fecal immunochemical testing to screen for colorectal neoplasia: a consensus statement by the US Multi-Society Task Force on colorectal cancer

“…89 Computerized tomographic colonography and colon capsule endoscopy (CCE) are 2 other structural tests that have been evaluated in patients with a positive stool test. 90,91 A meta-analysis summarized 5 studies in which individuals were either gFOBT or FIT positive and underwent computerized tomographic colonography and a verification test (generally colonoscopy). Although sensitivity for adenomas 6 mm or larger was reasonably good (average, 89%; 95% CI, 84%-92%), specificity suffered (average, 75.4%; 95% CI, 59%-87%).…”