Colorectal Cancers Found After a Complete Colonoscopy

Adenoma Detection Rate and Risk of Colorectal Cancer and Death

“…Previous studies have focused primarily on cancers occurring within 3 to 5 years after the colonoscopic examination; rapidly progressing adenomas or cancers that were present but not detected at the time of colonoscopy would presumably account for these interval cancers. 15,21,29,30,[33][34][35][36][37][38][39][40][41] The number of cancers detected in this study is similar to or lower than the numbers observed in other studies (which often evaluated cancers over a shorter period). 29,30 Interval cancers accounted for only 8.2% of all colorectal cancers detected in our study cohort, and the absolute risk of an interval cancer was relatively low (9.8 interval cancers per 10,000 person-years of follow-up in quintile 1 of adenoma detection rates and 4.8 interval cancers per 10,000 person-years of follow-up in quintile 5).…”

Colonoscopy Quality Assessment

“…Several studies evaluating interval CRCs found that these cancers can be attributed to incomplete polypectomy in about 10% to 30% of cases 13,20,22,64,65 . Since ADR is essentially geared at assessing detection and not resection, the inadequate quality in these cases would not be reflected by measuring the ADR.…”

“…Interval CRCs (or post-colonoscopy CRCs) account for 3.4% to 9% of all cases of CRCs and are primarily encountered in the right colon [10][11][12][13][14][15] .…”

Screening and Surveillance for the Early Detection of Colorectal Cancer and Adenomatous Polyps, 2008: A Joint Guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology

“…Of note, the pooled CTC sensitivity for invasive CRC was 96%, 168 comparable with the reported sensitivity for OC. 119,121 There also are a number of CTC trials currently in progress within the United States and Europe. Initial results from smaller screening trials utilizing 3D polyp detection by Cash et al 170 and Graser et al 171 have shown CTC performance characteristics similar to that of Pickhardt et al, providing at least a measure of independent validation for this screening technique.…”

“…117 Polypectomy is sometimes ineffective in eradicating polyps, a factor that has been implicated as the cause of up to 25% of interval cancers. 118,119 Finally,colonoscopy is not an infallible "gold standard." Controlled studies have shown the colonoscopy miss rate for large adenomas (ϭ10 mm) to be 6% to 12%.…”