"Computed tomographic colonography versus colonoscopy for investigation of patients with symptoms suggestive of colorectal cancer (SIGGAR): a multicentre randomised trial"
Lancet Feb 14 (online)
http://www.lancet.com/journals/lancet/article/PIIS0140-6736(12)62186-2/abstract
"Findings

1610 patients were randomly assigned to receive either colonoscopy (n=1072) or CTC (n=538). 30 patients withdrew consent, leaving for analysis 1047 assigned to colonoscopy and 533 assigned to CTC. 160 (30·0%) patients in the CTC group had additional colonic investigation compared with 86 (8·2%) in the colonoscopy group (relative risk 3·65, 95% CI 2·87—4·65; p<0·0001). Almost half the referrals after CTC were for small (<10 mm) polyps or clinical uncertainty, with low predictive value for large polyps or cancer. Detection rates of colorectal cancer or large polyps in the trial cohort were 11% for both procedures. CTC missed 1 of 29 colorectal cancers and colonoscopy missed none (of 55). Serious adverse events were rare.

Interpretation

Guidelines are needed to reduce the referral rate after CTC. For most patients, however, CTC provides a similarly sensitive, less invasive alternative to colonoscopy."