Barium enema is widely available for diagnosis of colorectal cancer despite concerns about its accuracy and acceptability. Computed tomographic colonography ( CTC ) might be a more sensitive and acceptable alternative.
Researchers have compared CTC and Barium enema for diagnosis of colorectal cancer or large polyps in symptomatic patients in clinical practice.
The multicentre randomised trial recruited patients with symptoms suggestive of colorectal cancer from 21 UK hospitals.
Eligible patients were aged 55 years or older and regarded by their referring clinician as suitable for radiological investigation of the colon.
Patients were randomly assigned ( 2:1 ) to Barium enema or CTC by computer-generated random numbers, in blocks of six, stratified by trial centre and sex.
Researchers analysed the primary outcome ( diagnosis of colorectal cancer or large [ greater than or equal to 10 mm ] polyps ) by intention-to-treat.
3838 patients were randomly assigned to receive either Barium enema ( n=2553 ) or computed tomographic colonography ( n=1285 ). 34 patients withdrew consent, leaving for analysis 2527 assigned to Barium enema and 1277 assigned to computed tomographic colonography.
The detection rate of colorectal cancer or large polyps was significantly higher in patients assigned to computed tomographic colonography than in those assigned to Barium enema ( 93 [ 7.3% ] of 1277 vs 141 [ 5.6% ] of 2527, relative risk, RR=1.31; p=0.0390 ).
Computed tomographic colonography missed three of 45 colorectal cancers and Barium enema missed 12 of 85. The rate of additional colonic investigation was higher after computed tomographic colonography than after Barium enema ( 283 [ 23.5% ] of 1206 CTC patients had additional investigation vs 422 [ 18•3% ] of 2300 Barium enema patients; p=0.0003 ), due mainly to a higher polyp detection rate.
Serious adverse events were rare.
Computed tomographic colonography is a more sensitive test than Barium enema. The results suggest that computed tomographic colonography should be the preferred radiological test for patients with symptoms suggestive of colorectal cancer. ( Xagena )
Halligan S et al, The Lancet 2013; 381: 1185-1193