Author(s): Gabriel Capellá 
[box 1]Imperiale TF et al . (2004) Fecal DNA versus fecal occult blood for colorectal-cancer screening in an average-risk population. N Engl J Med 351: 2704-2714
Fecal occult-blood testing (FOBT) is a noninvasive, effective means of screening for colorectal cancer (CRC). The SENSITIVITY of this technique is suboptimal, however, and identification of a simple, noninvasive test for detection of tumor products could improve screening in patients not able to undergo colonoscopy.
To compare the effectiveness of a fecal-based, multitarget DNA panel test with the Hemoccult II[R] fecal occult-blood test, for detection of CRC in average-risk, asymptomatic adults.
Design and Intervention
The study was conducted at 81 private practice and university-based sites between August 2001 and March 2003. All participants were at least 50 years old. Exclusion criteria included iron-deficiency anemia, coexisting visceral cancer, recent gastrointestinal bleeding, change in bowel habits or abdominal pain, previous CRC or polyps or colon resection; colonoscopy, sigmoidoscopy or double-contrast barium enema within the previous 10 years, or positive FOBT within the previous 6 months. Individuals provided a fecal sample for DNA testing and then completed three Hemoccult II[R] cards for FOBT before screening colonoscopy. DNA analysis was performed on stool samples from all evaluable patients with invasive cancer or advanced adenoma, and subgroups of subjects with minor polyps (n = 600) and no polyps (n = 1,400). All analysis was blinded to fecal sample DNA test results and screening colonoscopy.
Any lesion containing high-grade dysplasia, polyp-containing villous architecture, or tubular adenoma at least 1 cm in diameter was defined as advanced adenoma. Minor polyps included tubular adenomas less than 1 cm in diameter and hyperplastic polyps.
Of 4404 evaluable subjects, invasive adenocarcinoma was identified in 31 (prevalence 0.7%). Fecal DNA testing detected 16 of 31 invasive cancers (TNM STAGE I, II or III), with a sensitivity of 51.6%. FOBT detected 4 of 31 cancers, with a sensitivity of 12.9%. Subsequent analysis in patients with node-negative...