Can Colonoscopy Performed for Reason Other Than Screening Replace Screening Colonoscopy for Colorectal Carcinoma Screening

Abstract

Purpose: Colonoscopy is performed as a screening procedure for colorectal cancer (CRC). During this procedure, polyps, which could be premalignant lesions, are removed thereby reducing the risk of development of CRC. Gastroenterologists also perform colonoscopy for other indications such as bleeding and anemia. The aim of this study is to determine if there is a difference in the rate of polyp detection between screening and other indications for colonoscopy. Methods: All colonoscopies performed at Henry Ford Hospital for a period of one year between 03/01/1999 to 04/01/2000 were reviewed. The indication for colonoscopy and findings were noted in all cases. The primary end point was the detection of any polyp based on size and the secondary end point was the detection of an adenomatous polyp. The chi-square test was used to calculate the percent differences in polyp detection between groups based on the indication for colonoscopy.Table: Table 1. Indication of colonoscopy and rate of polyp detectionResults: There were a total of 2096 colonoscopies performed on 1547 patients. Of these patients, 48% were male, 67% were African American and 30% were Caucasian. Of the 2096 colonoscopies performed, polyps were detected in 980 (46.7%), and of these 675 (32%) were adenomatous polyps. Major indications for colonoscopy were screening (12%), surveillance (18%), abnormal radiology (4%), bleeding (30%), positive fecal occult blood test (17%), iron deficiency anemia (11%) and bowel habit change (7%). Rate of detection of any polyp, <10 mm polyp and adenomatous polyp are presented in Table-1. Rate of polyp detection (for all three groups) in screening and surveillance colonoscopy were higher in comparison with other indications and were statistically significant (except abnormal radiology). Conclusion: The rate of detection of all polyps, including polyps <10 mm and adenomatous polyps, was significantly higher in screening and surveillance colonoscopy than other indications for colonoscopy. Any program using colonoscopy to screen for colo-rectal cancer that is based on bleeding or anemia has rates of polyp detection inferior to general screening and is inappropriate.