Prevalence and characteristics of colonic polyps and adenomas in 2654 colonoscopies in Saudi Arabia

Abstract

Background/aims: Colorectal cancer (CRC) is the second most common malignancy in the Saudi population, with an increasing incidence over the past 20 years. We aim to determine the baseline polyp as well as adenoma prevalence in a large cohort of patients and to find the possible age in which, if deemed appropriate, a CRC screening program should be initiated.

Patients and methods: A retrospective cohort study was conducted using an endoscopic reporting database of individuals seen at a major tertiary care university hospital (King Khalid University Hospital) in Riyadh, Saudi Arabia. Consecutive Saudi patients who underwent a colonoscopy between August 2007 and April 2012 were included. Patients were excluded if the indication for the colonoscopy was colon cancer, colonic resection, active colitis, active diverticulitis, inflammatory bowel disease, or if the patient was referred for polypectomy.

Results: 2654 colonoscopies were included in the study. The mean age of the study population was 50.5 years [standard deviation (SD) 15.9] and females represented 57.7%. The polyp detection rate in completed colonoscopies was 20.8% (95% CI: 19.2-22.5). Adenomas were found in 8.1% (95% CI: 7.1-9.1), while advanced adenomas were found in only 0.5% (95% CI: 0.2-0.7). Adenomas were found in the left side of the colon in 33.9%, followed by the rectum in 14.6%, ascending colon and cecum in 14.2%, transverse colon in 8.7%, and in multiple locations in 28.7%. Those with a prior history of polyps or CRC were more likely to have an adenoma at colonoscopy than those who did not (14.3% vs. 6.6%; P < 0.01). The adenoma prevalence varied between age groups and ranged from 6.2% to 13.6% with a higher proportion in older individuals; this trend was seen both in males (6.0-14.5%) and females (6.4-14.6%) as well as in those who had screening colonoscopies (6.3-18.4%). No age could be found at which a CRC screening program would be appropriate to initiate.

Conclusion: The prevalence of polyps and adenomas in this cohort is less than that reported in the Western populations. But as this cohort included younger and symptomatic patients with only a small proportion undergoing screening, further studies in an asymptomatic population are needed.

Figure 1

The age distribution of those who had polyps detected at colonoscopy

Figure 2

Receiver operating characteristics (ROC) curve for the optimum age to perform colonoscopy for the detection of adenomas. The area under the ROC curve was 0.59