By Bruce Sylvester
SAN DIEGO -- October 29, 2009 -- Patients diagnosed with diverticulosis may not have to undergo aggressive screening to find polyps in the colon, since these patients have a significantly lower risk of developing these lesions, according to research presented here at the American College of Gastroenterology (ACG) 74th Annual Scientific Meeting.
"We found that patients with diverticulosis have a lower incidence of polyps overall, and a tendency for less-advanced polyps," explained lead author Ali Nawras, MD, Henry Ford Hospital, Detroit, Michigan, speaking here on October 27. "These results suggest that, for patients with diverticulosis, a less-aggressive surveillance regimen could be appropriate."
Dr. Nawras and colleagues sought to determine whether asymptomatic patients with diverticular disease are at higher or lower risk for developing colonic polyps. The researchers scrutinised the hospital records of 1,668 patients who had undergone full colonoscopy and had an average risk for colon cancer. The case group of 899 patients included those with diverticulosis; a control group of 769 patients did not have diverticulosis.
The incidence of polyps was much less among the diverticulosis patients (223 cases, 24% of total) than among the control subjects (336 cases, 43%) (P < .001).
"In Western countries, the prevalence of colonic polyps and diverticular disease markedly increases with age," Dr. Nawras reported. "However, there is conflicting and limited data about the coincidence of both diseases in the same individuals. Moreover, most of the studies reported before included patients that underwent diagnostic colonoscopy for a variety of symptoms."
While the results would argue for a need for less surveillance among asymptomatic patients with diverticulosis, the researchers noted that larger, prospective studies are needed to confirm their results.
The team also investigated differences in the size and pathologies of the lesions observed. Dr. Nawras said that 109 (12%) of subjects with diverticulosis were found with polyps less than 6 mm. He added that 140 (18%) patients in the control group had polyps less than 6 mm (P < .001).
Polyps 6 to 10 mm in size were located in 77 (8.5%) subjects with diverticulosis compared with 117 (15%) subjects without diverticulosis (P < .001). Among the diverticulosis patients, 36 (4%) subjects in the group were found to have polyps greater than 1 cm in size compared with 75 (9.7%) subjects without diverticulosis (P < .001).
No cancers were observed among the diverticulosis group; 7 cancers were found among the control patients.
Overall, Dr. Nawras said subjects with diverticulosis had a significantly lower rate of high-risk polyps than did control subjects -- 36 (4.1%) versus 76 or (6.8%) (P < .001).
[Presentation title: Co-incidence of Diverticulosis and Polyps in the Colon. Abstract P1044]
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