Objective: To determine the yield of colorectal cancer at routine colonic evaluation after radiologically proven acute diverticulitis.
Background: Acute diverticulitis accounts for 152,000 hospitalizations in the United States alone. Current guidelines recommend routine colonic evaluation after acute diverticulitis to confirm the diagnosis and exclude malignancy. However, research suggests that the yield of colorectal cancer after computed tomography-proven uncomplicated diverticulitis may be low. In the era of widespread computed tomographic scanning for diverticulitis, routine colonic evaluation after diverticulitis may represent a nonessential burden on health care resources.
Methods: The PubMed (MEDLINE), EMBASE, BIREME, CINAHL, and the Cochrane Library databases were searched. Original studies of colonic evaluation after proven acute diverticulitis were included. Meta-analysis of data from included studies was performed using a DerSimonian Laird random effect proportion analysis.
Results: Eleven studies from 7 countries were included in the analysis. Out of a pooled population of 1970 patients, cancer was found in 22. The pooled proportional estimate of malignancy was 1.6% (95% confidence interval [CI], 0.9%-2.8%). Of the 1497 patients with uncomplicated diverticulitis, cancer was found in 5 (proportional estimate of risk 0.7%; CI, 0.3%-1.4%). Of the 79 patients with complicated disease, cancer was found in 6 (proportion estimate of risk 10.8%; CI, 5.2%-21.0%).
Conclusions: The risk of malignancy after a radiologically proven episode of acute uncomplicated diverticulitis is low. In the absence of other indications, routine colonoscopy may not be necessary. Patients with complicated diverticulitis still have a significant risk of colorectal cancer at subsequent colonic evaluation.