Systematic Review and Meta-analysis on Colorectal Cancer Findings on Colonic Evaluation After CT-Confirmed Acute Diverticulitis.

BACKGROUND: CT findings of acute diverticulitis can overlap with features of malignancy, and current guidelines recommend colonic evaluation after acute diverticulitis. However, the benefits of routine colonic evaluation have been questioned. OBJECTIVE: We review 30 studies, composed of 29,348 subjects, to evaluate the role of routine colonic evaluation after CT-proven acute diverticulitis. DATA SOURCES: Medline, EMBASE, and the Cochrane Library were searched for articles published up to July 2018 to identify all relevant articles. STUDY SELECTION: A combination of both Medical Subject Headings and non-Medical Subject Headings key terms using Boolean operators were used on Medline, including colonic neoplasms, colorectal cancer, colon cancer, colonic cancer, colonoscopy, and diverticulitis. Any randomized or nonrandomized, English-language article that specifically analyzed incidence of colorectal cancer after performing colonoscopy in patients with previous diverticulitis was included. MAIN OUTCOME MEASURES: The desired outcome was to evaluate for incidence of colonic malignancy in cases of acute colonic diverticulitis. Subgroup analyses for incidence of malignancy in uncomplicated and complicated diverticulitis, and Asian population studies were also performed. RESULTS: Findings of colonic malignancy occurred in 1.67% (95% CI, 1.24-2.14) of patients with CT-diagnosed diverticulitis. The risk of malignancy in cases with uncomplicated diverticulitis was 1.22% (95% CI, 0.63-1.97) as compared with 6.14% (95% CI, 3.20-9.82) in cases with complicated diverticulitis, with a relative risk of 5.033 (95% CI, 3.194-7.930; p < 0.001). LIMITATIONS: Significant variability in design and methodology of the individual studies contributed to the heterogeneity of this study, but these were addressed by using the random-effects model analysis. CONCLUSIONS: Colonic evaluation is worth considering for patients with diverticulitis because of the small but serious risk of underlying malignancy. The risk of malignancy is higher for patients of advanced age and with complicated diverticulitis.