The value of CA125 in predicting acute complicated colonic diverticulitis

Background: CA125 is a widely used serum marker for epithelial ovarian cancer which levels may also rise in benign conditions involving peritoneal irritation. We aimed to determine if serum CA125 levels can predict disease severity in patients presenting with acute diverticulitis. Methods: We conducted a single-center prospective observational study, analyzing CA125 serum levels in patients who presented to the emergency department with computerized tomography-proven acute left-sided colonic diverticulitis. Univariate, multivariate, and receiver operating characteristic (ROC) analyses were used to correlate CA125 serum levels at time of initial presentation with the primary outcome (complicated diverticulitis) and secondary clinical outcomes (need for urgent intervention, length of hospital stay (LOS) and readmission rates). Results: One hundred and fifty-one patients were enrolled between January 2018 and July 2020 (66.9% females, median age 61 years). Twenty-five patients (16.5%) presented with complicated diverticulitis. CA125 levels were significantly higher among patients with complicated (median: 16 (7–159) u/ml) vs. uncomplicated (8 (3–39) u/ml) diverticulitis (p < 0.001) and also correlated with the Hinchey severity class (p < 0.001). Higher CA125 levels upon admission were associated with a longer LOS and a greater chance to undergo invasive procedure during the hospitalization. In patients with a measurable intra-abdominal abscess (n = 24), CA125 levels were correlated with the size of the abscess (Spearman’s r = 0.46, p = 0.02). On ROC analysis to predict complicated diverticulitis, the area under the curve (AUC) for CA125 (AUC = 0.82) was bigger than for the leukocyte count (AUC = 0.53), body temperature (AUC = 0.59), and neutrophil–lymphocyte ratio (AUC = 0.70) — all p values < 0.05. On multivariate analysis of factors available at presentation, CA125 was found to be the only independent predictor of complicated diverticulitis (OR 1.12 (95% CI 1.06–1.19), p < 0.001). Conclusions: The results from this feasibility study suggest that CA125 may accurately discriminate between simple and complicated diverticulitis, meriting further prospective investigation.