DIVERT-Ca: unveiling the hidden link between acute diverticulitis and colorectal cancer risk-multicentre retrospective study

Abstract

Introduction: Colorectal cancer (CRC) is the third most common cancer worldwide, accounting for approximately 10% of all malignancies. Emerging trends of association with risk factors such as diverticulitis highlight the need for updated screening and follow-up protocols. We aimed to examine risk factors associated with the development of CRC within 12 months following an episode of acute diverticulitis, and identify areas to streamline follow-up.

Methods: We performed a retrospective multicentre study of adult patients admitted in 2022 with computed tomography (CT) confirmed acute diverticulitis across four large NHS Trusts in the UK. Patient demographics, comorbidities, clinical presentation, vital signs, laboratory results, details of in-patient stay, and follow-up investigations were collected and analysed. Our primary outcome was the incidence of CRC within 12 months of index presentation with acute diverticulitis. Analysed secondary outcomes were potential patient risk factors associated with a diagnosis of CRC and follow-up protocols. All statistical analysis was performed using R (version 4.4) and P-values of < 0.05 were considered statistically significant.

Results: A total of 542 patients with acute diverticulitis over the study period were included. The median age of our cohort was 62 (51-73) years, and 204 (37.6%) were male. Ten (1.8%) patients were diagnosed with CRC within the 12-month period. Hinchey grade Ib was significantly associated with CRC (OR 4.51, P = 0.028). Colonoscopic follow-up requests were associated with age between 40 and 60 years, mild white cell count (WCC) elevation, and a hospital stay of 3-7 days. Male gender, age between 18 and 40 years, and elevated C-reactive protein (CRP) were all strongly associated with CRC but not statistically significant. Follow-up was inconsistent with 53.7% of the cohort having luminal investigations.

Conclusion: The incidence of CRC was in-keeping with published literature. Hinchey grade 1b was significantly associated with a subsequent CRC diagnosis. These findings emphasise the need for specialised radiological review of CT scans to detect underlying malignancy. Moreover, standardised follow-up protocols following an episode of acute diverticulitis are needed to avoid missing malignant lesions.