Is the prevalence of colonic neuroendocrine tumors increased in patients with inflammatory bowel disease?

Abstract

Inflammatory bowel disease (IBD) patients may bear an increased neuroendocrine tumor (NET) risk. These tumors are mostly reported as coincidental findings during surgery. We aimed to determine the prevalence of colonic NET in a Dutch nationwide IBD cohort and calculate the prevalence rate ratios (PRR) compared with the general Dutch population. Our second aim was to investigate whether a high bowel surgery rate in IBD could result in a high PRR for NET. The Dutch Pathology Registry (PALGA) was searched to identify all IBD patients with colonic NET in The Netherlands between 1991 and 2011. We determined the prevalence and PRR of colonic NET in a 20-year period. For our second aim, we compared NET prevalence in colonic resection specimens between IBD cases and non-IBD controls (diverticulitis and ischemia). We identified 51 IBD patients who developed colonic NET resulting in a prevalence of 60.4-89.3 per 100,000 patients in a 20-year period with a PRR of 2.8-4.1. However, adjusted for resection type, sex and age, a higher NET prevalence was shown in diverticulitis (OR 5.52,) and ischemia (OR 1.97, 95% CI 1.09-3.58) compared with IBD. Our key finding is that NET are more prevalent in IBD patients compared with the general population (PRR 2.8-4.1). This might be attributed to a high rate of incidental NET as IBD patients frequently undergo intestinal surgery. A lower adjusted NET prevalence in colonic resection specimens for IBD compared to ischemia and diverticulitis supports this hypothesis.Colorectal cancer (CRC) risk is increased in patients with inflammatory bowel disease (IBD). 1,2 As IBD duration, extent and severity of disease drive CRC risk, it is assumed that chronic intestinal inflammation is an important contributing factor. 3 In addition to an increased CRC risk, IBD patients also carry a risk to develop other types of neoplasia such as neuroendocrine tumors (NET). Several authors have reported cases of both IBD and NET resulting in the hypothesis that inflammation may cause hyperstimulation of enteroendocrine cells leading to hyperplasia and neoplasia. [4][5][6] However, convincing epidemiological evidence of an association between IBD and NET is lacking so far.NET risk in IBD patients has been poorly investigated and reported results are variable. Two studies including, respectively, 590 and 111 IBD patients, found an increased risk of NET development compared to the background population. 5,7 By contrast another study among 705 IBD cases did not detect an increased prevalence. 6 However, all these data were collected from single tertiary referral centers introducing referral and selection bias and as such may not be representative for the IBD population at large. Furthermore, high surgery rates in IBD [25-30% in ulcerative colitis (UC) and 70-80% in Crohn's disease (CD)] may lead to high NET risks, as these tumors are mostly detected by coincidence during surgery. 8,9 Therefore, the comparison of NET risks across studies is difficult given the variable rates of bowel surgery in control groups in the ...

From microbiota toward gastro-enteropancreatic neuroendocrine neoplasms: Are we on the highway to hell?

“…In contrast, a recent Dutch nationwide study reported in the entire cohort of IBD patients from national pathological database 51 patients with concomitant IBD and colonic NENs with an estimated prevalence rate ratios between 2.8 and 4.1. These values were lower than ones from colonic resection specimens for diverticulitis and ischemia adjusted for resection type, sex and age, suggesting an incidental finding because of frequent colonic resection [173].…”

Gastroenteropancreatic Neuroendocrine Neoplasms in Patients with Inflammatory Bowel Disease: An ECCO CONFER Multicentre Case Series

“…were reported from academic centres. Of these, 51 cases were previously reported within case-series [6] and case-report [11].…”

“…To date, GEP-NENs have rarely been reported in association with IBD. Data are limited to case-reports and retrospective cohort studies, mainly based on histological registries and lack correlation with IBD's clinical characteristics and course [6][7][8][9][10][11]. We aimed to describe a series of patients with IBD and GEP-NENs, and to delineate the association between IBD, GEP-NEN features, and patient outcomes.…”

Epithelioid Hemangioendothelioma of the Bowel in Crohn’s Disease: The First Reported Case

“…Patients with long-standing IBD are predisposed to developing gastrointestinal malignancies, most frequently adenocarcinoma, neuroendocrine carcinoma, and non-Hodgkin lymphoma. [11][12][13] Furthermore, some studies suggest that the use of immunosuppressive drugs in patients with IBD may pose an increased risk for developing neoplasms, most commonly lymphomas. 14,15 A significant proportion of these secondary tumors are not detected prior to bowel resection, and this phenomenon emphasizes the need to carefully dissect and sample these specimens.…”