Risk of Colorectal Cancer in Incarcerated Patients With Inflammatory Bowel Disease in the United States: A Population-Based Study

Introduction: Patients with inflammatory bowel disease (IBD) are at significantly increased risk of developing colorectal cancer (CRC). Despite the decline in incidence of IBD-associated CRC due to improvements in CRC surveillance programs and therapeutic advancements, prior studies show there remain significant disparities amongst vulnerable populations, such as incarcerated patients. This study is the first to assess the risk of CRC in incarcerated patients with IBD using a large population-based database. Methods: We used a large federated de-identified health research network, TriNetX, with data sourced from 80 healthcare organizations (HCO) within the United States. We identified patients with a diagnosis of IBD based on International Classification of Diseases (ICD)-10 codes between 2007-2023, and stratified based on a record of imprisonment. Available clinical data, including demographics, comorbid conditions, procedure history, medication use, and the outcome of CRC were collected. We compared prevalence and incidence of CRC after IBD diagnosis in incarcerated patients with IBD to a control cohort without a history of incarceration. Outcome risk was assessed using odds ratios and 95% confidence intervals. Results: We found a total of 512,680 patients with IBD. Among them, 3,660 IBD patients were incarcerated (IC) and the remaining 509,017 individuals were non-incarcerated (non-IC). Three hundred and forty-nine IBD patients in the IC group developed CRC after IBD diagnosis, whereas 13,535 developed CRC in the non-IC group. Compared to their non-IC counterparts, IC individuals with IBD were more likely to be male (61.8 % vs 44.6 %, P< 0.0001), non-Hispanic/Latino (85.3% vs 10.9%, P< 0.0001), and had higher prevalence of risk factors for CRC (P< 0.0001) (Table 1). Surrogates of severe IBD phenotypes such as peri-anal and fistulizing disease were also significantly higher in the IC group compared to the non-IC group (P< 0.001). For the primary outcome of CRC risk in patients with IBD, the IC group had a significantly higher prevalence (9.6% vs 5.7%, OR=1.75; 95% CI: 1.46-2.09, P< 0.001) and incidence (4.5% vs 2.4%, OR=1.88; 95% CI: 1.43-2.46, P< 0.001) compared to the non-IC group (Figure 1). Conclusion: To our knowledge, this is the first large retrospective cohort study to demonstrate increased CRC incidence in IBD patients who have been incarcerated. This is likely due to poor health maintenance in these individuals and the disproportionately reduced access to health care services during and subsequent to incarceration.Figure 1.: Prevalence and Incidence of Colorectal Cancer (CRC) in Patients with Inflammatory Bowel Disease with a Record of Incarceration (IBD IC) Versus Those Without (IBD Non-IC). Table 1. - Baseline Characteristics of Patients With Some Form of Inflammatory Bowel Disease (IBD, Crohn’s disease, or Ulcerative colitis), Between Those with a Record of Incarceration (IC), and Those Without (Non-IC) Before and After Propensity Score Matching Before Matching After Matching IBD IC (N =3663) IBD Non-IC (N=509017) P-Value IBD IC (N=3660) IBD Non-IC (N=3660) P-Value Age at Index, years (mean ± SD) 46.67 ± 18.05 46.29 ± 20.27 0.2522 46.67 ± 18.06 47.09 ± 18.33 0.3238 Gender, n (%) Male 2263 (61.8%) 226942 (44.6%) < 0.0001 2260 (61.7%) 2260 (61.7%) 1.0000 Female 1400 (38.2%) 281948 (55.4%) < 0.0001 1400 (38.3%) 1400 (38.3%) 1.0000 Race, n (%) White 2753 (75.2%) 376210 (73.9%) 0.0866 2751 (75.2%) 2751 (75.2%) 1.0000 Black or African American 693 (18.9%) 44341 (8.7%) < 0.0001 692 (18.9%) 692 (18.9%) 1.0000 American Indian or Alaska Native 23 (0.6%) 1354 (0.3%) < 0.0001 23 (0.6%) 26 (0.7%) 0.6672 Asian 18 (0.5%) 8454 (1.7%) < 0.0001 18 (0.5%) 20 (0.5%) 0.7450 Native Hawaiian or Other Pacific Islander 10 (0.3%) 405 (0.1%) < 0.0001 10 (0.3%) 0 (0.0%) 0.0016 Other Race 175 (4.8%) 78253 (15.4%) < 0.0001 175 (4.8%) 171 (4.7%) 0.8256 Ethnicity, n (%) Not Hispanic or Latino 3125 (85.3%) 342262 (67.2%) < 0.0001 3123 (85.3%) 3129 (85.5%) 0.8425 Hispanic or Latino 399 (10.9%) 23223 (4.6%) < 0.0001 398 (10.9%) 392 (10.7%) 0.8212 Unknown Ethnicity 139 (3.8%) 143532 (28.2%) < 0.0001 139 (3.8%) 139 (3.8%) 1.0000 Comorbidities/Lifestyle-Associated Risk Factors, n (%) Nicotine dependence 1760 (48.0%) 36230 (7.1%) < 0.0001 1757 (48.0%) 1764 (48.2%) 0.8699 Diabetes mellitus 1531 (41.8%) 45044 (8.8%) < 0.0001 1528 (41.7%) 1525 (41.7%) 0.9433 Overweight and obesity 1294 (35.3%) 40747 (8.0%) < 0.0001 1291 (35.3%) 1297 (35.4%) 0.8834 Family history of malignant neoplasm of digestive organs 642 (17.5%) 10131 (2.0%) < 0.0001 641 (17.5%) 642 (17.5%) 0.9755 Primary sclerosing cholangitis 35 (1.0%) 1003 (0.2%) < 0.0001 33 (0.9%) 24 (0.7%) 0.2314 Complications, n (%) Anal fissure, unspecified 126 (3.4%) 3687 (0.7%) < 0.0001 126 (3.4%) 60 (1.6%) < 0.0001 Rectal abscess 117 (3.2%) 2810 (0.6%) < 0.0001 117 (3.2%) 64 (1.7%) 0.0001 Anal abscess 88 (2.4%) 2607 (0.5%) < 0.0001 88 (2.4%) 47 (1.3%) 0.0004 Anorectal fistula 68 (1.9%) 1749 (0.3%) < 0.0001 68 (1.9%) 25 (0.7%) < 0.0001 Crohn's disease of small intestine with fistula 40 (1.1%) 0 (0.0%) < 0.0001 40 (1.1%) 0 (0.0%) < 0.0001 Other and unspecified intestinal obstruction 833 (22.7%) 10257 (2.0%) < 0.0001 832 (22.7%) 238 (6.5%) < 0.0001 Colectomy, partial 64 (1.7%) 1056 (0.2%) < 0.0001 64 (1.7%) 24 (0.7%) < 0.0001 Colectomy, total, abdominal, without proctectomy 31 (0.8%) 166 (0.0%) < 0.0001 31 (0.8%) 10 (0.3%) 0.0010 Colectomy, total, abdominal, with proctectomy 10 (0.3%) 87 (0.0%) < 0.0001 10 (0.3%) 10 (0.3%) 1.0000 Proctectomy, partial, with rectal mucosectomy, ileoanal anastomosis 10 (0.3%) 16 (0.0%) < 0.0001 10 (0.3%) 0 (0.0%) 0.0016 IBD therapies, n (%) 5-ASA mesalamine 511 (14.0%) 38684 (7.6%) < 0.0001 510 (13.9%) 258 (7.0%) < 0.0001 sulfasalazine 193 (5.3%) 6380 (1.3%) < 0.0001 193 (5.3%) 44 (1.2%) < 0.0001 balsalazide 34 (0.9%) 3191 (0.6%) 0.0215 34 (0.9%) 20 (0.5%) 0.0558 Immunomodulators 511 (13.9%) 16775 (3.3%) < 0.0001 511 (13.9%) 167 (4.6%) < 0.0001 Small-molecule drugs (SMDs) 20 (0.6%) 57 (0%) < 0.0001 20 (0.6%) 0 (0.0%) 0.0016 Biologics Adalimumab 222 (6.1%) 7675 (1.5%) < 0.0001 221 (6.0%) 69 (1.9%) < 0.0001 Infliximab 200 (5.5%) 5362 (1.1%) < 0.0001 199 (5.4%) 31 (0.8%) < 0.0001 Vedolizumab 54 (1.5%) 1072 (0.2%) < 0.0001 54 (1.5%) 10 (0.3%) < 0.0001 Ustekinumab 36 (1.0%) 1501 (0.3%) < 0.0001 36 (1.0%) 11 (0.3%) 0.0003 Certolizumab pegol 35 (1.0%) 657 (0.1%) < 0.0001 35 (1.0%) 10 (0.3%) 0.0002 Other biologics 0 (0.0%) 30 (0.0%) 0.6422 0 (0.0%) 10 (0.3%) 0.0016