Risk factors for malignancy and serious infection in patients with inflammatory bowel disease: a retrospective analysis

Abstract

Background: Patients with inflammatory bowel disease (IBD) are at increased risk of malignancy and infection compared to the general population.

Aims: We aim to identify risk factors for malignancy or serious infection in our IBD cohort.

Methods: Patients with IBD from a single tertiary referral centre were included. Demographic and clinical details, including immunosuppressant exposure, were collected and medical records retrospectively screened for adverse events, including malignancy or infection requiring hospitalisation. Logistic regression was used to evaluate risk factors for adverse events.

Results: Five hundred and forty-nine patients with IBD (340 Crohn disease (CD) and 209 ulcerative colitis (UC)) were studied. Forty-eight malignancies, including 39 (81.3%) non-melanoma skin cancers, 3 (6.3%) haematologic malignancies and 6 (15.4%) solid-organ malignancies, were identified, and 92 cases of serious infection were detected. IBD duration (odds ratio (OR) = 1.08; 95% confidence interval (CI) = 1.03-1.13) and ileocolonic CD (OR = 4.96; 95% CI = 1.13-21.71) were associated with increased odds of overall cancer. Compared with patients not previously exposed to the given class of immunosuppression assessed, the development of overall malignancy was not higher with thiopurine exposure (OR = 1.00; 95% CI = 0.50-2.24) or anti-tumour necrosis factor-alpha (TNF-α) exposure (OR = 0.78; 95% CI = 0.37-1.64). Similarly, compared with patients not exposed, infection risk was not affected by thiopurine (OR = 0.74; 95% CI = 0.46-1.20) or anti-TNF exposure (OR = 0.60; 95% CI = 0.38-0.95).

Conclusions: Factors including ileocolonic CD and increasing IBD duration were associated with higher malignancy risk in this cohort. Compared with non-exposure, patients exposed to thiopurines were not at increased risk of malignancy or serious infection. Similarly, patients exposed to anti-TNF treatment did not experience increased rates of malignancy or serious infection compared to patients not exposed to this treatment.

Keywords: Crohn disease; immunosuppression; infection; malignancy; ulcerative colitis.