The rate and risk factors for malignancy in patients with inflammatory bowel disease in Crete: a case control study

OBJECTIVES: About 30% of the patients with inflammatory bowel disease (IBD) develop malignancies, which constitute the second cause of death, after cardiovascular diseases. This study aimed to investigate the prevalence, risk factors, and outcome of malignancies in IBD patients in Crete. METHODS: This is a retrospective study of prospective longitudinal IBD registries at the University Hospital and Venizelion General Hospital of Heraklion, Crete. IBD patients with malignancies were compared with IBD controls without malignancies [matching 1:3 according to sex, IBD diagnosis (ulcerative colitis, Crohn's disease; CD), age (±5 years)]. RESULTS: From 2.382 IBD patients, 107 (4.5%) were diagnosed with cancer during their follow-up. Among those, 49 (45.8%) were females, and 54 (50.5%) had CD. The majority were extraintestinal malignancies, while 12 (11.2%) had colorectal cancer. In the multivariate analysis, inflammatory CD phenotype (Odds ratio (OR), 0.28; 95% confidence interval (CI), 0.09-0.58) was protective, whereas colonic location (OR, 4.8; 95% CI, 1.81-12.79) remained a risk factor for malignancy. Twelve (11.2%) had a cancer recurrence, 19 (17.8%) died of cancer, whereas the initiation of biologics, immunomodulators (IMMs) or in combination after the cancer diagnosis did not have a negative impact either on the survival or on the possibility of recurrence. CONCLUSION: The rate of malignancy in IBD patients in Crete is 4.5%. CD disease location and behavior are associated with the development of malignancies. No association with biologics and/or IMMs previous exposure was found. Moreover, initiation of biologics or IMMs after cancer diagnosis was not associated with an adverse impact either on survival or on cancer recurrence.