Brief Article
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World J Gastroenterol. Dec 28, 2013; 19(48): 9359-9365
Published online Dec 28, 2013. doi: 10.3748/wjg.v19.i48.9359
Risk of cancer, with special reference to extra-intestinal malignancies, in patients with inflammatory bowel disease
Alicia Algaba, Iván Guerra, Ángel Castaño, Gema de la Poza, Víctor M Castellano, Montserrat López, Fernando Bermejo
Alicia Algaba, Iván Guerra, Gema de la Poza, Fernando Bermejo, Department of Gastroenterology, Hospital Universitario de Fuenlabrada, 28942 Madrid, Spain
Ángel Castaño, Víctor M Castellano, Montserrat López, Department of Pathology, Hospital Universitario de Fuenlabrada, 28942 Madrid, Spain
Author contributions: All authors made substantial contributions to the concept and design of the study, acquisition, analysis and interpretation of data, and all of them read and approved the final version of the manuscript.
Correspondence to: Alicia Algaba, MSc, Department of Gastroenterology, Hospital Universitario de Fuenlabrada, Camino del Molino, 2, Fuenlabrada, 28942 Madrid, Spain. alicia_algaba@hotmail.com
Telephone: +34-69-9646717 Fax: +34-91-6006175
Received: August 4, 2013
Revised: September 20, 2013
Accepted: October 19, 2013
Published online: December 28, 2013
Abstract

AIM: To determine the incidence and characteristics of intestinal and extra-intestinal cancers among patients with inflammatory bowel disease in a Spanish hospital and to compare them with those of the local population.

METHODS: This was a prospective, observational, 7-year follow-up, cohort study. Cumulative incidence, incidence rates based on person-years of follow-up and relative risk were calculated for patients with inflammatory bowel disease and compared with the background population. The incidence of cancer was determined using a hospital-based data registry from Hospital Universitario de Fuenlabrada. Demographic data and details about time from diagnosis of inflammatory bowel disease to occurrence of cancer, disease extent, inflammatory bowel disease treatment, cancer therapy and cancer evolution were also collected in the inflammatory bowel disease cohort.

RESULTS: Eighteen of 590 patients with inflammatory bowel disease developed cancer [cumulative incidence = 3% (95%CI: 1.58-4.52) vs 2% (95%CI: 1.99-2.11) in the background population; RR = 1.5; 95%CI: 0.97-2.29]. The cancer incidence among inflammatory bowel disease patients was 0.53% (95%CI: 0.32-0.84) per patient-year of follow-up. Patients with inflammatory bowel disease had a significantly increased relative risk of urothelial carcinoma (RR = 5.23, 95%CI: 1.95-13.87), appendiceal mucinous cystadenoma (RR = 36.6, 95%CI: 7.92-138.4), neuroendocrine carcinoma (RR = 13.1, 95%CI: 1.82-29.7) and rectal carcinoid (RR = 8.94, 95%CI: 1.18-59.7). Colorectal cancer cases were not found.

CONCLUSION: The overall risk of cancer did not significantly increase in our inflammatory bowel disease patients. However, there was an increased risk of urinary bladder cancer and, with less statistical power, an increased risk of appendiceal mucinous cystadenoma and of neuroendocrine tumors. Colorectal cancer risk was low in our series.

Keywords: Extra-intestinal cancer, Inflammatory bowel disease, Cancer risk, Background population, Urothelial carcinoma, Appendiceal mucinous cystadenoma, Neuroendocrine carcinoma, Rectal carcinoid

Core tip: Several studies have reported increased rates of colorectal cancer in patients with inflammatory bowel diseases but limited data are available regarding incidence of extraintestinal malignancies in these patients. The present study demonstrates a higher risk of urinary bladder cancer, mucinous cystadenoma of the appendix and of neuroendocrine tumors, and a low colorectal cancer risk, in patients with inflammatory bowel disease in our environment. We raised the question of whether current cancer screening strategies need to be reviewed and adapted to the characteristics of each patient.