[Development of malignant tumors in patients with inflammatory bowel disease].

Background: The chronic inflammation of the intestinal mucosa, the extra-intestinal manifestations of the disease and the immunosuppressive treatment of inflammatory bowel disease may increase cancer risk.

Aim: To report the demographic and clinical features of patients with IBD who developed a malignant tumor.

Material And Methods: Retrospective analysis of an IBD patient registry of a private clinic, diagnosed between 1976 and 2014.

Results: 437 subjects were included, aged 15-88 years (58% women). Seventy two percent of patients had ulcerative colitis. The median time of follow up was 6 years. Ten patients (2.3%) developed a malignant tumor. In four, the tumor could be related to IBD (two colorectal cancers, one cholangiocarcinoma and one chronic myeloid leukemia (CML)). Two of 45 patients treated with biological therapy developed a tumor (CML and hypernephroma). Three of 170 patients on immunosuppressive treatment developed tumors. Only one had a tumor possibly related with the use of azathioprine (non-melanoma skin cancer). In only two patients, the treatment was changed at the time of their cancer diagnosis, from immunosuppressive medications to mesalamine.

Conclusions: Only a small proportion of these patients with IBD developed a malignant tumor. The treatment of IBD has to be determined by the severity of the disease and not by the fear of developing a neoplasia. Following recommendations is fundamental to decrease the possibility of developing this complication.