Colorectal malignancies associated with inflammatory bowel (IBD) disease

Background: Individuals with ulcerative colitis (UC) and Crohn's disease (CD) are at increased risk of developing colorectal cancer (CRC). The risk is increasing with long-standing and extensive colitis.

Aims and methods: A retrospective study was made of both common and unusual parameters relating to the clinical features and behaviour of colorectal malignancies in 822 IBD patients since 1987.

Results: Eleven patients were operated on due to colorectal malignancy. The average age at the onset of UC/CD was 34.1 years (min.11, max. 61); the inflammatory process involved the transvers colon in 4, and was located below the splenic flexure in 7 cases, in another 2 cases pancolitis was observed. Two patients had small intestinal CD. The average duration of malignancy development was 23.7 years (min.12, max. 48). At the time of surgery, the mean age of the UC/CD patients was 56.2 years (min. 24, max. 79). Histology revealed adenocarcinoma in 8 cases only, as well as malignant histiocytosis, hamartoma, and in situ carcinoma was detected. Five of the 8 carcinomas were located in the rectosigmoideum, 1 each in the ascending and the descending colon and 1 in the jejunum. The histiocytosis involved the transverse colon, the hamartoma was located in the descending colon and the in situ carcinoma was in the ascending colon. The infiltrative histiocytoma, the adenocarcinoma in the CD patient and 1 rectal (adenocc. sigillocellulare) malignancy proved to be incurable with surgery; the hamartoma was curatively resected. Tumour staging highlighted Dukes A in 1 case only, and Dukes C in 3. The mothers of 2 patients also had CRC, while the father of a third patient was operated on for gastric cancer.

Conclusions: Our data suggest a higher incidence of malignancy in first-degree relatives of UC patients who develop CRC. The location of the malignancies in UC patients revealed a distal predominance.