Risk factors for ulcerative colitis associated colorectal cancers in a Hungarian cohort of ulcerative colitis patients

BACKGROUND: There is an increased risk of colorectal cancer (CRC) in ulcerative colitis (UC). The prevalence of UC associated CRC is different in various geographical regions. The risk depends primarily on the duration and extent of disease. AIM: The aim of the study was to identify risk factors for and epidemiology of CRC in UC patients in Veszprem province. PATIENTS AND METHODS: From our thirty-year IBD database we retrospectively studied the relevant epidemiological and clinical data of all UC patients in Veszprem province. The data of 723 UC patients (m/f: 380/343) were evaluated. The rate of familial disease was 5.2%, the rate of non-CRC related colectomies was 3.7% in our UC patients. RESULTS: CRC was diagnosed in 13 patients (m/f: 6/7, 13/8564 person year duration) during follow-up. The onset of UC in the 13 patients with UC-CRC was 34.5 (13-61) years, 4.1 years younger compared to UC patients without CRC. Mean age of UC-CRC patients at diagnosis of CRC was 50.9 (27-70) years (duration of UC: 16.5 +/- 8.2 years), almost 15 years younger than the average in sporadic CRC population in Hungary. Eight patients are still alive (survival: 67.9 (10-163) months), four patients died because of CRC (survival: 8.0 months), one died due to unrelated cause after 10 years of the diagnosis of CRC. Longer disease duration, chronic continuous disease, more extensive colitis, the presence of iron deficiency or chronic anaemia, primary sclerosing cholangitis (PSC) and dysplasia in the biopsy were identified as risk factors for developing CRC. In a logistic regression model longer disease duration, extensive colitis, PSC and dysplasia were still associated with increased risk. The cumulative risk for developing CRC after a disease duration of 10 years was 0.6% (95% CI: 0.2-1.0%), at 20 years 5.4 % (95% CI: 3.7-7.1%) and at 32 years 12.6% (95% CI: 7.0-18.2%). CRC diagnosed at surveillance colonoscopy was associated with longer survival (p = 0.04). CONCLUSION: The cumulative risk of CRC was high in our UC patients, however it was lower compared to that reported in Western European and North American studies. CRC developed approximately fifteen years earlier compared to the sporadic CRC cases. Long disease duration, extensive colitis, the presence of iron deficiency or chronic anaemia, dysplasia and primary sclerosing cholangitis (PSC) seem to be important risk factor for developing CRC in UC patients.