Survival and causes of death in Italian patients with ulcerative colitis. A GISC nationwide study.

BACKGROUND: Death rate for patients with ulcerative colitis has changed over last few decades. Recent studies indicate that cumulative long-term mortality is comparable to that in general population, and that deaths may depend on causes not strictly related to colonic disease. AIM: To evaluate overall and cause-specific mortality rate in a large group of Italian patients with ulcerative colitis.
METHODS: A total of 2,066 ulcerative colitis patients aged >18 years consecutively diagnosed in twenty Italian Gastroenterology Units between 1964 and 1995 were followed-up from diagnosis until 1997. Standardised Mortality Ratios and Relative Survival Ratios were calculated.
RESULTS: Overall mortality of patients with ulcerative colitis was comparable to that in general population with 93 deaths observed versus 92.1 expected (standardises mortality ratio, 1.0; 95% confidence interval, 0.8-1.2). Significantly higher mortality was observed in patients under 30 years of age at diagnosis (standardised mortality ratio, 2.7; 95% confidence interval, 1.3-4.9), and in those diagnosed before 1974 (standardised mortality ratio, 2.7; 95% confidence interval, 1.1-5.7). Proctocolitis and complications from surgery were mentioned in 11 and 5 certificates, respectively. A significant excess of deaths was observed for colorectal cancer (colon: standardised mortality ratio, 3.0; 95% confidence interval, 1.0-6.9; rectum: standardised mortality ratio, 4.4; 95% confidence interval, 1.2-11.3), and haemolymphopoietic neoplasms (standardised mortality ratio, 2.8; 95% confidence interval, 1.0-6.1), in particular multiple myeloma and non-Hodgkin lymphoma. A significant deficit of deaths was observed for cancer of the respiratory system (standardised mortality ratio, 0.3; 95% confidence interval, 0.1-1.0).
CONCLUSIONS: This study confirms that, also in Italy, mortality of patients with ulcerative colitis is comparable to that in general population. Only 12% of deaths were due to ulcerative colitis itself, whereas 10% of deaths were attributed to colorectal cancer. Deaths from colorectal cancer occurred, on average, 9 years after diagnosis of ulcerative colitis, suggesting that the risk of cancer is not limited to patients with long-standing colitis. As to mortality for causes unrelated to colitis, there was an excess of deaths due to malignancies of the haemolymphopoietic system.