Survival and causes of death in Italian patients with ulcerative colitis. A GISC nation-wide 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.