Survival After Colorectal Cancer in Patients with Ulcerative Colitis: A Nationwide Population-Based Danish Study

Abstract

Patients with ulcerative colitis (UC) are at increased risk of colorectal cancer (CRC). Little is known about how UC impacts CRC prognosis. In a nationwide population-based study we examined the CRC prognosis in UC patients compared to CRC patients without UC. From the Danish Cancer Registry and the Danish Hospital Discharge Registry, we identified all CRC patients and all patients with UC in Denmark from 1977 to 1999. We compared survival in 279 UC patients with CRC to all other 71,259 CRC patients and computed mortality rate ratios (MRR). We also compared stage distribution at time of cancer diagnosis. The mean age at time of CRC diagnosis was 62.6 yr in UC patients and 71.2 yr in patients without UC. Cancer stage distribution for localized cancer, regional spread, and distant metastasis were 46.6%, 30.1%, and 16.5% in UC patients compared to 44.0%, 28.3%, and 19.4% in CRC patients without UC. The overall MRR for UC patients with CRC compared with all other CRC patients were 1.24 (95% CI 1.02-1.51) in the first year and 1.17 (95% CI 1.01-1.36) after 5 yr of follow-up. UC patients with CRC have a stage distribution similar to patients with CRC without UC. The prognosis of CRC is poorer for UC patients than for patients without UC.