Ulcerative colitis (UC) patients have an increased risk of developing colorectal carcinoma (CRC). In contrast to clinical and pathogenetic differences, little is known about how prognosis compares between these patients and those with sporadic CRC. The aim of this study was to compare their characteristics and prognosis and identify independent risk factors for patients with UC-associated CRC.

A total of 126 patients who underwent surgery in our department (1984–2010) for UC-associated (n = 63) or sporadic (n = 63) CRC were included in this analysis. Patients were matched according to sex, tumor location, and disease stage. Clinical parameters and overall, recurrence-free, and disease-specific survival were compared. In subgroup analyses, clinical parameters of UC patients were correlated with survival.

Median follow-up was 129 months in the UC group and 99 months in the sporadic CRC group. UC patients were significantly younger and had more multifocal, high-grade, and mucinous carcinomas. Five-year overall survival rate for UC-associated and sporadic CRC was similar (65.7 vs. 63.2 %, p = 0.98). Recurrence-free survival for International Union Against Cancer (UICC) stage II disease was superior in the sporadic CRC group (p = 0.039). In a subgroup analysis of UC patients, a shorter duration of UC (p = 0.045) and male sex (p = 0.005) were associated with a worse prognosis.

Despite multiple clinical and histopathologic differences between UC-associated and sporadic CRC patients, overall survival and disease-specific survival are similar. In a subgroup analysis of UC patients with CRC, female sex was associated with a significantly better prognosis. This finding implies that estrogens may play a protective role in UC-associated CRC carcinogenesis.