Differences in Prognosis and Recurrence Patterns Between Ulcerative Colitis-Associated Colorectal Cancer and Sporadic Colorectal Cancer: A Matched-Pair Analysis.

ABSTRACT

BACKGROUND: Clinicopathological differences exist between ulcerative colitis-associated colorectal cancer (UC-CRC) and sporadic colorectal cancer (S-CRC). However, differences in the prognosis remain controversial, and the reason for these differences remains unclear. We therefore assessed the differences between patients with UC-CRC and S-CRC. PATIENTS AND METHODS: This was a matched-pair analysis of the clinicopathological characteristics and prognosis of patients with UC-CRC and S-CRC who underwent colorectal resection between January 2000 and December 2021 at two institutions. Patients were matched according to age, sex, date of surgery, tumor location, and Union for International Cancer Control (UICC) stage. RESULTS: A total of 5992 patients underwent surgery for CRC at the two institutions, and 288 patients (48 with UC-CRC and 240 with S-CRC) were matched in this study. Patients with UC-CRC underwent more invasive surgery and had a longer operative time than those with S-CRC, but there was no marked difference in postoperative complications or perioperative mortality. Long-term outcomes showed a similar 5-year overall survival (OS) for UC-CRC and S-CRC (86.5% versus 88.8%, p = 0.742); however, in stage 3 patients, patients with UC-CRC had a poorer 5-year OS than those with S-CRC (51.4% versus 83.8%, p = 0.032). The first recurrence sites in stage 3 UC-CRC were peritoneal dissemination followed by the bones, while those in S-CRC were the liver and pulmonary system. CONCLUSIONS: Despite no significant differences in surgical outcomes, patients with UC-CRC had a poorer prognosis than those with S-CRC at stage 3. The recurrence patterns in UC-CRC differed from those in S-CRC, suggesting a possible prognostic difference.