Characteristics and outcomes of rectal cancer in patients with inflammatory bowel disease: a single-center experience

The increased risk of colorectal cancer (CRC) in patients with inflammatory bowel disease (IBD) has been well documented in the literature. The present study aimed to assess the characteristics and outcomes of rectal cancer in patients with IBD. This study was a retrospective review of a prospectively maintained IRB-approved database at Cleveland Clinic Florida. Rectal cancer patients with or without IBD treated with curative surgery between 2016 and 2020 were compared for demographics, disease characteristics, and pathologic and oncologic outcomes. The primary outcomes were 3-year overall survival (OS) and disease-free survival (DFS). Secondary outcomes were clinicopathologic outcomes including disease stage, tumor histology and histologic features, and treatments received. 238 patients with rectal cancer were included, 15 (6.3%) of whom had IBD. IBD patients were significantly younger (52.9 vs 60.3 years, p = 0.033), presented more often with cT1-2 tumors (64.3% vs 30.4%, p = 0.008), and signet-ring cell pathology (14.3% vs 2%, p = 0.02). IBD patients received neoadjuvant chemoradiation less often (40% vs 72.6%, p = 0.029) and had shorter time between diagnosis and surgery (7.5 vs 25 weeks, p = 0.013) than did non-IBD patients. Both groups had similar OS (36 vs 34.7 months, p = 0.431) and DFS (36 vs 32.9 months, p = 0.121). IBD patients with rectal cancer tend to present at a younger age, with a less invasive disease, and signet-ring carcinomas, and receive neoadjuvant treatment less often than non-IBD patients. Based on low level of evidence, IBD and non-IBD rectal cancer patients might have similar survival.