Although the risk of colorectal cancer (CRC) is increased in individuals with inflammatory bowel disease (IBD), no significant discrepancy in survival rates was identified among patients with rectal cancer and IBD vs those with rectal cancer without IBD, according to the results of a study published in Diseases of the Colon & Rectum.
A team of investigators from the Mayo Clinic, in Rochester, Minnesota, conducted a retrospective cohort study in which adult patients with IBD diagnosed with rectal cancer who had at least 1 year of postsurgical follow-up were included and paired with patients with rectal cancer who did not have IBD. The objective for the research was to identify and compare survival rates between the rectal cancer IBD group and the rectal cancer non-IBD counterparts. Outcomes included 5-year overall survival and disease-free survival, as well as 30-day postoperative complication, readmission, reoperation, and mortality rates.
A total of 322 patients were included in the study: 107 patients with IBD and rectal cancer and 215 control patients. The median age was 53 years (range, 23-88 years), and 71% (n=229) were men. Preoperative analysis of rectal cancer stages revealed 31% with stage I, 19% with stage II, 40% with stage III, and 10% with stage IV.
The investigators found differences (IBD vs non-IBD) in use of neoadjuvant chemotherapy (33.6% vs 52.6%, P=.001) and preoperative radiotherapy (35.5% vs 53.5%, P=.003). Postoperative complication rates were found to be indistinguishable between the 2 groups. Regarding surgical pathology, patients with IBD were found to have more lymphovascular invasion (12.9% vs 5.6%, P=.004) and positive circumferential resection margins (5.4% vs 0.9%, P=.03).
Although the study was limited by its retrospective design and inclusion of data from a single IBD referral center, the researchers determined that the diagnosis of IBD did not have a notable effect on long-term mortality or disease-free survival rates in patients with rectal cancer. These findings suggest that long-term and disease-free survival associated with rectal cancer is the same in patients with and without IBD, despite lower rates of neoadjuvant treatment and higher margin positivity in patients with IBD. A deeper understanding of the differences between patients with isolated rectal cancer and IBD in relation to patients who have CRC and IBD is important and can possibly lead to better treatment protocols and subsequently better patient outcomes.
Disclosure: A study author declared an affiliation with the pharmaceutical industry.
Alsughayer A, Grass F, McKenna NP, Petersen M, Mathis KL, Lightner AL. Does IBD portend worse outcomes in patients with rectal cancer? A case-matched analysis. Dis Colon Rectum. 2020;63(9):1265-1275. doi:10.1097/DCR.0000000000001666