Total neoadjuvant therapy of intensified chemoradiotherapy was shown to be less effective for treating patients with rectal cancer with inflammatory bowel disease (IBD) than those with sporadic rectal cancer, according to study findings presented during Digestive Disease Week 2025. However, there was still some benefit seen in these patients.
“We lacked data on how well neoadjuvant therapy works in IBD patients when compared to sporadic patients. We wanted to determine whether IBD patients experience similar benefits from neoadjuvant therapy despite the potential for increased toxicity,” stated study co-author David Liska, MD, Chair of the Department of Colorectal Surgery at Cleveland Clinic.
Study Methods and Results
Study investigators selected 92 patients with IBD-related locally advanced rectal cancer and 92 matched patients with sporadic locally advanced rectal cancer from Cleveland Clinic’s institutional registry. All of these patients had received some neoadjuvant treatment—either neoadjuvant chemoradiotherapy, short-course radiotherapy, or total neoadjuvant therapy.
The rate of pathologic complete response following neoadjuvant therapy, the primary endpoint, was 6.8% in the IBD cohort compared with 22.6% in the non-IBD group (P = .02). However, only 10% of patients in the IBD group had a poor response to neoadjuvant therapy.
The median follow-up was 37 months in the IBD group and 47 months in the sporadic rectal cancer group, with a recurrence rate of 37% vs 22.8%, respectively. The 5-year recurrence-free survival rate was lower in the IBD group (hazard ratio [HR] = 0.58; 95% confidence interval [CI] = 0.33–1.02; P = .06). There was no significant difference in the 5-year overall survival rate (HR = 0.73; 95% CI = 0.45–1.17; P = .019).
“It is encouraging that we were able to successfully treat these patients with neoadjuvant therapy. Most were able to complete the treatment, with most patients having at least a partial response to therapy. It’s a big step forward to have a large data set that shows the outcomes of IBD patients treated with neoadjuvant therapy,” Dr. Liska said.
The study investigators suggested that IBD-related tumors are more resistant to treatment due to their tumor biology and that more effective personalized neoadjuvant approaches are needed to treat these patients. “If we could find neoadjuvant therapies that would improve responses, we would likely have improved outcomes with less recurrences and better survival,” Dr. Liska concluded.
Disclosure: For full disclosures of the study authors, visit ddw.org.
