High Colorectal Cancer Risk in IBD Patients With Dysplasia
Long-term Swedish data clarify how low-grade and high-grade dysplasia change colorectal cancer risk in inflammatory bowel disease.
In a nationwide Swedish cohort of more than 54,000 patients with inflammatory bowel disease, the risk of colorectal cancer rose sharply in those with baseline dysplasia, reaching nearly 50-fold higher in patients with high-grade dysplasia compared with those without dysplasia.
Study Details
Chronic inflammation in Inflammatory bowel disease, including Ulcerative colitis and Crohn’s disease, has long been associated with elevated risk of Colorectal cancer. What has been less clear is how that risk varies depending on the type of dysplasia found during colonoscopic surveillance.
In this nationwide Swedish cohort study, researchers led by Jordan Axelrad, MD, MPH, analyzed data from the Swedish Patient Register and the ESPRESSO histopathology cohort. The study included 54,534 patients diagnosed with IBD between 1969 and 2023 who had at least one confirmatory colorectal biopsy.
At baseline:
53,214 had no dysplasia
264 had indefinite dysplasia
1,031 had low-grade dysplasia
25 had high-grade dysplasia
Median follow-up was approximately 13 years.
Methodology
This was a longitudinal, population-based cohort study. Researchers linked national clinical and pathology registries to:
Identify patients with confirmed IBD.
Classify baseline dysplasia status from biopsy data.
Track development of colorectal cancer or advanced neoplasia over time.
Risk was quantified using adjusted hazard ratios, accounting for confounders such as age, sex, disease subtype, duration of disease, inflammation on histology, and family history of colorectal cancer.
For general readers, this means the investigators compared large groups of patients over more than a decade and calculated how much more likely cancer was to occur in those with different precancerous findings.
Key Findings
CRC occurred in 2.1% of patients without baseline dysplasia over follow-up.
CRC occurred in 4.5% with indefinite dysplasia.
CRC occurred in 7.8% with low-grade dysplasia.
CRC occurred in 40% with high-grade dysplasia.
Low-grade dysplasia was associated with a more than threefold higher risk of CRC (aHR 3.48).
High-grade dysplasia was associated with nearly 50-fold higher risk of CRC (aHR 47.88).
Indefinite dysplasia was associated with higher risk of advanced neoplasia (aHR 1.85).
Risk factors for developing dysplasia included male sex, longer disease duration, histologic inflammation, ulcerative colitis subtype, primary sclerosing cholangitis, and family history of colorectal cancer.
Although progression from low-grade to advanced dysplasia appeared to decline over time, the overall data support continued intensive surveillance.
Implications for Practice
For patients with IBD, this study reinforces that not all dysplasia carries the same risk. A finding of high-grade dysplasia represents a markedly elevated probability of colorectal cancer and should prompt urgent surgical evaluation. Current guidelines recommending strong consideration of colectomy in these patients appear well supported.
For patients with low-grade dysplasia, the risk is meaningfully increased but not absolute. Shared decision-making becomes critical. Surveillance intervals may need to be shortened, and discussions should include the balance between continued colonoscopic monitoring and prophylactic surgery in selected cases.
For healthcare providers, the data provide quantitative reinforcement for risk stratification during IBD surveillance. Identifying and aggressively controlling mucosal inflammation remains central, as persistent inflammation correlates with future dysplasia. Counseling should consistently address cancer prevention as a core component of long-term IBD management.
Limitations, including smaller numbers of high-grade dysplasia cases and limited ethnic diversity, suggest that further validation in broader populations would be valuable. Still, the magnitude of risk observed, particularly for high-grade lesions, is difficult to ignore.