In IBD patients, when does low-grade dysplasia progress to advanced dysplasia or colorectal cancer?
Not all patients with IBD-associated colorectal dysplasia progress to cancer. The decision to continue surveillance or pursue colectomy needs to be individualized with clear communication of risk.
Cremer A, Demetter P, De Vos M, et al. Risk of Development of More-advanced Lesions in Patients with Inflammatory Bowel Diseases and Dysplasia. Clin Gastroenterol Hepatol. 2020;18(7):1528–36.e5; https://doi.org/10.1016/j.cgh.2019.05.062
Studies have yielded mixed findings on the risk of high-grade dysplasia (HGD) and colitis-related colorectal cancer (CAC) in IBD patients. To further understanding of the topic, researchers at seven medical centers in Belgium retrospectively analyzed health records from 410 IBD patients treated at their institutions between 1990 and 2016. The patients all had colorectal dysplasia, including 616 lesions with low-grade dysplasia (LGD), 64 with HGD, and 133 with CAC. The median duration of follow-up was 19 years after IBD diagnosis and the median age at IBD diagnosis was 37.
The researchers found that 7% of those with LGD developed either HGD or CAC, at median intervals of 43 and 137 months, respectively, after LGD diagnosis. Additionally, 14% of those initially diagnosed with HGD developed CAC a median of 180 months after HGD diagnosis. The ten-year incidence of CAC among those with an initial diagnosis of LGD was 8.5%. Three percent of patients had a dysplastic lesion identified prior to IBD diagnosis, 7% had dysplasia found at the time of IBD diagnosis and 27% had dysplasia found during the eight years after IBD diagnosis.
Those with CAC were significantly younger at the time of IBD diagnosis, had longer disease duration, and were more likely to have metachronous and multifocal lesions. Multivariate analyses found that the risk of progression to either HGD or CAC was highest among those with metachronous LGD (Relative Risk [RR]: 14.5; 95% Confidence Interval [CI], 3.39–61.9; P<0.01), non-polypoid lesions (RR: 20.94; 95% CI, 4.92–89.17; P<0.01) and colonic strictures (RR: 7.48; 95% CI, 3.08–18.17; P<0.01). Eighty-six percent of those with CAC did not have dysplasia diagnosed previously, and 67% of these individuals were not involved in a screening or surveillance program.
Study Design: Retrospective national cohort
Funding: Supported by the Fonds Erasme for Medical Research
Allocation: Not applicable
Setting: Multicenter health records database
Level of Evidence: 2b (Oxford Levels of Evidence)
The summary and conclusion in this issue of E-mentoring in IBD pertains to the manuscript(s) being reviewed, and should be considered in the context of what is already known surrounding the topic and incorporated into practice as deemed appropriate by the individual learner.