According to new findings, biopsying the flat mucosa surrounding dysplastic polyps in patients with inflammatory bowel disease (IBD) may not change clinical outcomes. The study reported in in Gastrointestinal Endoscopy.

“We have shown that performing biopsies adjacent to polypoid dysplasia in colitis is of low yield and unnecessary in the era of enhanced visualization,” Dr David T. Rubin of the University of Chicago Medicine and colleagues conclude.

Current guidelines recommend flat mucosa or “peri-polyp” biopsies for patients with IBD, Dr Rubin and his team note. But recent research suggests most dysplasia is visible and that biopsying surrounding mucosa has a low diagnostic yield, they add.

They assessed the yield of peri-polyp biopsies in 38 patients with ulcerative colitis (UC) and 18 with Crohn’s disease (CD) treated at the University of Chicago. The patients underwent a total of 102 colonoscopies that identified 129 dysplastic polypoid lesions.

There were 503 peri-polyp biopsies, including 16 with dysplasia (3.2%). About four flat mucosa biopsies were performed for each polyp. Twenty-one of the UC patients and 13 of the CD patients were followed for a median 1.7 years and had a total of 147 additional colonoscopies, which identified 37 lesions.

Seventeen patients had low-grade dysplasia (LGD) polyps, seven had high-grade dysplasia (HGD) polyps, and four had adenocarcinoma. Four patients had no dysplasia at their follow-up exam. There was no association between dysplasia on peri-polyp biopsies and the risk of HGD or cancer, the researchers found.

Size and number of dysplastic polyps were not associated with outcomes, but dysplasia grade was strongly predictive. The likelihood of HGD or cancer among patients with LGD was 5% at one year, 13% at three years, and 23% at five years. For patients with HGD, the risk was 49%, 60%, and 70%, respectively, for a hazard ratio of 7.0 (95% confidence interval, 1.8 to 26.6).

The findings of this study support a practice of performing polypectomy for polypoid lesions that are discrete and can be removed completely, followed by active surveillance, Dr Rubin and colleagues said.

However, performing biopsies of the flat mucosa adjacent to the polyp to assess for a field effect does not enhance clinical decision-making, both because of the low yield is seen with this study, but also because of the high yield of performing follow-up examinations, which identified subsequent neoplasia and allowed for additional interventions.

The researcher said, based on the results the researchers recommend follow-up for IBD patients based on polyp dysplasia grade, with a shorter interval of follow-up for patients with HGD. Such intervals for follow-up have not been defined in any prospective study, so including these risk factors can aid clinicians and patients in decision making.