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Updated: May 11, 2026
Evaluation of Colorectal Cancer Risk and Prevalence by Stool DNA Integrity Detection
Published on: June 8, 2020
Identification of patients with developing ulcerative colitis-associated neoplasia by nitrative DNA damage marker
Susumu Saigusa1, Toshimitsu Araki, Koji Tanaka
1Department of Gastrointestinal and Pediatric Surgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan.
Goal:
To clarify whether the expression of nitrative and oxidative DNA damage markers in the rectal mucosa of patients with ulcerative colitis (UC) could be used to predict UC-associated neoplasia.
Background:
A longer duration of UC can increase the risk of developing UC-associated cancer (UCAC). Effective diagnostic markers are being sought to provide more selective screening and treatment strategies for patients with long-standing UC.
Study:
A total of 141 patients with UC who underwent a proctocolectomy were enrolled in this study. The expression of 8-nitroguanine (8-NG), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), and inducible nitric oxide synthase (iNOS) in the rectal mucosa were evaluated using immunohistochemistry (IHC) and assessed relative to the pathogenesis of UC-associated neoplasia.
Results:
Eighteen patients (12.8%) had UC-associated neoplasia including low-grade or high-grade dysplasia and UCAC. IHC scores of 8-NG in UC-associated neoplasia group was significantly higher than in non-neoplasia group (P<0.0001). In contrast, IHC score of 8-oxodG in non-neoplasia group was significantly decreased compared with UC-associated neoplasia group (P=0.0028). In logistic regression analysis, duration of disease >8 years, high IHC scores of 8-NG, and low 8-oxodG in the rectal mucosa were significantly associated with the development of UC-associated neoplasia (P<0.01). The expression of 8-NG was more frequently observed in patients with UCAC than in patients with sporadic colorectal cancer (P<0.01).
Conclusion:
These results suggest that evaluating the expression levels of 8-NG in the rectal mucosa may be a useful biomarker for detecting patients with UC-associated neoplasia.
