Gastroenterology

Gastroenterology

Volume 124, Issue 4, April 2003, Pages 880-888
Gastroenterology

Rapid Communications
Methylene blue-aided chromoendoscopy for the detection of intraepithelial neoplasia and colon cancer in ulcerative colitis,☆☆

https://doi.org/10.1053/gast.2003.50146Get rights and content

Abstract

Background & Aims: Timely diagnosis of intraepithelial neoplasias (IN) and colitis-associated colon carcinomas (CRC) is crucially important for the treatment of ulcerative colitis (UC). We performed a randomized, controlled trial to test whether chromoendoscopy (CE) might facilitate early detection of IN and CRC in UC. Methods: A total of 263 patients with long-standing UC (≥8 years) were screened for potential inclusion in the study, 165 of whom were randomized at a 1:1 ratio to undergo conventional colonoscopy or colonoscopy with CE using 0.1% methylene blue. Five mucosal biopsy specimens were taken every 10 cm between the rectum and cecum. Circumscript lesions in the colon were evaluated according to a modified pit pattern classification. Results: In the CE group, there was a significantly better correlation between the endoscopic assessment of degree (P = 0.0002) and extent (89% vs. 52%; P < 0.0001) of colonic inflammation and the histopathologic findings compared with the conventional colonoscopy group. More targeted biopsies were possible, and significantly more IN were detected in the CE group (32 vs. 10; P = 0.003). Using the modified pit pattern classification, both the sensitivity and specificity for differentiation between non-neoplastic and neoplastic lesions were 93%. Conclusions: Based on our prospective randomized trial, CE permits more accurate diagnosis of the extent and severity of the inflammatory activity in UC compared with conventional colonoscopy. In addition, CE with methylene blue is a novel tool for the early detection of IN and CRC in patients with UC. These findings have important implications for medical and surgical interventions.

Section snippets

Patients and methods

Consecutive patients with clinically inactive, long-standing UC (≥8 years) were recruited from the outpatient clinic of the First Department of Medicine at the University of Mainz (Mainz, Germany). Suitable patients were identified using the inclusion and exclusion criteria specified in Table 1.

. Study Criteria

Inclusion criteria
 Clinically and histologically verified UC
 Disease duration ≥8 years
 Colitis Activity Index <8
 Activity index of Truelove and Witts: mild
Exclusion criteria
 Known

Patient demographics

A total of 263 consecutive patients with previously diagnosed UC from the outpatient clinic of the First Department of Medicine at the University of Mainz were screened for possible inclusion in the present study, 89 of whom were excluded (Figure 1).20

. Flow diagram of the progress through the phases of the actual randomized trial according to the CONSORT statement. Data from Moher et al.20.

A total of 174 patients fulfilled all inclusion criteria and were enrolled in the study, which was

Discussion

Long-standing UC is associated with a significantly increased risk for the development of intraepithelial neoplasias and colitis-associated carcinomas.3, 4, 5, 6 Only timely diagnosis of early neoplastic changes with serial surveillance colonoscopies allows preventive proctocolectomy in UC. However, the detection of early neoplastic lesions is challenging, even for the experienced endoscopist. In particular, only 20%-50% of intraepithelial neoplasias can be detected by routine colonoscopy.18

References (29)

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Address requests for reprints to: Ralf Kiesslich, M.D., I. Med. Klinik und Poliklinik, Johannes Gutenberg Universität Mainz, Langenbeckstrasse 1, 55101 Mainz, Germany. e-mail: [email protected]; fax: (49) 6131-175552.

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0016-5085/03/$30.00

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