Risk of cancer in patients with chronic pouchitis after restorative proctocolectomy for ulcerative colitis

Abstract

Aim: The aim of this study was to evaluate the consequences of chronic pouchitis after restorative proctocolectomy for ulcerative colitis.

Method: Forty-two patients with chronic pouchitis underwent pouch endoscopy with biopsies after a median of 8.3 years of postoperative follow up. The pouchitis disease activity index (PDAI) was calculated. Morphological changes were recorded. Immunohistochemical analyses for cyclooxygenase 2 (COX-2), Ki-67 and p53 were performed, as was DNA flow cytometry. Endoscopy was also carried out in 10 patients without pouchitis and in nine healthy subjects.

Results: In patients with chronic pouchitis, the PDAI was 6 (standard error of the mean ± 4). Eighteen (43%) patients used continuous medication. The PDAI correlated positively with villous atrophy (P < 0.05). None of the pouch biopsies showed dysplasia. COX-2 immunostaining was detected in 35 (83.3%) patients with chronic pouchitis, in five (50%) without pouchitis, but in none of the normal controls. COX-2 expression correlated with mucosal atrophy (P < 0.01). In 15 (35.7%) of 42 patients with chronic pouchitis, Ki-67 immunostaining was increased, but no increase was observed in either control group (P < 0.002). No p53 immunopositivity was found, and DNA flow cytometry was normal in all pouches. One of the patients developed adenocarcinoma at the anal anastomosis.

Conclusion: No dysplastic changes were detected during the first decade after surgery. Routine follow up of patients with chronic pouchitis with a hand-sewn anastomosis may not be necessary, although a small risk of cancer seems to remain at the anal anastomosis. The follow up should be focused on at-risk groups.