Background: Endoscopic surveillance of patients with ulcerative colitis aims to prevent cancer-related morbidity through the detection and treatment of dysplasia. The literature to date varies widely with regard to the importance of dysplasia as a marker for colorectal cancer at the time of colectomy.
Objective: The aim of this study was to accurately characterize the extent to which the preoperative detection of dysplasia is associated with undetected cancer in patients with ulcerative colitis.
Design/patients/setting: A retrospective chart review was conducted of patients undergoing surgery for colitis within the Mayo Clinic Health System between August 1993 and July 2012.
Main outcome measures: Patient demographics and pre- and postoperative dysplasia were tabulated. The relationship between pre- and postoperative dysplasia/cancer in surgical pathology specimens was assessed.
Results: A total of 2130 patients underwent abdominal colectomy or proctocolectomy; 329 patients were identified (15%) as having at least 1 focus of dysplasia preoperatively. Of these 329 patients, the majority were male (69%) with a mean age of 49.7 years. Unsuspected cancer was found in 6 surgical specimens. Indeterminate dysplasia was not associated with cancer (0/50). Preoperative low-grade dysplasia was associated with a 2% (3/141) risk of undetected cancer when present in random surveillance biopsies and a 3% (2/79) risk if detected in endoscopically visible lesions. Similarly, 3% (1/33) of patients identified preoperatively with random surveillance biopsy high-grade dysplasia harbored undetected cancer. Unsuspected dysplasia was found in 62/1801 (3%) cases without preoperative dysplasia.
Limitations: This study is limited by its retrospective nature and by its lack of evaluation of the natural history of dysplastic lesions that progress to cancer.
Conclusions: The presence of dysplasia was associated with a low risk of unsuspected cancer at the time of colectomy. These findings will help inform the decision-making process for patients with ulcerative colitis who are considering intensive surveillance vs surgical intervention after a diagnosis of dysplasia.