Dysplasia and colorectal cancer in ulcerative colitis develop via pathways distinct from sporadic colorectal cancer.
Colorectal cancer in those patients may occur in flat mucosa indistinct from surrounding tissue.
Surveillance guidelines, therefore, have emphasized the roach of periodic endoscopic examinations and systematic random biopsies of involved mucosa.
Given the imperfect nature of this random approach, recent work has focused on improved surveillance techniques.
The findings suggest that neoplasia is endoscopically visible in many patients.
Dr David Rubin and colleagues from Chicago, Illinois assessed the endoscopic visibility of dysplasia and colorectal cancer in ulcerative colitis.
The researchers conducted a retrospective review that used the University of Chicago Inflammatory Bowel Disease Registry and the clinical administrative database.
All cases of dysplasia or colorectal cancer in ulcerative colitis between 1994 and 2004 were identified.
|Per-patient sensitivity for cancer was 100%|
The approach to surveillance in these patients included random biopsies at approximately 10-cm intervals throughout the involved colon.
The team also applied directed biopsies of polypoid lesions, masses, strictures, or irregular mucosa distinct from surrounding inflamed tissue.
Findings on endoscopy were compared with pathologic findings from biopsy or surgical specimens.
The researchers defined visible dysplasia as a lesion reported by the endoscopist that led to directed biopsy.
In addition, the lesion was confirmed by pathology.
The team defined invisible dysplasia as dysplasia diagnosed on pathology but not described on endoscopy.
Per-lesion and per-patient sensitivities were determined.
In this database, there were 1339 surveillance examinations in 622 patients with ulcerative colitis.
The team found that 46 patients had dysplasia or colorectal cancer at a median age of 48 years, and with median duration of disease of 20 years.
Of these patients, 77% had pancolitis, 21% had left-sided colitis, and 2% had proctitis.
These patients had 128 surveillance examinations, and, in 51 examinations, 75 separate dysplastic or cancerous lesions were identified.
The team noted that 59% of dysplastic lesions and 80% of cancers were visible to the endoscopist as polyps and masses, strictures, or irregular mucosa.
The research team observed that per-patient sensitivities for dysplasia and for cancer were 72% and 100%, respectively.
The overall per-lesion and per-patient sensitivities were 61% and 76%, respectively.
Dr Rubin's team commented, "Dysplasia and cancer in ulcerative colitis are endoscopically visible in most patients and may be reliably identified during scheduled examinations."
"Future surveillance guidelines should incorporate this information."