Original articleClinical endoscopyOngoing colorectal cancer risk despite surveillance colonoscopy: the Polyp Prevention Trial Continued Follow-up Study
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Study participants
The PPT enrolled 2079 patients who had a baseline enrollment colonoscopy (T0) with at least 1 adenomatous polyp but no history of CRC. Details of the study population have been reported.11 Subjects were randomized to a dietary intervention to adopt a diet low in fat and high in fiber, fruits, and vegetables instead of their usual diet. A repeat colonoscopy was performed in 1 to 2 years (T1) to detect and remove lesions that may have been missed at the baseline colonoscopy. Subjects underwent a
Results
Of 2079 patients enrolled in the PPT, 1905 completed the study. Of those who completed the PPT, 1297 (68%) agreed to participate in the PPT-CFS and were followed for a median of 6.2 years. PPT-CFS participants compared with PPT subjects who did not participate in the PPT-CFS were more likely to be male (67% vs 59%, P < .001), more educated (78% vs 68% post–high school education, P < .001), and to have a family history of CRC (28% vs 24%, P = .03) (Table 1). During the PPT, PPT-CFS participants
Discussion
CRC developed in 9 participants during the PPT-CFS, for a rate of 1.2 cases/1000 PYO, despite undergoing a mean of more than 3 colonoscopies during the PPT. This interval cancer rate was 64% of that expected by SEER, and when cancers detected in the main PPT and the CFS were combined, the overall rate was 74% of that expected by SEER. The absolute rates were not statistically significantly different from that expected based on SEER data. Our study included a relatively prolonged (>10 years)
Acknowledgment
We acknowledge Westat, Inc, for their work as the coordinating center for the PPT-CFS.
References (30)
- et al.
Randomised controlled trial of faecal-occult-blood screening for colorectal cancer
Lancet
(1996) - et al.
Randomised study of screening for colorectal cancer with faecal-occult-blood test
Lancet
(1996) - et al.
Colorectal cancer in patients under close colonoscopic surveillance
Gastroenterology
(2005) - et al.
Five-year colon surveillance after screening colonoscopy
Gastroenterology
(2007) - et al.
Analysis of colorectal cancer occurrence during surveillance colonoscopy in the dietary Polyp Prevention Trial
Gastrointest Endosc
(2005) - et al.
Colorectal cancers found after a complete colonoscopy
Clin Gastroenterol Hepatol
(2006) - et al.
Utilization and yield of surveillance colonoscopy in the continued follow-up study of the Polyp Prevention Trial
Clin Gastroenterol Hepatol
(2009) - et al.
Colonoscopic miss rates of adenomas determined by back-to-back colonoscopies
Gastroenterology
(1997) - et al.
Prospective blinded trial of the colonoscopic miss-rate of large colorectal polyps
Gastrointest Endosc
(1991) - et al.
Computed tomographic colonography compared with colonoscopy in patients at increased risk for colorectal cancer
Gastroenterology
(2004)
Impact of colonoscopy preparation quality on detection of suspected colonic neoplasia
Gastrointest Endosc
Relative sensitivity of colonoscopy and barium enema for detection of colorectal cancer in clinical practice
Gastroenterology
Rates of new or missed colorectal cancers after colonoscopy and their risk factors: a population-based analysis
Gastroenterology
Standardized colonoscopy reporting and data system: report of the Quality Assurance Task Group of the National Colorectal Cancer Roundtable
Gastrointest Endosc
Risk of developing proximal versus distal colorectal cancer after a negative colonoscopy: a population-based study
Clin Gastroenterol Hepatol
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DISCLOSURE: All authors disclosed no financial relationships relevant to this publication.
See CME section; p. 139.