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Screening for Nonpolypoid Colorectal Neoplasms—Reply

Screening for Nonpolypoid Colorectal Neoplasms—Reply In Reply: In response to Dr Pickhardt and colleagues, in our flat lesion study we used standard terminology (the Japanese Society for Cancer of the Colon and Rectum1) that is used in other clinical studies. In a previous publication,2 Pickhardt et al used the same definition of flat lesion: “a shallow plaquelike broad-based lesion with a height of less than one half of its width.” Although “flat” colorectal neoplasms may be slightly elevated compared with the normal mucosa, their detection during high-resolution colonoscopy relies on color change, absence of vascularity, wall defect, and friability. In the World Health Organization classification for colorectal neoplasia,3 which we used in our study, the term carcinoma in situ is interchangeable with high-grade dysplasia. Although there may be a tendency to avoid the term carcinoma, this is irrelevant to the pathologic criteria or the implication of the diagnosis. After adjusting for lesion size, the association of a nonpolypoid lesion with carcinoma in situ was significant (odds ratio, 19.36; 95% confidence interval, 5.49-68.24); there was a nonsignificant association with invasive cancer (odds ratio, 3.32; 95% confidence interval, 0.94-11.72). In our screening cohort, we found 1 depressed invasive cancer and 1 flat lesion with carcinoma in situ. Although our study may have limitations in generalizability, the prevalence of nonpolypoid colorectal neoplasms (NP-CRN) we reported is similar to rates found in studies of other populations.4 We did not use CT colonography, and our colonoscopy results cannot to be extrapolated to CT colonography. We do not believe that CT colonography has been shown to detect NP-CRN sufficiently. The validity of the supporting study cited by Pickhardt et al5 can be questioned because the quality of colonoscopy did not meet recommended acceptable indicators. There was a high reported rate of perforation (7/3163; 0.22%) during colonoscopy, more than twice a recommended acceptable rate of 0.1%6; this might have limited the observed sensitivity. Other radiology investigators have shown that CT colonography is inadequate to detect NP-CRN.7 We believe that no patients should develop interval cancer. The National Polyp Study provided the basis to practice colonoscopy with polypectomy to reduce the risks of developing colorectal cancer. However, the technology and technique used to detect NP-CRN were not established at that time, and it is difficult to precisely reconstruct the endoscopic appearance of a lesion retrospectively. Our preliminary results suggest that we found fewer interval cancers compared with the VA Cooperative Study No. 380. Back to top Article Information Financial Disclosures: None reported. References 1. Yasutomi M, Baba S, Hojo K, et al. Japanese Classification of Colorectal Carcinoma. 1st ed. Tokyo, Japan: Kanehara & Co Ltd; 1997 2. Pickhardt PJ, Nugent PA, Choi JR, Schindler WR. Flat colorectal lesions in asymptomatic adults: implications for screening with CT virtual colonoscopy. AJR Am J Roentgenol. 2004;183(5):1343-134715505301PubMedGoogle ScholarCrossref 3. Hamilton SR, Aaltonen LA. World Health Organization Classification of Tumours: Pathology and Genetics: Tumours of the Digestive System. Lyon, France: IARC Press; 2000 4. Soetikno R, Friedland S, Kaltenbach T, Chayama K, Tanaka S. Nonpolypoid (flat and depressed) colorectal neoplasms. Gastroenterology. 2006;130(2):566-57616472608PubMedGoogle ScholarCrossref 5. Kim DH, Pickhardt PJ, Taylor AJ, et al. CT colonography versus colonoscopy for the detection of advanced neoplasia. N Engl J Med. 2007;357(14):1403-141217914041PubMedGoogle ScholarCrossref 6. Rex DK, Petrini JL, Baron TH, et al. Quality indicators for colonoscopy. Am J Gastroenterol. 2006;101(4):873-88516635231PubMedGoogle ScholarCrossref 7. Park SH, Ha HK, Kim MJ, et al. False-negative results at multi-detector row CT colonography: multivariate analysis of causes for missed lesions. Radiology. 2005;235(2):495-50215770042PubMedGoogle ScholarCrossref http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png JAMA American Medical Association

Screening for Nonpolypoid Colorectal Neoplasms—Reply

JAMA , Volume 299 (23) – Jun 18, 2008

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Publisher
American Medical Association
Copyright
Copyright © 2008 American Medical Association. All Rights Reserved.
ISSN
0098-7484
eISSN
1538-3598
DOI
10.1001/jama.299.23.2743-b
Publisher site
See Article on Publisher Site

Abstract

In Reply: In response to Dr Pickhardt and colleagues, in our flat lesion study we used standard terminology (the Japanese Society for Cancer of the Colon and Rectum1) that is used in other clinical studies. In a previous publication,2 Pickhardt et al used the same definition of flat lesion: “a shallow plaquelike broad-based lesion with a height of less than one half of its width.” Although “flat” colorectal neoplasms may be slightly elevated compared with the normal mucosa, their detection during high-resolution colonoscopy relies on color change, absence of vascularity, wall defect, and friability. In the World Health Organization classification for colorectal neoplasia,3 which we used in our study, the term carcinoma in situ is interchangeable with high-grade dysplasia. Although there may be a tendency to avoid the term carcinoma, this is irrelevant to the pathologic criteria or the implication of the diagnosis. After adjusting for lesion size, the association of a nonpolypoid lesion with carcinoma in situ was significant (odds ratio, 19.36; 95% confidence interval, 5.49-68.24); there was a nonsignificant association with invasive cancer (odds ratio, 3.32; 95% confidence interval, 0.94-11.72). In our screening cohort, we found 1 depressed invasive cancer and 1 flat lesion with carcinoma in situ. Although our study may have limitations in generalizability, the prevalence of nonpolypoid colorectal neoplasms (NP-CRN) we reported is similar to rates found in studies of other populations.4 We did not use CT colonography, and our colonoscopy results cannot to be extrapolated to CT colonography. We do not believe that CT colonography has been shown to detect NP-CRN sufficiently. The validity of the supporting study cited by Pickhardt et al5 can be questioned because the quality of colonoscopy did not meet recommended acceptable indicators. There was a high reported rate of perforation (7/3163; 0.22%) during colonoscopy, more than twice a recommended acceptable rate of 0.1%6; this might have limited the observed sensitivity. Other radiology investigators have shown that CT colonography is inadequate to detect NP-CRN.7 We believe that no patients should develop interval cancer. The National Polyp Study provided the basis to practice colonoscopy with polypectomy to reduce the risks of developing colorectal cancer. However, the technology and technique used to detect NP-CRN were not established at that time, and it is difficult to precisely reconstruct the endoscopic appearance of a lesion retrospectively. Our preliminary results suggest that we found fewer interval cancers compared with the VA Cooperative Study No. 380. Back to top Article Information Financial Disclosures: None reported. References 1. Yasutomi M, Baba S, Hojo K, et al. Japanese Classification of Colorectal Carcinoma. 1st ed. Tokyo, Japan: Kanehara & Co Ltd; 1997 2. Pickhardt PJ, Nugent PA, Choi JR, Schindler WR. Flat colorectal lesions in asymptomatic adults: implications for screening with CT virtual colonoscopy. AJR Am J Roentgenol. 2004;183(5):1343-134715505301PubMedGoogle ScholarCrossref 3. Hamilton SR, Aaltonen LA. World Health Organization Classification of Tumours: Pathology and Genetics: Tumours of the Digestive System. Lyon, France: IARC Press; 2000 4. Soetikno R, Friedland S, Kaltenbach T, Chayama K, Tanaka S. Nonpolypoid (flat and depressed) colorectal neoplasms. Gastroenterology. 2006;130(2):566-57616472608PubMedGoogle ScholarCrossref 5. Kim DH, Pickhardt PJ, Taylor AJ, et al. CT colonography versus colonoscopy for the detection of advanced neoplasia. N Engl J Med. 2007;357(14):1403-141217914041PubMedGoogle ScholarCrossref 6. Rex DK, Petrini JL, Baron TH, et al. Quality indicators for colonoscopy. Am J Gastroenterol. 2006;101(4):873-88516635231PubMedGoogle ScholarCrossref 7. Park SH, Ha HK, Kim MJ, et al. False-negative results at multi-detector row CT colonography: multivariate analysis of causes for missed lesions. Radiology. 2005;235(2):495-50215770042PubMedGoogle ScholarCrossref

Journal

JAMAAmerican Medical Association

Published: Jun 18, 2008

References