Chromoendoscopic colonoscopy for detecting preneoplastic lesions in hereditary nonpolyposis colorectal cancer syndrome.
OBJECTIVE
In hereditary nonpolyposis colorectal cancer (HNPCC) syndrome, flat and small adenomas are particularly prone to malignant transformation but might be missed by standard colonoscopy. We prospectively studied the diagnostic yield of high-resolution colonoscopy coupled with chromoendoscopy for preneoplastic and neoplastic colorectal lesions in patients with HNPCC syndrome.


METHODS
Thirty-six consecutive asymptomatic patients (mean age, 42 years) belonging to HNPCC families and receiving genetic counseling were enrolled in this prospective study. Colonoscopy was performed in 2 steps. Conventional colonoscopy was performed first, followed by a second colonoscopy with chromoendoscopy with indigo carmine (.4%) dye sprayed onto the entire proximal colon.


RESULTS
Conventional colonoscopy identified 25 lesions (mean size, 4 +/- 3 mm) in 13 patients. Seven lesions, detected in 5 patients, were adenomas, 3 of which were located in the proximal colon. Chromoendoscopy identified additional 45 lesions (mean size, 3 +/- 1 mm) in 20 patients; most of these lesions were flat and hyperplastic. Eleven additional adenomas were detected in the proximal colon of 8 patients, and 8 of these 11 lesions were flat. The use of chromoendoscopy significantly increased the detection rate of adenomas in the proximal colon, from 3 of 33 patients to 10 of 33 patients (P = .045).


CONCLUSIONS
Relative to conventional colonoscopy, high-resolution colonoscopy with chromoendoscopy markedly improves the detection of adenomas in patients with HNPCC syndrome and might help to prevent colorectal carcinoma in these patients with a very high risk of colorectal cancer.
Lecomte
Thierry
T
Service d'Hépato-gastro-entérologie, Hôpital Européen Georges Pompidou, 20 Rue Leblanc, 75015 Paris, France.
Cellier
Christophe
C
Meatchi
Tchao
T
Barbier
Jean Philippe
JP
Cugnenc
Paul Henri
PH
Jian
Raymond
R
Laurent-Puig
Pierre
P
Landi
Bruno
B
D048868:Adaptor Proteins, Signal Transducing; D000236:Adenoma / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D000328:Adult; D000368:Aged; D002352:Carrier Proteins / Q000235:genetics; D003106:Colon / Q000473:pathology; D003113:Colonoscopy; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D005260:Female; D020022:Genetic Predisposition to Disease; D018095:Germ-Line Mutation / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D010865:Pilot Projects; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D011446:Prospective Studies
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein