The role of high-magnification-chromoscopic colonoscopy in hereditary nonpolyposis colorectal cancer screening: a prospective "back-to-back" endoscopic study.
BACKGROUND
In hereditary nonpolyposis colorectal cancer flat and diminutive adenomas occur, particularly in the right colon. Such lesions may assume a high risk of malignant transformation. Interval cancers are known to occur in this group. Chromoscopic colonoscopy enhances detection in patients assuming a moderate to high lifetime risk of colorectal cancer.


OBJECTIVE
To prospectively assess the efficacy of high-magnification-chromoscopic colonoscopy for the detection of neoplastic lesions in patients undergoing hereditary nonpolyposis colorectal cancer screening.


METHODS
Twenty-five asymptomatic patients fulfilling modified Amsterdam criteria underwent "back-to-back" colonoscopy. Conventional colonoscopy with targeted chromoscopy was performed initially followed by pan-colonic chromoscopic colonoscopy. Diagnostic extubation times and volumes of normal saline and indigo carmine (IC) were controlled.


RESULTS
Using conventional colonoscopy and targeted chromoscopy 24 lesions were detected in 13 patients (20 exophytic/4 flat). Pan-colonic chromoscopy identified a further 52 lesions in 16 patients (17 exophytic/35 flat). Pan-chromoscopy identified significantly more adenomas than conventional colonoscopy (p= 0.001) and a significantly high number of flat adenomas (p= 0.004).


CONCLUSIONS
Pan-colonic chromoscopic colonoscopy improves detection of significant neoplastic lesions in hereditary nonpolyposis colorectal cancer screening. Pan-chromoscopy may help better stratify colorectal cancer "risk" in this cohort and aid planning of surveillance colonoscopic follow-up.
Hurlstone
David P
DP
Gastroenterology and Liver Unit at the Royal Hallamshire Hospital Sheffield, United Kingdom.
Karajeh
Mohammed
M
Cross
Simon S
SS
McAlindon
Mark E
ME
Brown
Steve
S
Hunter
Michael D
MD
Sanders
David S
DS
D000328:Adult; D003113:Colonoscopy / Q000379:methods*; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000473:pathology*; D004396:Coloring Agents; D005260:Female; D006801:Humans; D007203:Indigo Carmine; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D004396:Coloring Agents; D007203:Indigo Carmine