Colon cancer is the second leading cause of cancer related deaths in the United States. Specificity in diagnostic imaging
for detecting colorectal adenomas, which have a propensity towards malignancy, is desired. Adenomatous polyp specimens of the colon were obtained from the mouse model of colorectal cancer called adenomatous polyposis coli-multiple intestinal neoplasia (APCMin). Histological evaluation, by the legume protein Ulex europaeus agglutinin I (UEA-1), determined expression of the glycoprotein α-L-fucose. FITC-labelled UEA-1 confirmed overexpression of the glycoprotein by the polyps on fluorescence microscopy in 17/17 cases, of which 13/17 included paraffin-fixed mouse polyp specimens. In addition, FITC-UEA-1 ex vivo multispectral optical imaging of 4/17 colonic specimens displayed over-expression of the glycoprotein by the polyps, as compared to non-neoplastic mucosa. Here, we report the surface expression of α-L-fucosyl terminal residues by neoplastic mucosal cells of APC specimens of the mouse. Glycoprotein expression was validated by the carbohydrate binding protein UEA-1. Future applications of this method are the development of agents used to diagnose cancers by biomedical imaging modalities, including computed tomographic colonography (CTC). UEA-1 targeting to colonic adenomas may provide a new avenue for the diagnosis of colorectal carcinoma by CT imaging.
We have found greater difficulty achieving desirable sensitivities and specificities with our computer-aided detection
(CAD) system on polyps sized 6-9 mm. Missed polyps in our ground truth CAD training datasets could be one possible
cause. Most CT colonography (CTC) protocols require supine and prone scans therefore the number of polyps visible to
a radiologist in at least one scan may increase. However, registration of a specific polyp visible in both scans can prove
difficult without a uniform coordinate system. Using a teniae coli registration tool we hypothesized we could register
and find a statistically significant number of 6-9 mm polyps believed to be not findable in one scan subsequently
reducing error in the training data and enabling better training of our CAD system. Database queries yielded 20 polyps
initially believed to be not findable in one scan. The teniae coli navigation and registration system allowed us to identify
30% (6/20) of the polyps as matches with confidence in both scans (rating 1) and 10% (2/20) of the polyps with a
potential match with some uncertainty (rating 2). No convincing match was found for 60% (12/20) of polyps (rating 3).
We conclude that this teniae coli registration tool is an effective means of identifying and reducing ground truth data
errors in 6-9 mm polyps initially believed not findable in one scan. The use of this tool has the potential to improve the
performance of a CAD system on the more difficult 6-9 mm polyps.