Improved Early Detection Of Colorectal Cancer..

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Improved Early Detection Of Colorectal Cancer Made Possible By

Advances In Screening And Markers

28 May 2007

Although colorectal cancer is the second leading cause of cancer

death in the United States, when detected early, it has one of the

highest cure rates. For this reason, innovative and improved methods

to screen for and detect this disease are essential. Research

presented at Digestive Disease Week® 2007 (DDW®) demonstrates the

breadth of technological and research advances that are helping to

decrease both the number of deaths and the number of new cases of

colorectal cancer diagnosed in the United States. DDW is the largest

international gathering of physicians and researchers in the fields

of gastroenterology, hepatology, endoscopy and gastrointestinal

surgery.

A New Benchmark in the Colorectal Neoplasm Miss Rate During

Colonoscopy: Results of a Randomized Controlled Trial of Wide Angle

View (170 degrees) Colonoscopy Comparing Narrow Band Imaging and

White Light (Abstract #821)

Although the colonoscopy is considered the most effective means to

detect precursors of colon cancer, the overall reported rate of

missing colorectal tumors is 24 percent, as reported in 1997. In the

past 10 years, significant advances in screening technologies have

led to the development of colonoscopes (long, flexible, lighted tubes

with attached cameras) that have a wider angle of view and non-white

light capabilities, such as narrow band imaging (NBI). Researchers

from the Veterans Affairs Palo Alto Medical Center in Palo Alto,

Calif. utilized current technologies to study the colonoscopic polyp

miss rate, comparing NBI to white light imaging.

NBI changes the white light normally emitted by the colonoscope to a

bluish light, providing a narrower wavelength and enhancing visual

contrast of the surface structure of the colon. In this study, two

consecutive, same-day colonoscopies were performed in 276 patients.

All colonoscopies used a wide angle of view (170 degrees compared to

standard 140) and high resolution capabilities. The patients were

randomly assigned to white light (141 patients) or NBI (135 patients)

during the first withdrawal, and then immediately underwent a second

examination by the same physician using white light.

The study found an overall miss rate of 12 percent for tumors of any

size and three percent for tumors greater than or equal to six

millimeters. No lesion larger than one centimeter was missed and all

missed tumors were tubular adenomas, or non-cancerous tumors. Based

on these results, researchers established the colorectal tumor miss

rate as zero percent (up to 2%) for significant tumors and 12 percent

for all tumors. However, no significant difference of missed lesions

was found between NBI and white light.

" Our findings suggest that technological advances have led to a

significant reduction in the overall colorectal tumor miss rate,

establishing a new benchmark for more accurate screening and

detection, " said Roy Soetikno, M.D., of Stanford University in

Stanford, Calif., and senior author of the study. " Our study

reaffirms the role of colonoscopy as the gold standard method to

screen for colorectal cancer. "

The Association of Elevated C-Reactive Protein Levels with

Synchronous and Advanced Colorectal Adenoma (Abstract #S1987)

Inflammation has been implicated in numerous diseases through recent

research. High levels of C-reactive protein (CRP) - a protein found

in the blood that can be used to detect or grade inflammation - are

often associated with cardiovascular disease and cancers, such as

colorectal cancer. Little is known, however, about CRP levels and non-

cancerous colorectal tumors (adenomas) that precede colorectal

cancer. Researchers from National Taiwan University Hospital in

Taipei, Taiwan, examined levels of CRP in both men and women, finding

that elevated levels may be associated with increased risk of

colorectal adenoma, but only in men.

Study authors conducted a cross-sectional study of plasma CRP levels

in 6,695 Chinese patients. All patients underwent a complete total

colonoscopy and thorough health check-up. Results were adjusted for

age, gender, history of colon polyp, diabetes, hypertension,

hypertriglyceridemia, hypercholesterolemia, physical activity,

alcohol intake, smoking, white blood cell counts and abdominal

obesity.

Results demonstrated that plasma CRP levels were significantly higher

in patients in whom colorectal tumors were forming when compared to

patients without tumor development. The presence of tumors forming at

the same time, known as synchronous neoplasia, and advanced tumor

development were associated with elevated levels of plasma CRP.

However, while researchers found that high CRP levels are associated

with the risk of colorectal tumor formation in male patients, the

study did not find a corresponding association with female patients.

" These findings support the crucial role of chronic inflammation in

the development of colorectal cancer, " said Han-Mo Chiu, M.D., of the

National Taiwan University Hospital, and senior author of this

study. " These data warrant further investigations that will continue

to evaluate C-reactive protein levels as an indicator of colorectal

cancer and examine the gender differences found in our study. "

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Digestive Disease Week® (DDW®) is the largest international gathering

of physicians, researchers and academics in the fields of

gastroenterology, hepatology, endoscopy and gastrointestinal surgery.

Jointly sponsored by the American Association for the Study of Liver

Diseases (AASLD), the American Gastroenterological Association (AGA)

Institute, the American Society for Gastrointestinal Endoscopy (ASGE)

and the Society for Surgery of the Alimentary Tract (SSAT), The

meeting showcases more than 5,000 abstracts and hundreds of lectures

on the latest advances in GI research, medicine and technology.

Contact: Aimee

American Gastroenterological Association

Article URL: http://www.medicalnewstoday.com