Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Multicenter study looks at colon polyps

05.12.2006
Medium-sized polyps yield significant number of advanced adenomas and cancer

According to a University of Pittsburgh-led study published in the December issue of Gastroenterology, medium-sized polyps found in the colon with flexible sigmoidoscopy and subsequently evaluated by full colonoscopy are associated with a significant number of advanced adenomas (high-risk polyps) and cancers.

These findings raise questions about taking a "wait and watch" approach to medium-sized polyps and delaying referral to colonoscopy, a strategy which could become more popular with newer screening tests that are observational and do not remove polyps, such as virtual colonoscopy.

The study included 10,850 men and women enrolled in the Prostate, Lung, Colorectal and Ovarian Cancer (PLCO) Screening Trial, a randomized, community-based study evaluating the effectiveness of cancer screening tests on site-specific mortality at 10 centers throughout the United States. The participants in the study had an abnormal flexible sigmoidoscopy with at least one detectable polyp and subsequently underwent a diagnostic colonoscopy within one year.

"An emerging issue in colorectal cancer screening is the management of medium-sized polyps, since many new technologies under development can only observe the lining of the colon, and do not offer the ability to remove polyps," said Robert Schoen, M.D., M.P.H, lead author of the study and professor of medicine and epidemiology, University of Pittsburgh School of Medicine. "With these new methods, colonoscopy and polyp removal are required as second procedures, but because of issues of expense and risk, determining a specific threshold for subsequent procedures becomes an important issue. One area of uncertainty concerns medium-sized polyps. In our study, individuals with medium-sized polyps 0.6 - 0.9 cm were found to have a significant yield of advanced adenomas and even cancer, making an observational strategy in this setting potentially risky."

In the study, polyps 0.6 - 0.9 cm were found in 2,183 men and 1,426 women through flexible sigmoidoscopy, in which a scope is used to examine the inside of the large intestine from the rectum through the descending colon. Flexible sigmoidoscopy differs from colonoscopy in that only a portion of the colon is examined, whereas with colonoscopy the entire colon is examined. When the men and women in the study underwent diagnostic colonoscopy within a year, 14.5 percent of the women and 15.9 percent of the men were diagnosed with advanced adenomas (pre-cancerous polyps or growths in the lining of the large intestine that are at higher risk for developing into cancer), and 0.6 percent of the women and 0.7 percent of the men were diagnosed with cancer. In some cases, the medium-sized polyps were considered large when removed and assessed at colonoscopy. In other cases, the small polyps had important, adverse pathologic characteristics once removed and studied under the microscope.

"The implication of our study is that where we draw the line when assessing and evaluating polyp size and referral to colonoscopy has to be carefully considered," said Dr. Schoen. "These results offer a cautionary note to waiting and watching."

Colorectal cancer is a worldwide public health problem. In the United States, colorectal cancer accounts for 11 percent of all cancers, with 148,610 new cases and 55,170 deaths expected by the end of 2006. For patients with advanced disease, five-year survival rates are 10 percent to 20 percent. When colorectal cancer is diagnosed at an early, localized stage, the five-year survival rate is 90 percent.

Clare Collins | EurekAlert!
Further information:
http://www.upmc.edu

More articles from Studies and Analyses:

nachricht The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>