Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

U-M researchers identify new blood test for prostate cancer

22.09.2005


Test looks at 22 biomarkers; results more accurate than PSA



Researchers at the University of Michigan Comprehensive Cancer Center have identified a panel of 22 biomarkers that together provide a more accurate screening for prostate cancer than the current prostate specific antigen, or PSA, test. The study appears in the Sept. 22 issue of the New England Journal of Medicine.

Researchers looked at blood samples taken from 331 prostate cancer patients prior to surgery, and from 159 control males with no history of cancer. They began by testing the samples against a library of 2,300 bacteriophage, organisms that express proteins on their surface, and were able to narrow the field to the 22 biomarkers that most often pinpointed the cancerous blood samples.


More than 230,000 men will be diagnosed with prostate cancer this year. Current screening methods involve a blood test to check for prostate specific antigen, an enzyme produced by the prostate. But the PSA test is controversial. A high level does not always indicate prostate cancer and some experts suggest a rise in PSA is more significant than a consistently high PSA. A high PSA level can also indicate benign prostate conditions.

"Initially, we envision this new test could be used as a supplement to PSA. A physician might suggest a patient with an elevated PSA have this test before a biopsy to better determine whether it’s a cancerous or benign condition. In the future, I think this could replace PSA," says lead study author Arul Chinnaiyan, M.D., Ph.D., the S.P. Hicks Collegiate Professor of Pathology at the U-M Medical School.

In the current study, researchers first tested the blood serum samples of 39 men with prostate cancer and 21 controls to identify autoantibodies against prostate cancer. Cancer patients produce antibodies that fight against proteins that play a role in cancer. The researchers scanned 2,300 autoantibodies and initially narrowed it down to 186 that reacted with blood serum from the men with prostate cancer.

This discovery phase formed the basis for the next round of tests, in which 59 prostate cancer samples and 70 control samples were tested against the 186 autoantibodies. In this phase, the researcher identified a panel of 22 compounds that best distinguished the prostate cancer blood samples from the controls. Using these 22 markers, only two of 70 controls incorrectly tested positive for prostate cancer, and seven of 59 prostate cancer samples were falsely negative.

Next, the researchers validated their findings using the remaining 128 blood serum samples. They found eight of 68 controls and 11 of 60 prostate cancer samples were misclassified. This means 88 percent of the time, samples that were not cancerous were correctly identified and 81.6 percent of the time, samples that were cancerous tested positive.

"These 22 biomarkers appear to be the right number. If you used too many or too few, the accuracy went down a bit. Our findings held up when we tested the model on an independent set of blood serum samples," Chinnaiyan says.

The results proved to be more reliable at predicting cancer than prostate specific antigen, which is a single biomarker. PSA testing results in a false positive around 80 percent of the time, leading to unnecessary prostate biopsies. The normal range for the PSA test is less than 4.0 nanograms per milliliter (ng/mL) in most men. For men over 40 years old with a family history of prostate disease or for African-American men over 40 years old, some doctors suggest that a level higher than 2.5 ng/mL should be checked with more tests, because these two groups of men have an increased risk of prostate cancer.

The 22-biomarker test was reliable at identifying prostate cancer even in the PSA ranges of 4-10 ng/ml or 2.5-10 ng/ml, intermediate PSA scores that do not always suggest cancer. The study authors suggest the 22 biomarkers could be used for patients in this range to help determine whether to undergo a biopsy.

The new test requires only a routine blood draw for patients. Most blood-processing laboratories could easily be equipped to scan for these 22 biomarkers, Chinnaiyan says. Researchers are conducting further studies to validate the findings with a larger, community-based group of patients.

Nicole Fawcett | EurekAlert!
Further information:
http://www.umich.edu
http://www.cancer.med.umich.edu/learn/prostate.htm

More articles from Life Sciences:

nachricht Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>