Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Prostate cancer screening practices examined

16.03.2005


Initial results from an ongoing study evaluating the benefit of prostate cancer screening practices demonstrate that the combined use of both standard tests--the prostate-specific antigen (PSA) blood test and the digital rectal exam (DRE)--is optimal for detecting cancer.



The initial results also confirm that the design of the massive study, which will continue until 2019, will indeed allow researchers to determine whether current screening practices reduce death from prostate cancer, according to the authors. They present their analyses in two papers, one in the March 16 issue of the Journal of the National Cancer Institute and the other in the March issue of the Journal of Urology.

The study is part of the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial being conducted by researchers at Washington University School of Medicine in St. Louis and several other institutions.


Uncertainty about the need for prostate cancer screens stems from several factors. PSA and DRE tests can be inaccurate, giving both false negatives and false positives. In addition, neither test indicates how aggressive a man’s cancer is. Furthermore, because prostate cancers grow slowly in many cases and treatments can have unpleasant side effects, treating the cancer may be less desirable than leaving it alone, especially in older men.

"But the main thing is we don’t know whether screening saves lives," says Gerald L. Andriole Jr., M.D., head of the Division of Urologic Surgery at Washington University and Barnes-Jewish Hospital. "Our study follows about 75,000 men, half of whom we are screening, and half of whom are getting conventional care. By comparing groups over the long term, we will see what difference screening makes in survival rates."

Begun in 1993, the PLCO study has screened 34,244 men across the United States, aged 55 to 74, for prostate cancer and followed their subsequent medical history. The PLCO protocol advises men to consult their own physician if either the PSA or DRE tests given by PLCO are suggestive of cancerous growth.

The outcome of the study should aid patients and doctors in making decisions about diagnosis and treatment of prostate cancer. "It’s a complex decision," Andriole explains. "Say your father had an abnormal PSA test, and he’s 76 and has a bad heart, diabetes, or recently had a stroke. Frankly, the patient and doctor have to base their decision on the probability that one of those factors may cause death before prostate cancer."

Of the men screened by PLCO, about 14 percent had positive screening results, indicative of possible cancer. Approximately 8 percent screened positive by PSA test, and about 7 percent screened positive by DRE test. Only about 1 percent of these results overlapped, demonstrating the importance of using both screening methods.

"We were hopeful some years ago that men could just have the PSA blood test, because men hate the rectal exam," Andriole says. "We’ve found that if you omit the DRE, you’ll miss a certain percentage of cancers."

Three-fourths of the men with positive PLCO screens went in for further diagnostic evaluation with their personal physician. The physicians would decide whether to conduct their own screenings and whether to subsequently perform a biopsy, which is needed to confirm the presence of cancer before treatment.

About a third of men with abnormal tests had a prostatic biopsy within a year of the initial screen. Of men with PSA readings higher than normal, 64 percent underwent biopsy within three years. The higher the PSA readings, the higher the biopsy rates. The biopsy rate in men with positive DRE alone was 28 percent.

The initial data indicate that younger men, men with a family history of prostate cancer and African American men are more likely to have a biopsy after an abnormal screening result. "These statistics parallel many medical recommendations and reassure us that good judgment is being applied to the evaluation of the initial screen," Andriole says. "We are confident that when the study is ultimately completed, it will truly measure the effect of current medical practices."

In men with suspicious PSA readings, regardless of DRE findings, biopsy revealed cancer almost half the time, while in men with suspicious DRE tests, regardless of PSA levels, biopsy found cancer about a third of the time.

The majority of men with cancer had localized cancers. About ten percent had more serious advanced forms. These advanced cancers were linked to higher PSA numbers and suspicious DRE results.

Overall, 1.4 percent of the approximately 34,000 men screened were subsequently diagnosed with prostate cancer by tissue biopsy. This rate of detection is lower than in two previous studies of prostate cancer screening, which found cancer in 4.2 and 3.2 percent of patients, respectively.

This lower rate of detection more accurately reflects the contemporary standards of practice, because biopsy and diagnosis took place outside of the PLCO study, according to the authors.

Gwen Ericson | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Health and Medicine:

nachricht Cardiac diseases: when less is more
30.03.2017 | Universitätsspital Bern

nachricht TSRI researchers develop new method to 'fingerprint' HIV
29.03.2017 | Scripps Research Institute

All articles from Health and Medicine >>>

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

NASA laser communications to provide Orion faster connections

30.03.2017 | Physics and Astronomy

Reusable carbon nanotubes could be the water filter of the future, says RIT study

30.03.2017 | Studies and Analyses

Unique genome architectures after fertilisation in single-cell embryos

30.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>