If they're right, the protein – an enzyme called human aspartyl (asparaginyl) beta-hydroxylase, or HAAH – could ultimately help reduce the number of unnecessary biopsies for prostate cancer and may identify cancer at an earlier stage when treatment would have a higher likelihood of success.
Prostate cancer is expected to account for more than 234,000 new cases and about 27,000 deaths in the United States in 2006. The American Cancer Society recommends that all men over 50 be screened annually with two standard tests: the prostate specific antigen, or PSA, which measures a protein in the blood, and the digital rectal exam, or DRE, which entails a physical exam the prostate.
Yet the PSA and DRE can be inexact and, at times, not specific or sensitive to cancer. High PSA levels are found in both cancerous and healthy tissue, particularly in benign prostate disease, resulting in significant numbers of false positive cases. The DRE, based on physician touch and skill, relies on subjective judgment. As a result, a man who has prostate cancer can have both a normal PSA and DRE. Conversely, an individual with a high PSA and an abnormal DRE could be cancer-free.
"There is a great need for a test that increases the sensitivity and specificity of those two other tests for prostate cancer," said Stephen Keith, M.D., M.S.P.H., president and chief operating officer of Panacea Pharmaceuticals, Inc., Gaithersburg, MD.
Results were presented at the first meeting on Molecular Diagnostics in Cancer Therapeutic Development, organized by the American Association for Cancer Research.
"Currently, if an individual has a high PSA and positive DRE, the recommendation is that he has a biopsy of the prostate, and more often than not – by some estimates, as much as 80 percent of the time – there will not be evidence of cancer," Dr. Keith said.
Yet, biopsies can be painful, expensive and difficult to perform, and may cause a high number of infections, noted Hossein Ghanbari, Ph.D., chief executive officer and chief scientific officer at Panacea.
According to Ghanbari, HAAH is overexpressed in at least 20 types of cancer tested to date, including liver, breast, ovarian, colon, esophageal, and prostate. It has been shown to be involved in tumor growth, invasiveness and cancer spread.
The researchers previously examined tissue from more than 20 different cancer types and compared them to more than 1,000 normal tissue types. Using immunohistochemistry techniques, they found that more than 99 percent of cancers were positive for HAAH. None of the normal issue samples were positive.
To find a more accurate way to detect prostate cancer, Ghanbari and his co-workers at Panacea developed a test in which they could detect HAAH in blood serum.
In the current work, Ghanbari and his co-workers compared HAAH levels in the blood of 16 individuals with prostate cancer to 23 healthy individuals. Those with prostate cancer showed high HAAH levels, whereas none of the normal control individuals did.
"We've learned that HAAH is generally detected in prostate cancer and not in normal prostate tissue, in addition to a number of other cancers," he said.
The scientists foresee the HAAH test used in conjunction with DRE and PSA testing. "We hope our HAAH blood test combined with PSA and DRE will increase the sensitivity and specificity of screening for prostate cancer," said Keith. "Those without cancer can avoid unnecessary biopsies through the use of all three screening tests."
"Having a positive DRE and high PSA, the HAAH would put the final stamp of approval," Ghanbari said.
Panacea scientists are planning clinical trials with prostate tissue samples from 800 patients, including 400 men with prostate cancer and 400 healthy individuals.
"The goal is to be able to take someone with increasing PSA numbers and a positive DRE, measure the HAAH level and look at biopsy results," Ghanbari said, "and be confident that HAAH provides the additional benefit in terms of specificity and sensitivity. The addition of HAAH should improve the prediction of who will have positive biopsy results for prostate cancer."
Warren Froelich | EurekAlert!
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
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...
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...
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...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
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...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy