The test, called the A+PSA assay, also reduced the rate of false-positives, tests that indicate the presence of cancer when no disease is actually present, said Gang Zeng, an associate professor of urology, a Jonsson Cancer Center researcher and senior author of the study.
"This is a very promising new approach," Zeng said. "Instead of using just one parameter, PSA, to test for prostate cancer, we use multiple parameters that can be measured in a single reaction."
The study appears in the May issue of the peer-reviewed Journal of Translational Medicine.
The conventional PSA test for prostate cancer has been used for nearly 30 years and is not specific enough in delineating between malignancies and non-malignant diseases of the prostate, such as benign prostatic hyperplasia (BPH), an enlarging of the prostate common in aging men that increases PSA levels, Zeng said.
The retrospective study used blood taken before surgery from 131 patients from UCLA, Japan and France with biopsy-confirmed prostate cancers and compared results to blood taken from 121 men with either BPH or prostatitis, an infection or inflammation of the prostate that increases PSA levels. The study focused on six specific prostate-cancer associated antigens – NY-ESO-1, SSX-2,4, XAGE-lb, AMACR, p90 and LEDGF - which are found predominantly in patients with prostate cancer and not in benign prostate conditions.
The A+PSA assay looked simultaneously for PSA and antibodies to the six prostate-cancer associated antigens in a single reaction test done in a laboratory, much like PSA is measured. The new test takes about two hours, again similar to the PSA test. The test results in an index of numbers used to diagnose cancer, with a score of 0 to 0.5 indicating a benign result and 0.5 to 1 indicating the presence of prostate cancer, Zeng said.
In the new test, sensitivity - the percentage of men with prostate cancer who were correctly identified as having a malignancy - was 79 percent compared to the 52 percent found in PSA testing. Specificity - the percentage of healthy men who were correctly identified as not having prostate cancer - was 84 percent compared to the 79 percent found when testing for PSA alone.
The rate of false-positives using conventional PSA testing is 21 percent. With the new A+PSA assay, the false-positive rate is 16 percent, Zeng said.
"Science has improved so much since the PSA test was developed and I think it's time for a more specific and sensitive test to be developed," Zeng said. "I think we have a test that has great potential to improve the diagnosis of prostate cancer. I knew it would be better than the classic PSA test, but I was amazed at how much better it really was in this study."
Dr. Allan Pantuck, an associate professor of urology, Jonsson Cancer Center researcher and a study author, said a more specific and sensitive test for prostate cancer would be a welcome addition to the diagnostic tool box.
"While measuring PSA is useful in identifying men with prostate cancer, some men with prostate cancer have a normal PSA level and small elevations in PSA above normal may be produced both by prostate cancer as well as an enlarged but benign prostate," Pantuck said. "Combining PSA with a panel of tests that measure an individual man's anti-cancer immune response may better identify who has prostate cancer and who can be spared an unnecessary invasive biopsy."
Zeng and his team are working now to adjust and improve the statistical index used in their test to generate the "score." He'd like to do a prospective study that would include the racial, ethnic and age information for each man who provides blood. The test could perhaps be altered for men over a certain age if the antibody levels found in their blood vary. African-American men may also have varying levels of the six antibodies. There also are additional antibodies that could be added to the assay that may improve both the sensitivity and specificity of the test, Zeng said.
"Different men may have different levels of the six antibodies or different antibodies all together based on their race, age and ethnicity," Zeng said. "We want as accurate an assay as we can possibly develop."
Any new prostate cancer test would have to be approved by the U.S. Food & Drug Administration.
The study was funded in part by the Prevent Cancer Foundation, the National Institutes of Health and the National Cancer Institute Early Detection Research Network.
UCLA's Jonsson Comprehensive Cancer Center has more than 240 researchers and clinicians engaged in disease research, prevention, detection, control, treatment and education. One of the nation's largest comprehensive cancer centers, the Jonsson center is dedicated to promoting research and translating basic science into leading-edge clinical studies. In July 2010, the Jonsson Cancer Center was named among the top 10 cancer centers nationwide by U.S. News & World Report, a ranking it has held for 10 of the last 11 years. For more information on the Jonsson Cancer Center, visit our website at http://www.cancer.ucla.edu.
Foods of the future
15.08.2018 | Georg-August-Universität Göttingen
New antibody analysis accelerates rational vaccine design
09.08.2018 | Scripps Research Institute
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
15.08.2018 | Physics and Astronomy
15.08.2018 | Earth Sciences
15.08.2018 | Physics and Astronomy