October 9, 2012
‘Barcode’ Blood Test Reads Genetic Results, Helps Detect Aggressive Prostate Cancer
Lawrence LeBlond for redOrbit.com - Your Universe Online
A blood test that can read genetic results much like a ℠barcode´ has been developed by scientists at the Institute of Cancer Research (ICR) and the Royal Marsden NHS Foundation. This genetic blood test can also detect the most aggressive prostate cancers by reading particular patterns of gene activity.
Research staff believe the test could eventually be used to select patients who are most in need of immediate treatment. Prostate cancer is a very diverse disease. Some people live with it for years without any symptoms, but in others, the disease can be very aggressive and life-threatening, said lead author of the study, Professor Johann de Bono, of ICR, and an honorary consultant at Royal Marsden.
Current cancer screening tests include a biopsy, where doctors take a small sample of a tumor and examine it under a microscope to find out how dangerous it may be. Experts hope that the new barcode test will ultimately lead to more accurate estimations without invasive biopsy screenings. The researchers also believe the barcode test could be used in conjunction with current PSA screenings to select patients who are in dire need of treatment.
Described in The Lancet Oncology medical journal, the test is unique because it can assess changes in the pattern of gene activity in blood cells triggered by a tumor found elsewhere in the body.
“We've shown it is possible to learn more about prostate cancers by the signs they leave in the blood, allowing us to develop a test that is potentially more accurate than those available now and easier for patients than taking a biopsy. Our test reads the pattern of genetic activity like a barcode, picking up signs that a patient is likely to have a more aggressive cancer. Doctors should then be able to adjust the treatment they give accordingly,” said de Bono.
In the trial, de Bono and colleagues scanned all the genes present in blood samples of 100 patients with prostate cancer at the Drug Development Unit in London and The Beatson West of Scotland Cancer Centre in Glasgow. The trial included 69 patients with advanced prostate cancer and 31 control patients with low-risk, early-stage cancer.
The team divided the patients into four groups reflecting their pattern of gene activity--the barcode. After reviewing all the patients´ progress over nearly 30 months, the researchers found patients in one group had survived for significantly less time than patients in others. Further modeling identified nine key active genes shared by all patients in the group.
The researchers then compared the results with another group of 70 US patients with advanced cancer. What they found is that these nine genes could be used to accurately identify those who survived for a shorter period--9.2 months compared with 21.6 months for patients without the gene pattern. The findings suggest a number of the genes actually suppressed the immune system in patients whose cancers were spreading.
“Whether particular genes are active or not is an important clue in identifying patients with a poor prognosis. This latest study shows that it is possible to read these patterns of gene activity like a barcode, allowing scientists to spot cancers that are likely to be more aggressive,” said Professor Alan Ashworth, chief executive of The Institute of Cancer Research.
“Personalized medicine is the future of cancer treatment. This blood test, which reads genetic changes in prostate cancer providing a prediction of how aggressive the cancer might be, is an important development, allowing us to better tailor treatment to suit each individual,” added Professor Martin Gore, medical director at The Royal Marsden.
“For years it has been extremely difficult to try to predict which men have very aggressive tumors and which do not,” noted Dr. Kate Holmes, head of research at Prostate Cancer UK. “We are therefore encouraged by news of research, part funded by Prostate Cancer UK, that may have taken a step towards finding a test that can finally draw this distinction.”
“If these early findings can be confirmed by much larger studies over time this method could potentially be used to help inform how aggressive a tumor will be and empower men and their clinicians to make much more informed decisions about which treatments are best for their individual circumstances,” Holmes said in a statement, reports Mail Online´s Jenny Hope.
“We look forward to seeing the results of further research and hope it confirms the findings hinted at today,” she said.
A similar six-gene prostate cancer blood test, currently being tested by researchers at the Dana-Faber Cancer Institute and the Memorial Sloan-Kettering Cancer Center, can split patients into high and low risk groups.
“Not only do they point to a group of patients with advanced prostate cancer who do particularly badly, and who therefore may need different forms of treatment, but they also point to the possible role of the immune system in influencing how a cancer might behave,” he said. “If the present results are borne out in further studies, we may have a new way of selecting the right treatments for the right patients.”
Prostate cancer is the most common male cancer in the UK, with more than 40,000 diagnoses every year. More than 10,000 men die from the disease each year as well.
The ICR/Royal Marsden study was funded by AstraZeneca, Prostate Cancer UK and the Prostate Cancer Foundation. The Drug Development Unit receives funding from Cancer Research UK and the Experimental Cancer Medicine Centre network.