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Prostate Cancer – New Tests

New prostate cancer tests may replace old PSA test

     The old PSA (prostate specific antigen) test is not only useless and inadequate, but has created countless false alarms resulting in unnecessary biopsies, radiation treatments and unnecessary castrations, either surgically or chemically induced.

Finally there are some new and sophisticated tests that will soon be available to properly diagnose the actual disease known as prostate cancer and to separate those cancers in the prostate from the benign ones that are better left untreated to the aggressive forms that must be treated.

Up until now and elevated PSA number automatically made your physician order a biopsy of the prostate gland. The level of anxiety and fear created by this marginally effective test was great and put fear into the hearts of family and family members. Once a man’s wife hears the word “cancer”, then she feels that every effort must be made to fight this horrible disease.

The problems with the test is that is simply measures the number and size of the prostate specific antigens in the prostate gland and this has very little to do with the actual cancerous cells that may be there. In most cases they will stay there for the duration of a man’s life and not cause his death. Almost every male over the age of seventy has cancerous cells in his prostate gland.

Once diagnosed with a positive result, the majority of men undergo surgery or radiation treatment and many suffer for years, needlessly, from complications such as incontinence and erectile dysfunction.

The number of men who were treated and did not need any intervention was so great that in 2011 the United States Preventive Service Task Force, a government advisory body, provoked a furor by recommending against screening, saying that far more men were harmed by unnecessary biopsies and treatments than were saved from dying of cancer. At around the same time, Dr.Richard Ablin, the creator of the PSA test said that his test was being overused and should only be used as a screening tool for men who already had prostate cancer treatment and not for the general public.

This created a whole area of research to find new and more accurate treatments. Since that announcement more than a dozen companies have introduced tests recently or are in the planning stage in the United States. As a general rule, companies always launch first in the U.S. and then eventually in Canada. This means that if some of these new tests prove to be more accurate and successful at distinguishing real prostate cancer from benign cancerous growths, it may be a while before Canadians will benefit.

Rather than look at a single protein such as prostate specific antigen in the old PSA test, these new tests used advanced techniques to measure multiple genes and many other so-called molecular markers.

The new science of molecular markers is being done by Dr. Douglas Dolginow, chief executive of GenomeDx Bioscience, a startup that feels its test will be extremely accurate and out on the market within the next two years.

Of course once these tests come onto the market there will be a great deal of competition and each one will claim to get the best results.  The biggest of these competitions will be between Genomic Health and Myriad Genetics, which are both moving into the prostate cancer field after successes in breast cancer testing.

Myriad is known for its test for genetic mutations that raise the risk of getting breast cancer. Genomic Health’s Oncotype DX test helps determine if a women should receive chemotherapy and which drugs will work depending on the specific genetic mutation that she has.

Since the report came out recommending against the PSA test, prostate screening has declined quite a bit in the U.S. However millions still get the test and every year as many as one million men undergo biopsies with about 240,000 prostate cancers diagnosed and 28,000 deaths annually from the disease. In Canada we see about 27,000 new cases each year and the death rate is about 2900. This means that the market can be increased with new and accurate tests and more lives can be saved, and needless treatment will spare even more men from being castrated or even dying from the procedures.

Both companies have developed tests in which they analyze gene activity levels in the tumour sample obtained in the biopsy to determine how aggressive the cancer actually is. This helps doctors and patients make a more informed decision about whether to treat it.

Because the PSA test is so inaccurate, it is also possible to err in the other direction. In one such case, a patient had what is called a low Gleason score and low PSA levels and yet the new test done by Myriad’s Polaris showed that the tumour was aggressive and the patient required surgery. The Gleason score is based on the appearance of the cancerous tissue and the more abnormal it looks the higher the Gleason number.

Some excellent research into these new tests is being done by Dr. Eric A. Klein at the Cleveland Clinic with funding from Genomic Health and by Dr.William J.Catalona, director of the prostate program at Northwestern University, the man who helped bring the PSA test to the market in the 1990’s.

Hopefully in the near future we will have very accurate tests to determine not only the presence of different types and sub-types of prostate cancer but which ones are actually aggressive and need treatment.



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