Movember moustaches may help find new prostate cancer tests
Breakthroughs expected in the search for an alternative to PSA testing
Money raised through past Movember men's health campaigns is helping fund the search for alternatives to PSA screening for prostate cancer.
That search has taken on added importance now that an official task force has recommended not using PSA testing to screen for prostate cancer.
Prostate-specific antigen — or PSA — testing measures the amount of that protein enzyme in blood. Higher levels may indicate the presence of cancer or infection in the prostate. Or sometimes they may not.
The test costs an individual about $30. In B.C., the province covers the costs, andits billed about $11.
Prostate cancer is the most common cancer in men (excluding the skin cancers) and ranks third in number of deaths, after lung and colorectal cancer.
While the recommendations by the Task Force on Preventive Health Care don't mean the end of PSA testing — they are opposed by groups like Prostate Cancer Canada and the Canadian Cancer Survivor Network — efforts to develop other diagnostic tools are well underway.
For Stuart Edmonds of Prostate Cancer Canada, "PSA isn't the bad actor in this, it's actually decision-making along the process that's part of the problem, how the PSA is being interpreted or how men are being pushed or choosing to have treatment when actually treatment may not be necessary."
And Jackie Manthorne, the Canadian Cancer Survivor Network's president and CEO, says: "Don't throw PSA tests out the window until we have something viable to replace it with.”
- PSA test should be abandoned as screen for prostate cancer, task force says
- Backgrounder on PSA testing
This year, Edmonds' organization has already directed Movember Foundation-funded grants worth $10 million toward research on alternative diagnostic tools for prostate cancer. The Movember campaign, best known for the moustaches grown to raise awareness about men's health issues, starts today.
Spending on all prostate cancer research in Canada totalled more than $36 million in 2011, according to the Canadian Cancer Research Alliance.
Diagnosing prostate cancer with DREs and MRIs
At present, besides the PSA test, the only other widely used diagnostic technique is the digital rectal exam, or DRE. The DRE can only be done on the back of the prostate gland, although that's the site of 85 per cent of prostate cancers.
During the DRE, the doctor is feeling for lumps or hardened areas, which, if caused by cancer, mean the disease is more advanced.
Edmonds says the DRE certainly has some value but notes, "current screening studies do not consider DRE in addition to PSA screening."
Men have been diagnosed with prostate cancer by a DRE, he notes, which is then confirmed by a biopsy.
Testing is also underway to show how effective magnetic resonance imaging, MRI, can be for detecting prostate cancer, Edmonds says.
A research article published by the medical journal The Lancet in August says, "A promising approach lies in the development of multiparametric MRI imaging technology of the prostate, which at present claims to selectively diagnose aggressive prostate cancers and avoid the diagnosis of many non-significant cancers."
If it happens, the price tag will likely be high. However, distinguishing between cancers that can kill and ones that men can live with is critically important when deciding treatment.
"Overdiagnosis occurs in roughly 40 per cent of cases detected by screening," according to The Lancet article.
Cutting edge research
One of those Movember grants gives $5 million to a cross-Canada team for research to better identify "men who do or do not need aggressive treatment by providing accurate information about risk at diagnosis," and to "develop novel molecular diagnostic tests to predict which men are likely to develop aggressive cancer," says Prostate Cancer Canada.
The team is led by John Bartlett of the Ontario Institute of Cancer Research.
A smaller grant went to a team headed by Dr. John Lewis at the University of Alberta. Its goal is to develop tests that look at a particular protein to predict the outcome of a prostate cancer when it's diagnosed.
"These tests could tell us if the patient is at high risk for developing aggressive metastatic disease or if that patient’s disease is in a benign state," Lewis says.
Lewis says they hope to have an initial clinical test within three years and a blood test in less than 10 years.
New diagnostic tests
Two other Movember grants in Canada are going to research on biomarkers that may lead to a new test to diagnose prostate cancer.
Robert Day at the University of Sherbrooke is looking at developing a diagnostic test that Prostate Cancer Canada says could "complement or even replace PSA."
Their research will focus on an enzyme Day's team discovered, sPACE4, that shows up at abnormally high levels with prostate cancer and can be correlated with the severity of the tumour.
A team from the University Health Network in Toronto, under Bharati Bapat, has a grant to develop a DNA-based biomarker test that can predict if a patient has an agressive prostate cancer.
They are studying genes called microRNAs found in a patient's urine, for example, and comparing them to the patient's symptoms, etc.
They hope that could lead to a test that can predict if a man has prostate cancer and how aggressive it will be.
Edmonds says genetic testing "is one of the areas where there are likely to be big breakthroughs in the future."
Meanwhile, Mats Daugaard at the Vancouver Prostate Centre is researching a sugar structure, CSA, that is found at high levels when prostate cancer is present.
Daugaard says he is very optimistic his research will lead to "making diagnosis more accurate and making it, possibly, earlier."
He says studying the sugar could also lead to better therapy to target the cancer. His research grant comes from funds donated at Safeway stores.
These poppy-seed-sized stones, mostly consisting of calcium phosphate, have been found in almost all surgically removed prostate glands.
But now, scientists with the Centre National de la Recherche Scientifique and Tenon Hospital in France have found that with infrared spectroscopy and scanning electron microscopy, they can determine whether there is or has been an infection of the prostate, even asymptomatic infections.
This is potentially important because scientists have linked infection-related inflammation with cancer of the prostate, as well as other organs.
To apply this knowledge to diagnosis, Dominique Bazin, research director at the CNRC, says doctors could find the stones with a CT scan. If present, that should "trigger an investigation by doctors," Bazin told CBC News.
Bazin said his team recently used the same techniques to examine small calcium deposits in breast tissue and says the initial findings, not yet released, are "quite exciting" for early detection of breast cancer.