Men with prostate cancer are being given false hope by tests that underestimate the aggressiveness of their disease, a study suggests.
Researchers found that more than half of a group of men whose cancers were initially classified as slow-growing and confined turned out to have more dangerous tumours.
The findings, published in the British Journal Of Cancer, call into question the ability of experts to grade and stage prostate cancers on the basis of biopsy samples.
It also casts doubt on the "active surveillance" strategy of avoiding unnecessary radical treatment for patients with slow-growing prostate cancer.
Instead, these patients are often closely monitored but left alone until tests suggest their condition has worsened.
In order to develop a new DNA test that can identify men at high risk of recurring prostate cancer, scientists analysed biopsy tissue samples taken from 126 treated men with the disease who were thought to be at intermediate risk of their cancer returning.
- Researchers then looked at each patient's whole genetic code, searching for missing, extra, or irregular sections of DNA so they could identify signature patterns linked to a high or low risk of recurring cancer
- The test was used to predict outcomes for a second group of 150 patients who had their prostate tumours removed by surgery.
- A secondary study found that tumours affected by hypoxia - starved of oxygen - were most associated with worse survival
- Men with low levels of genetic changes and low hypoxia had the best outcomes, with 93% lasting five years without their cancer recurring
- Only 49% of men with high levels of genetic alterations and high hypoxia escaped a cancer recurrence for five years.
A new DNA test can identify men at high risk of recurring prostate cancer with almost 80% accuracy, say scientists.
The biopsy test singles out patients likely to relapse after surgery or radiotherapy by looking for specific genetic changes at 100 sites in DNA.
Researchers from the University of Toronto, Canada, believe the "genetic signature" test will help doctors determine which patients need extra help after initial treatment.
Professor Robert Bristow, lead scientist, said: "Existing methods for identifying high risk patients are imperfect, so new tests are required that are better at predicting which patients will have their cancer recur.
"These men can then be offered additional treatments, such as chemo and hormone therapy, that will combat the prostate cancer throughout their entire body, rather than therapies solely focused on the prostate, in order to improve their chances of survival.
"This is the first report of a test using information derived from biopsy samples that can predict with close to 80% accuracy which men are at high or low risk of their prostate cancer recurring."
Vitamin E and selenium pills are putting men at significantly increased risk of prostate cancer, a group of US scientists has warned in findings published in the Journal of the National Cancer Institute.
These supplements are popular - especially vitamin E - although so far no large, well-designed and well-conducted study has shown any benefits for preventing major chronic disease.
Men using these supplements should stop, period. Neither selenium nor vitamin E supplementation confers any known benefits, only risks...
We know from several other studies that some high-dose dietary supplements - that is, supplements that provide far more than the daily recommended intakes of micronutrients - increase cancer risk.
Men have been warned not to take a pair of popular vitamin and mineral supplements after research showed they can dramatically increase the risk of life-threatening prostate cancer.
Overdosing on the mineral selenium by taking supplements raises the chances of developing high-grade cancer by 91%, US scientists have found.
Vitamin E pills also boosted the risk of aggressive cancer, more than doubling it for men lacking selenium, according to researchers from the Fred Hutchinson Cancer Research Centre in Seattle.
The researchers believe selenium can turn toxic when present in the body at excessively high levels.
Nice's decision to withhold a breakthrough prostate cancer drug is a "cruel twist" as it comes "just days" after a study confirmed its success, campaigners have said.
Prostate Cancer UK called on Nice, who vet the cost effectiveness of medicine for NHS patients, to change its "post-chemo" policy on new drugs.
Enzalutamide is already licensed for those who've had chemotherapy but this trial will hopefully establish a robust base of evidence to demonstrate that it should be available beforehand.
This is good news but sadly won't help the one man an hour who dies of prostate cancer at present.
We need to see drugs like enzalutamide available sooner rather than later, and so it's a cruel twist that this study comes just days after Nice ruled out the drug for men who have already had chemotherapy and the only other drug available at this stage, abiraterone.
A lack of evidence is behind the NHS' decision to withhold a breakthrough prostate cancer drug from patients who have already been treated using another new generation drug, Nice said.
A spokeswoman for Nice said the committee were unable to "draw any conclusions" about what would happen if "milestone" enzalutamide was used by prostate cancer sufferers who had also taken abiraterone.
In the trial data provided by the manufacturer of enzalutamide none of the patients had received previous treatment with abiraterone, therefore the committee was not able to draw any conclusions about the effectiveness of enzalutamide after previous abiraterone treatment, and this is reflected in the recommendations.
We would welcome any additional data the manufacturer of enzalutamide can provide.
Prostate cancer medicine hailed as a "milestone" breakthrough may not be available to every patient after a revision of the drug guidelines, according to the NHS.
Men in England who have already been treated with a new-generation cancer drug would not be eligible for Enzalutamide, according to the National Institute for Health and Care Excellence (Nice).
Nice, the public body which decides the cost-effectiveness of medicines for NHS patients, said the new drug should not be used by patients who had already taken abiraterone.
Enzalutamide blocks molecular signals driving prostate cancer and improved survival by 30% in men who had not undergone chemotherapy.
A further 80% of men with advanced cancer had the progression delayed, even if the tumour had failed to respond to other treatments.
With men often finding it easier to talk tactics than testes, the comedian issues an open invitation to join a star-studded squad.Read the full story ›
Prostate cancer will become the most common cancer in the UK "in the next 15-20 years".
"All the statistics say that prostate cancer is currently the most common cancer among men, it's about as common as breast cancer. Within the next 15-20 years it will be the most common cancer in this country.
"For the majority of the men who have it, they don't have any symptoms. That is the very reason why you need to go to the doctor, particularly when you get close to 50 and see if the test is right for you."