An international cancer specialist has devised a novel way of reducing the burden from one of Britain's fastest rising malignant diseases: diagnose it less. Chris Parker, a world authority on prostate cancer at London's Royal Marsden Hospital, says that the diagnosis does more harm than good in many men.
Prostate cancer cases have tripled since the 1970s and the annual "toll" of 40,000 cases diagnosed in the UK could be cut by more than 10,000, he says.
Advances in understanding of the disease during the past decade have enabled doctors to distinguish men with high-risk, aggressive disease, which needs treatment, from those with low-risk, slow-growing disease, which does not. Low-risk men are more likely to die with the cancer, as a result of some other cause, than from it.
But that means they gain no benefit by being diagnosed – and suffer harm because they live for the rest of their lives under the shadow of cancer.
Writing in the British Medical Journal, Dr Parker says: "The standard of care for low-risk prostate cancer should be watchful waiting [regular monitoring], which raises an important question: if low-risk prostate cancer does not need treatment, then does it need to be diagnosed at all? In future, we need to focus on avoiding not just the treatment, but also the diagnosis of low-risk disease."
Dr Parker, consultant clinical oncologist in the Academic Urology Unit at the Royal Marsden and the Institute of Cancer Research, was commenting on the results of the largest trial of prostate cancer surgery in the world, revealed by The Independent in April and published last month in the New England Journal of Medicine. It showed that surgery for low- to medium-risk prostate cancer was useless.
Patients in the Prostate Intervention versus Observation Trial (Pivot) who had the standard operation to remove the prostate gland, called a radical prostatectomy, did not survive longer than those who had no treatment.
In the UK, six out of 10 men diagnosed with low-risk prostate cancer have immediate treatment, according to the British Association of Urological Surgeons.
"Thus the current practice of treating low-risk disease with radical prostatectomy is at odds with the best available evidence now provided by Pivot – that surgery for low-risk prostate cancer is not effective," Dr Parker writes.
That leaves the question of how men should be diagnosed. Dr Parker said the PSA blood test could still be used to screen for cancer in men with symptoms but other factors should be taken into account and more sophisticated tests used. The symptoms of prostate cancer include difficulty urinating, urinating more than usual, especially at night, hesitancy or a weak stream.
"We want to get away from sole reliance on the PSA test and move to a risk-based calculation that includes the PSA plus age, family history, size of prostate and other measures. We also want to find new and better ways of estimating risk such as using MRI scans in the same way as mammography is used for breast screening," he said.
"If shown to be successful, such an approach could cut the annual incidence of prostate cancer by more than 10,000 and save time, costs and the emotional distress associated with deciding how to treat low-risk disease."
Professor Mark Emberton, consultant oncologist and specialist in urology at University College Hospital, London, said MRI scans should be used to diagnose cases.
Prostate cancer by numbers
40,000 The number of cases of prostate cancer that are diagnosed in the UK each year.
x3 Newly diagnosed cases have tripled since the 1970s.
10,000 The amount of new cases could be cut by this amount if doctors avoided diagnosing men with low risk disease.
10,000 Deaths from the disease in 2010.
80% Can survive for more than 5 years.
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