Half of prostate cancer cases may be missed
Half of prostate cancer cases may wrongly be given the all clear due to flaws in diagnosis procedures, a new study has found.Experts say that thousands of patients are being put at unnecessary risk because most NHS hospitals are using outdated and inaccurate techniques.
Prostate cancer is the most common cancer in men, affecting 40,000 people a year and causing 10,000 deaths. One in eight men will develop the disease within their lifetime.
The study by the London School of Hygiene and Tropical Medicine and University College London suggests that as many as half of cases where patients have “significant” levels of prostate cancer could be being missed during standard biopsy procedures.
Thousands more men may be wrongly diagnosed as having cancer which requires major treatment, such as surgery or radiotherapy, the researchers found.
In most British hospitals, men with suspected prostate cancer automatically undergo a biopsy to remove and examine tissue in an attempt to establish whether disease is present.
However, research has suggested that diagnosis is far more accurate if patients undergo an MRI scan first, to examine the area, with the findings mapped via ultrasound, so that the needle can be guided and tissues taken from precisely where a tumour is suspected.
In the new study, health economists calculated that the use of the modern technique could mean that one quarter of men with suspected prostate cancer could be given the all-clear without even undergoing the invasive diagnostic procedure.
For every 1,000 men with suspected cancer, around 250 men could have been reassured simply by undergoing a scan, they said.
Of around 500 of the cases in which significant disease was present, just 50 per cent were detected during the traditional biopsy, compared with 68 per cent detection rates using the MRI-guided technique, the study found.
One in 20 of those undergoing the traditional biopsy were wrongly found to have significant disease levels –meaning they would be likely to undergo unnecessary aggressive treatment, such as surgery, radiotherapy or hormone treatment, with distressing side effects including incontinence and impotence.
Using the MRI-guided technique, around half as many men were wrongly given a diagnosis of significant disease.
The vast majority of prostate cancer cases occur in men over the age of 65. Lung cancer is the only cancer which kills more men.
Symptoms can include needing to urinate frequently and difficulty urinating, but this is also common in older men without the disease.
Currently, more than 100,000 biopsies a year are carried out on men with suspected prostate cancer and 40,000 men are diagnosed with the disease.
If the cancer is found at its early stages, doctors are likely to monitor its progress, but nearly 4,000 men a year undergo surgery, while 15,000 undergo radiotherapy or hormone treatment.
Prof Mark Emberton, professor of interventional oncology at University College London, lead investigator on the study, funded by the Wellcome trust, called on hospitals to update their practice.
Prof Emberton, a consultant urologist at University College Hospital, London, uses the MRI technique for all patients with suspected prostate cancer, but the vast majority of hospitals in this country still carry out traditional biopsies, with little idea of which area to target.
He said: “There is no other organ of the body where we carry out random ‘blind’ biopsies without knowing where we are looking – at UCLH we have been using MRI, followed by a guided biopsy for several years, but there are only a handful of hospitals in this country which currently do this, and that needs to change.”