Virginia McMillan
vmcmillan@clear.net.nz
DAILY NEWS: PSA testing may need to be discouraged, an epidemiologist says [image: RCPA]
Epidemiologist Brian Cox is not only promoting caution around PSA screening but also suggests such testing should be discouraged.
Dr Cox says population screening for prostate cancer would be unwise, and suggests PSA (prostate-specific antigen) testing on asymptomatic men should be specialist-ordered only.
Director of the Hugh Adam Cancer Epidemiology unit at Otago University, Dr Cox was commenting on an editorial he wrote with colleague Mary Jane Sneyd in today’s New Zealand Medical Journal.
Dr Cox acknowledges high public concern about prostate cancer and widespread belief that early detection must be good.
Patients being ‘sold a pup’
“If you have had prostate cancer detected and treated, you will naturally believe your life has been saved. But 50 per cent of these people have been ‘sold a pup’,” he says.
The problem is, “we don’t know which 50 per cent”.
Thirty per cent of men aged over 50 have a small tumour in the prostate gland. Under a microscope, these tumours are indistinguishable from cancer but, Dr Cox says, “the vast majority” will never cause symptoms, and may or may not grow.
He also says 50 per cent of men diagnosed via the PSA test would never experience symptoms if left untreated.
Benefits small, if any
Having analysed the two major controlled trials reported in the US and Europe recently, he has concluded that at present, the benefits of PSA testing in asymptomatic men are small, “if they exist at all”.
Even if the at-best 20 per cent mortality reduction suggested by the European randomised study is correct, there are still “major issues” in the harm of over-diagnosis and over-treatment, Dr Cox says.
It’s estimated that 12 to 14 per cent of men who undergo radical prostatectomy develop incontinence and 5 per cent become impotent; 3 to 4 per cent of those undergoing radiotherapy become faecally incontinent and 5 to 10 per cent, impotent.
Screening not only leads to treatment of well men who have no symptoms, it also soaks up resources that could be used on others in the health system, Dr Cox points out.
Although he anticipates opposition to the idea of specialist-ordered PSA tests for asymptomatic men, Dr Cox says it should be considered.
“That’s the only technical way I can see this being manageable.”
Live in the real world
But Peter Foley, chair of the NZMA, says doctors must live in the real world, and public expectations have already been created.
Most men will interact with their GP and he considers this the right place for working through the information on, and uncertainties around, prostate cancer.
Some may decide against getting a PSA test, he says.
Not enough education
Jim Tucker, who blogs about his own prostate surgery and prostate cancer issues says resources must be provided for a public education campaign.
Men often don’t recognise symptoms and need to be encouraged to talk to their doctors about whether tests (PSA and digital) are advisable in their individual case, he says.
The idea of discouraging PSA tests is “extraordinary”, says Mr Tucker.
Minister considering blogger’s letter
He has written to health minister Tony Ryall asking what the Government will do to bring down prostate cancer rates, noted by Mr Ryall earlier this year as a priority.
Jackie Maher, of the minister’s office, says only that the matter is “under consideration”.
Mr Tucker says he was advised of an update to be issued by the health ministry next week.
“There is no imminent announcement on prostate screening,” a ministry spokesperson told New Zealand Doctor today.
source: www.nzdoctor.co.nz
