Routine screening for cancer of the prostate could do more harm than good, suggests David Nolan
Hands off our glands
Cancer of the prostate - a chestnut sized gland above the bladder - is a nasty business. It affects one in 12 men, and killed 8782 of us in 1996. Thanks to a screening test developed in the 1980s, it is now possible to stop the cancer in its tracks. Prominent doctors, politicians and charities are pressing the Department of Health to advocate routine screening for the disease.
But would routine screening necessarily be a good thing for men?
PSA (prostate-specific antigen) screening is currently available in the UK but not routinely used. These blood tests give an indication of whether some symptoms, such as tiredness, indigestion and urinary problems, are caused by cancer of the prostate. And unlike its predecessor, a digital rectal examination which was accurate in only about 20-30 per cent of cases, PSA works. Before testing was introduced in the USA, 60 per cent of prostate cancer cases had spread so far by the time they were detected as to become essentially incurable. Patients faced a choice between hormone therapy and removal of the testes. Now the same percentage of detected cancers are confined to the gland and can be eradicated by surgery or radiation.
Not surprisingly, the success of this new test compared with the old has attracted many fans. But there are also many problems associated with PSA screening tests, and in some cases it is better to let the disease run its course.
The PSA test provides many false positive readings due to the more common problem of non-cancerous benign prostatic hyperplasia (BPH). PSA is produced by all types of prostate tissue: normal, hyperplastic, and malignant. BPH - enlargement of the prostate - affects one in three men in their fifties and up to 90 per cent of men in their eighties and nineties, and can have the same symptoms as malignant tumours. BPH is uncomfortable but not life threatening, and false positive readings cause unnecessary worry among many men and their families.
Studies have shown that most growths of cancer in the prostate do not lead to serious illness or death. A third of men over age 50 experience some form of the cancer, but only about 4 per cent will develop clinical cancer and only about 1.2 per cent eventually die of it. In many cases among older men it will be a matter of chance as to which disease gets you first, and often the disease is only diagnosed after death.
Over-treatment is a potential minefield when the treatment proves to be worse than the disease itself. Some hormone treatments result in menopause-type symptoms and breast swelling. Removal of the source of the testosterone which feeds the cancer - the testes - is often unacceptable to men and can result in impotence and penile dysfunction. Other side-effects may be unbearable, such as several months of urinary stress incontinence (permanent in 3-5 per cent of cases) and six months to a year of impotence (permanent in 30-50 per cent of cases). Treatment can involve the insertion of a catheter into the penis for a year, which causes immense discomfort. A father of a friend of mine swore he would have preferred not to have had the treatment - before he died of something else a couple of years afterwards.
As Dr Gerald Chodak of the University of Chicago explained in a pre-screening handout, 'many more men will have small, slow-growing prostate cancers than deadly ones'. There is no benefit in treating 'harmless' cancers, but there is no sure way of telling these cancers from the harmful ones before surgery. So, he argues, 'we would cause more harm in treating 10 men, whose cancer would never have hurt them, than we would prevent, in curing one of those whose would have'.
Given all the problems associated with PSA tests, why have campaigners made such a big deal of calling for routine screening? Not so much because men feel that their health is under threat from prostate cancer as that they feel their healthcare is under threat - from women.
It was perhaps no coincidence that in the UK the calls for screening peaked in October which was also national 'Breast Awareness Month'. In the USA Bob Dole, a leading proponent of screening is honorary co-chairman of US TOO, a national support group for prostate-cancer survivors which demands that men's health issues be given as much attention as women's. The Canadian Prostate Cancer Foundation issued an angrily-worded press release earlier this year making a comparison between the 'less than $500 000' dedicated to prostate cancer research in 1996, 'while over $17 million was spent on breast cancer research'.
In the UK, Maxim magazine carried out a survey of 'men near the Millennium' which showed that almost 90 per cent wanted men's health issues to be given the same priority as women's. It also pointed out that the Cancer Research Campaign spent over £10 million on breast cancer research and awareness and only £1.5 million on prostate cancer. The government-sponsored Medical Research Council spends about a tenth as much on prostate research as it does on breast cancer.
There is no harm in advocating research. But when there are clear suggestions that routine screening might cause more harm than good, there is something rather sad about campaigns to make the government advocate it just because the government advocates screening for breast cancer. It seems to have more to do with men whinging about their own vulnerability than about doing something to increase their chances of detecting cancer.
In a recent article in the European Journal of Urology Professor Reg Hall, from the Freeman Hospital in Newcastle, said of the widespread use of PSA tests in the USA that 'European men deserve the benefit of scientifically based information before being exposed to another North American fashion' (1996, Vol29, pp24-36). Unfortunately, European men are already exposed to the 'North American fashion' of being obsessed with their health. When this means volunteering to walk around with a catheter in your penis just so you can have the same claim on medical resources as the girls, we should start worrying.
Reproduced from LM issue 106, December 1997/January 1998