Prostate Cancer

  • show transcript
Monday 17 March 2003 12:00AM (view full episode)

Swedish researchers have looked at the quality of life of people who have been diagnosed with prostate cancer. They have followed men who either decided to have surgery or opted for watchful waiting.

Plus PSA screening for prostate cancer. Researchers in Sydney conducted a trial to find out if evidence-based information about prostate cancer screening enhances consumer decision making.

And the connection between an unhealthy lifestyle and your chance of getting prostate cancer. The incidence of prostate cancer in western men is much higher than that in Asian men. Researchers in California think that differences in diet and exercise might have a lot to do with it.


What's also very Scandinavian is Sweden's incredible advantage over countries like Australia when it comes to looking at the results of cancer treatment. They have amazing systems which track people with cancer through the health system to see how they fare; not just survival, but quality of life.

Gunnar Steineck and his colleagues have done this following men with prostate cancer who either decided to have treatment, a radical prostatectomy, or watchful waiting, waiting to see what happens.

Gunnar Steineck: Yes. When you survive, the next question is do I have a life after having survived cancer? Before this study there was a feeling that you could improve survival by operating, but with a cost of a decreased quality of life.

Norman Swan: It was erectile dysfunction, incontinence.

Gunnar Steineck: Erectile dysfunction, incontinence comes immediately after, but it turned out that these immediate symptoms were balanced by a large array of other factors, and self-assessed quality of life and wellbeing was somewhat but not statistically significantly better after operation, contrary to our expectations.

Norman Swan: So when in fact the urologist decided to wait and see what happened to your cancer, those people had slightly poorer quality of life, compared to what you would have imagined being a poorer quality of life if they had erectile dysfunction or incontinence.

Gunnar Steineck: Scientifically we can say, at least they did not have decreased quality of life. Why so? First, erectile dysfunction also came in the watchful waiting group, and later on to higher prevalence. The growing tumour causes erectile dysfunction, the same for urinary leakage.

Norman Swan: So they ended up with it anyway.

Gunnar Steineck: Some did. And when it came the patients were very much more distressed by this, possibly because they didn't expect it. But we do see that they were more distressed by their erectile dysfunction and urinary leakage than when it occurred after an operation. Apart from that, they had urinary obstruction, but a prostatectomy is a very good treatment for urinary obstruction, so they had a better voiding after the operation.

Norman Swan: ... this constant anxiety, 'Am I going to develop a tumour, is it going to spread', that sort of thing.

Gunnar Steineck: Which, and again we don't have data, but to speculate on our findings that was coming from the fact that you got erectile dysfunction and urinary incontinence and of course the metastases which was more than twice as common after watchful waiting.

Norman Swan: Metastases being cancer spread. So watching and waiting had its own toxicity, if you like.

Gunnar Steineck's group in Stockholm has done a similar quality of life study following up women after treatment for cervical cancer.

Gunnar Steineck: Yes, we followed up cervical cancer survivors, which again in a nationwide study in Sweden, and we found that a compromised sexuality is as distressing in women as erectile dysfunction, a compromised sexuality is in men. Contrary to prior beliefs that sexuality is something only related to emotions and poetry in women, but the body is as important for women as for men, to have organ function.

Norman Swan: Just tell me about these women and the stage of cervical cancer and the treatments they were having.

Gunnar Steineck: They're talking about stage 1 II A and a radical hysterectomy.

Norman Swan: In other words, not enough that you just have a cone biopsy or a loop dissection, you actually have to take out their uterus.

Gunnar Steineck: Yes, it's a radical hysterectomy from cervical cancer, and we see that these women have a poorer lubrication during sexual arousal, a poorer vaginal elasticity and pain during intercourse. And we see that they are as much distressed by these factors as men are over erectile dysfunction.

Norman Swan: What are the implications for health care for women who have cervical cancer?

Gunnar Steineck: The implication is choose your surgeon, possibly preserving autonomic nerves is the way forward.

Norman Swan: These are the nerves that supply the glands for example and the operation of the vagina in the same way that urologists might preserve the nerves that supply the erectile tissue in the penis.

Gunnar Steineck: Yes. We believe that nerve damage is the reason for this compromised sexuality and if surgeons start to be very careful in identifying and saving these nerves, they'd indicate that women's' situation will improve.

Norman Swan: Gunnar Steineck is Professor of Clinical Cancer Epidemiology at the Karolinska Institutet in Stockholm.

Let's go back to the prostate because the media have been full of an angry debate about PSA testing. That's the prostate specific antigen test which some say is a useful screen for prostate cancer.

But recently the Chief Executive of the Cancer Council of Australia, Professor Alan Coates, came out and said the test was too unreliable and the treatment not convincing enough for him to have the test done on himself.

Urologists and prostate cancer groups were outraged.

But amidst all this flak, was does the evidence suggest?

Well researchers, led by Professor Jeanette Ward have developed a booklet to educate men on what to expect from the test and evaluate whether it made a difference to them.

Jeanette Ward is Professor of Public Health at the University of New South Wales.

Jeanette Ward: The booklet itself is quite comprehensive. We actually looked at the risks of developing or dying from prostate cancer. The actual status of what we know or don't know about the burden of proof, of whether screening action makes a difference to those risks. We also talked about the decision that would be made on the basis of what we know about whether the test is accurate or not, and the risks of treatment or the benefits one way or the other of not proceeding with any active treatment.

Norman Swan: And you aim to find out whether that actually helped men make the decisions?

Jeanette Ward: Exactly. We were more interested in whether men's knowledge became more accurate, whether they understood the risks more accurately, whether they had a more rational sense of the risk and worry about developing or dying from prostate cancer. We also measured their decision or conflict. So whether they actually were feeling more enabled to make an informed choice.

Norman Swan: Or had you made them more neurotic?

Jeanette Ward: Indeed. Exactly. Because there's been a view in the health education literature that especially for men who prefer doctors to make that decision, that giving them too much information in fact does stress them out. So we did want to measure that.

Norman Swan: And you kind of divided men into two groups, one who liked doctors to make their decisions for them, and one group who liked to be more active about the decision-making.

Jeanette Ward: We measured that attribute about men at baseline.

Norman Swan: And these were men over 40?

Jeanette Ward: Yes, 40 to 70 years of age.

Norman Swan: And what did you find?

Jeanette Ward: We actually were really pleased to see that even though the booklet itself was quite long, that as many men in both groups actually were as likely to read the booklet content. Indeed men who received our evidence-based booklet, were significantly more likely to recommend that to a man of their own age, 91%.

Norman Swan: Recommend the booklet?

Jeanette Ward: Exactly. But what was as important as that was that the outcomes themselves also were significantly better. We had better knowledge in the men who received our evidence-based booklet, reduced sense of worry about prostate cancer, a much more rational sense of what the risks of developing and dying from prostate cancer were compared with other diseases, but much more importantly, that their sense of enablement to make an informed choice was much better.

Norman Swan: And how did the choice go compared to not having received the booklet at all?

Jeanette Ward: Most interestingly, it was exactly the same.

Norman Swan: So it didn't change their minds?

Jeanette Ward: In terms of when we measured their intention to screen, they were the same in both groups.

Norman Swan: You in your leaflet, have got a decision tree, well not a decision tree, but what happens to a thousand men having a PSA test. Take us through a thousand men having a PSA test and what happens to them.

Jeanette Ward: Nine-hundred of those thousand men would actually have a normal test, although we do know that there is some fluctuation and variation by lab in terms of what might be classified as a normal test or not. And it also depends on a man's age. But in any case, we actually described in that flow chart what of those 900 men, the proportion that would actually have a cancer that was missed, and those that actually would be true negatives in that sense.

Norman Swan: So what proportion of the 900 with a negative test would have had cancer missed?

Jeanette Ward: Nine of those 900 would have had a missed cancer, but let's also remember though that we don't know quite what the impact of that false negative would be, in the sense that we still don't know whether those prostate cancers would have sat there indolent and not actually caused the man to come to any grief. And in terms of those 100 men that would have an abnormal PSA test result, in other words one that was out of the range of a normal blood value. There's a whole cascade then of further tests, ultrasound, biopsy, the fact that the biopsy itself has some risks, and then once you're on that cascade of events, it's very difficult to put the brakes on and say What is this that we're actually diagnosing here? Is this prostate cancer one that's likely to threaten my life?

Norman Swan: Nonetheless, of the 10% the 100 of the 1,000 who have a positive PSA test, how many really do have cancer, and how many don't?

Jeanette Ward: About a third have shown to actually have cancer on the result of the biopsy test.

Norman Swan: So two-thirds don't?

Jeanette Ward: Yes. But for those third of men found after their abnormal PSA test result to have prostate cancer -

Jeanette Ward: And this is 3% now of the total who've had the PSA test?

Jeanette Ward: The dilemma for them is what are their treatment choices, and we know from other overseas studies that there may be as much benefit to be had in what is known as watchful waiting, as in active interventional treatment, either surgery or radiotherapy, and we do also know from surveys of specialist groups that that is not by any means a consensus choice. Radiotherapists will recommend radiation therapy, urologists will recommend surgery for the same clinical stage in the disease.

Norman Swan: And the Swedish study showed that in fact the quality of life is no different. Watchful waiting has as much deterioration on your quality of life as the other two groups.

Jeanette Ward: So men have this ambiguous evidence base at the moment, in terms of us not knowing or knowing what to do about PSA screening for that very reason; we're right in the middle of that acquisition of good evidence that might help us make a decision.

Norman Swan: Professor Jeanette Ward of the University of New South Wales.

Wouldn't it be better though, to prevent prostate cancer in the first place? Well there's some evidence that populations which exercise and eat healthily seem to have a lower incidence of the disease.

And now a small study by James Barnard at the University of California, Los Angeles has had promising early findings to support this theory.

Maryke Steffens has the story.

Maryke Steffens: It's important to realise that these were not men with prostate cancer. It was an experiment to see what blood samples from them would do to prostate cancer cells in the lab. Professor Barnard put a small group of obese men on a diet of fruits, vegetables and whole grain foods, and an hour of exercise every day. The program was short, just 11 days, and the researchers took blood samples from these men before and after their diet and exercise regime. Blood was also tested from another group of men who had been adhering to a diet and exercise routine for a long time. Barnard calls them long-term compliers.

Extracts from all these blood samples were added to a dish of prostate cancer cells, to see what difference the regime made to how well the cancer cells grew.

James Barnard: The growth rate was reduced quite dramatically, about 30% over 11 days, and then when we compared the samples that we got from men who had been long-term compliers to the guidelines for the diet and exercise, to show that this just wasn't a transient change that occurred, why their growth rate was reduced by an additional 15%. So there was a dramatic decrease in the growth rate. But more importantly was the fact that we looked at what is known as apoptosis which is programmed cell death. In other words, these are cells that are already starting to disintegrate and which will eventually die. And in the baseline serum, about 3% of the cells were showing signs of apoptosis. It was about 40% of the cells in the 11-day subjects, and it was a little over 50% in the long-term compliers.

Maryke Steffens: Whatever is in the serum, is it slowing the growth of the prostate cancer cells, or actually killing them and reversing the growth of a tumour, just say.

James Barnard: It's doing both. What happens in our normal cells in the body is that we have a gene which is called P53, and the purpose of that gene is to survey the genome or all the DNA that's in our cells, and when that gene detects some aberration which could potentially become a cancerous cell, that gene then activates systems that try and repair the defect, they stop the cell from reproducing or they actually induce it to go into apoptosis. And so we think what's happening is when men go on the diet and exercise program, is they allow that gene to be activated to its fullest extent, and so the cells that we are observing in the cell culture are growing much more slowly and a lot of the cells are induced to actually go into apoptosis.

Maryke Steffens: So something was happening in the men's' bodies after 11 days of exercise and diet that was causing the prostate cancer cells to grow more slowly and commit cell suicide. James Barnard believes it might have something to do with insulin. If you're overweight and unfit, your body can become resistant to insulin, and your pancreas produces more to make up for it. A healthy diet and particularly muscle-building exercise, helps your body regain its insulin sensitivity. Now most of us think about insulin in relation to its effect on blood sugar, but there's also a network of chemical messengers associated with insulin.

According to Professor Barnard, some of them affect a gene called P53. P53 is thought to control cell growth and some cancer processes. The theory is that with the high insulin levels you might get from an unhealthy lifestyle, this message system goes haywire. So if you eat right and exercise, the balance may return, giving your body a better chance of repairing potentially cancerous cells. But what exactly does fit and healthy mean? According to James Barnard it's eating a low-fat, high fibre diet with reduced meat and dairy products, combined with one hour of exercise 4-6 days a week. It sounds tough, but at least in this small study, the effects seemed to be apparent in just a short time.

James Barnard: Many, many changes that would improve the health of the individual can occur within a two-week period of time or an 11-day period of time.

Maryke Steffens: It's actually really amazing because when someone says, 'Oh, I need to go on a diet, and I need to do exercise', they're put off by the fact that it might take them three months to see that they're losing weight, or to feel better about their diet. So you're saying that it actually takes only about two weeks.

James Barnard: People have associated obesity with all kinds of health problems, and the truth of the fact is that it's probably not the obesity that's causing the health problems that we have, it's a manifestation of lifestyle, the diet and the lack of regular exercise. Now fortunately, most of the health problems can be corrected in a very short period of time. But obviously you can't correct obesity in a short period of time because the men were obese when they came, 11 days later when they went home, they were still obese, but their overall health status was dramatically improved. Their cholesterol levels were down, their insulin level was down and the changes that we saw in the tumour growth rate would indicate a dramatic reduction in the risk for prostate cancer.

Maryke Steffens: Is there a minimum or a maximum that you need to exercise in order to get these benefits?

James Barnard: If you look at what the American College of Sports Medicine recommends, they recommend at least a half-hour a day. I think an hour a day is more appropriate. The human body I think was designed to be physically active, just like it was designed to eat a diet primarily of grains, fruit and vegetables.

Maryke Steffens: As unappetising as brown bread and a brisk walk are for some, it's good news for implementing preventative measures. But what about men who already have prostate cancer? Well, Barnard says that early results from another experiment are positive.

James Barnard: That study is ongoing at the present time, and we had some preliminary data at the end of one year that the men who went on the low-fat diet and exercise program, none of them have gone on to invasive treatment, where I think seven of the men who are on standard medical care have gone on to invasive treatment.

Norman Swan: James Barnard of UCLA. The Health Report's Maryke Steffens investigated.


Steineck G. et al. Quality of Life after Radical Prostatectomy or Watchful Waiting. New England Journal of Medicine, Vol. 347:790-796, September 12, 2002, No. 11

Holmberg L. et al. A Randomized Trial Comparing Radical Prostatectomy with Watchful Waiting in Early Prostate Cancer. New England Journal of Medicine, Vol. 347:781-789, September 12, 2002, No. 11

Patrick C. Walsh. Surgery and the Reduction of Mortality from Prostate Cancer. (Editorial).New England Journal of Medicine, Vol. 347:839-840, September 12, 2002, No. 11

Gattellari M, Ward J. Does evidence-based information about prostate cancer screening enhance consumer decision-making? A randomised controlled trial. Journal of Medical Screening (In Press)


Dr Gunnar Steineck
Professor of Clinical Cancer Epidemiology,
Department of Oncology and Pathology,
Clinical Cancer Epidemiology,
Karolinska Institutet,
SE 171 76 Stockholm,
Professor Jeanette Ward
Division of Population Health
South Western Sydney Area Health Service
Locked Bag 7008
Liverpool NSW 1871
Professor James Barnard
Department of Physiological Science
University of California, Los Angeles,
405 Hilgard Avenue
Box 951361
Los Angeles, CA 90095-1361

Further Information

James Barnard's website


Dr Norman Swan
Brigitte Seega