PROSTATE cancer is the most commonly diagnosed cancer and the second leading cause of cancer-related death among men. Approximately 50% of patients with locally treated prostate cancer eventually develop incurable metastatic disease. It has been found, as with most cancers, that the earlier you detect the disease, the better the outcome. Yet Ireland still has no prostate cancer screening programme in place. Rory Hafford travelled to Birmingham, England for the XVIIth Congress of the European Association of Urology where he spoke with Mr John Anderson of the Royal Hallamshire Hospital in Sheffield about the latest research into screening for prostate cancer. Here are Mr Anderson’s findings…

PROSTATE-specific antigen (PSA) is a valuable marker for prostate cancer and is widely used in the detection of the disease; 33-52% of men with a PSA level of >4 ng/mL will have invasive cancer on biopsy.(1) Population PSA screening has been introduced in some countries, for example the USA, and has led to marked changes in the incidence, characteristics and patterns of care of the disease.(2)

Population-based studies have established that a significant proportion of men with prostate cancer who do not receive early treatment are at risk of death from the disease. For example, in a study of 2,570 men registered with the Danish Cancer Registry between 1943- 1986 who had a life expectancy of >10 years and were managed by observation (watchful waiting), 61.8% eventually died of prostate cancer.(3) although longterm disease-specific mortality in other series has been much lower (for example, the study of Johansson, et al(4)), these included a high proportion of older men with well differentiated tumours.

Age-adjusted survival rates in these men do not differ significantly from those of the general population, whereas patients with moderately or poorly differentiated tumours have been shown to experience progressively increasing loss of life expectancy when managed by watchful waiting (Fig. 1).(5)

The early stages of prostate cancer are generally asymptomatic and in the pre- PSA era, the disease was generally only diagnosed at advanced and incurable stages. The rationale for PSAscreening is that earlier diagnosis enables patients to receive potentially curative treatment, thereby reducing the mortality associated with the disease. in the USA, the mortality rate from prostate cancer has declined since screening was introduced (-2.1%/year since 1991), although screening alone is unlikely to be the only cause of this decline.(2)

Differences in mortality rates in the Austrian state of Tyrol and the rest of Austria have also been reported since the introduction of population screening in the Tyrol.(6) The latter findings are controversial and may at least be partly due to a change in treatment practices (increased rates of radical surgery) predating the introduction of screening.

BENEFITS

The true benefits of PSA screening and early treatment can only be established by prospective randomised studies with mortality as an endpoint. Three such studies are ongoing. The Laval University Prostate Cancer Screening Program (LUPCSP) study was started in 1988 and involves 46,193 men aged 45-80 years who were randomised to a screening or control group in a ratio of 2:1 (Figure 2)(7)

The prevalence of prostate cancer at the first screening visit was 3.0% and the mean annual incidence over the 8-year follow-up period was 0.52%. Nearly 75% of cancers diagnosed following screening were clinically localised (stages A2-B2) and, overall, 78% of patients received therapy of curative intent with or without hormonal therapy. These outcomes did not differ with respect to initial screening allocation and the results for the sub-populations of screened and un-screened patients were, therefore, pooled (less than 25% of the invited men were actually screened, while 7% of the control group underwent screening). Taking this into account at follow-up, the prostate cancer death rates in men who did and did not undergo regular screening were 15.0 and 48.7 per 100,000 man-years, respectively (odds ratio 3.25 in favour of screening; p<0.01)(7)

Results from the other two studies, the European Randomised Study of Screening for Prostate Cancer (ERSPC) and the Prostate, Lung, Colon and Ovarian (PLCO) trial, which began in 1994 and ’95 respectively, will not be available for several years.

In conclusion, younger men are those with moderately or poorly differentiated tumours have a substantial risk of prostate cancer-related death if treatment is not initiated early in the course of their disease. Although randomised studies evaluating PSA screening are still ongoing, current evidence suggests prostate cancer mortality will be reduced by PSA screening and early treatment, although the magnitude of the benefit needs to be confirmed by the ongoing randomised studies of PSA screening.

THE Association of General Practitioners is an association founded in the turmoil of the reality of lives of men and women working in General Practice in the 1980s. Services were being cut wholesale as Ireland once more descended into an economic nightmare.

All of the Association's original members were in the IMO, but the retention tax was the last straw and the easy facility which the then IMO executive offered the Government was too much for some. As GPs then had to pay taxation in advance of earnings, a hardship verging on bankruptcy descended on many practices and it took ten years and a High Court decision to reverse the injustice of the original mistake.

We are now facing into a very serious situation, with two of our members about to be brought before the courts on charges which have nothing to do with the real issues. Are we living in a kind of neostalinist Ireland? Are we being persecuted for being good doctors? Are we to be legally indicted for doing the best for our patients? The lie is that it is all about 'importation of medicines without a wholesale licence'. It is not! It is about the right of a doctor to treat his/her patients as they think best, with the benefit of all the knowledge and experience behind him/her. Certain interests in this country want to control our professional rights and freedoms. They will deny this of course - but, unfortunately it's true.

The AGP will never step back from this type of issue. Others, maybe the majority, will stand idly by and let it happen. However, the price of freedom is eternal vigilance, an old cliche, but nevertheless sound. Let those who support us, either openly or secretly, step forward now. There is a real battle about to commence and to the victor will go the soul of the greatest profession of all...medicine! As doctors working at the coalface of humanity, we must ensure that we win on this. Join the AGP and do your bit.

- Dr Pat Crowley