News
EMUC Debate: pro and contra arguments on mass PCa screening
Friday, 11 December 2009- Pro and contra arguments on the benefits of prostate cancer screening were presented during the recent 2nd European Multidisciplinary Meeting on Urological Cancers (EMUC) with both camps debating a number of issues such as survival rates, QoL, risk of over treatment and over diagnosis and a closer scrutiny of the implications from two major trials (ERSPC and PLCO), amongst other topics.
Professors Teuvo Tammela (Tampere, Finland) and Freddie Hamdy (Oxford, UK) took pro and contra positions, respectively. Underscoring the impact of prostate cancer (PCa) incidence in Europe, Tammela said there are 350,00 new cases diagnosed each year in Europe, with PCa accounting for 20% of all male cancers. And in some countries like Finland and Sweden, PCa accounts for one-third of the cases and is the most common male cancer. He added there were 87,000 cancer deaths each year in Europe.
He then cited the ERSPC (European Randomised Study of Screening for Prostate Cancer) which randomised 182,160 subjects to the screening and control groups and which showed a clear reduction in death mortality.
"There is a need to screen because it has been shown scientifically that screening decreases prostate cancer mortality by 20% to 31%. And most probably that with longer follow-up, the mortality and morbidity benefits will increase," Tammela said.
Moreover, Tammela noted that the reduction in death is similar to the 30% reduction in mortality in women who undergo mammography and the 37% reduction in the prostate cancer mortality that occurred in the US following the introduction of PSA screening in the 1980s.
"One can ask what is the difference between mammography and PSA screening? Is it so that a male cancer is not considered as important as female cancer? Or why is it that men’s cancer is not taken seriously?" Tammela pointed out.
Furthermore, Tammela said that the aside from reduced mortality rates, the ERSPC study also indicated that with early detection, bone metastases decreases by 41%. “ Bone metastases kill the PCa patient and it causes pain, increases morbidity and decreases QoL. It also means an extra load or costs for the health care system,” he added.
Regarding over diagnosis, Tammela said: "We know that the problem caused by inevitable over diagnosis can be solved by using active surveillance…We avoid aggressive treatment in men with indolent cancer."
He argued that the reality of 'wild' screening which is common in many European countries should be replaced by organised screening programmes which would be more structured, focused and cost effective. "The load on the health care system would increase only mildly and costs would not increase significantly," Tammela said in response to criticisms regarding the cost-effectiveness of a mass screening programme,
In his concluding arguments, Tammela insisted that a mass PCa screening programme in Europe should be started because screening decreases PCa mortality and incurable disease, and that there is no negative impact on QoL. He also reiterated that active surveillance overcomes the problem of over diagnosis and that a screening programme is more structured, focused and cost-effective than so-called ‘wild’ screening which is taking place.
Counter arguments
In his counter arguments, Prof. Hamdy hammered on the dilemmas inherent in a mass screening programme and the doubtful impact on or benefits not only in terms of added costs to the healthcare system, but more importantly to the patient’s health and quality of life.
"What are the dilemmas? The dilemmas are largely that there is significant risk of over detection and a significant risk of over-treatment and the figures speaks for themselves," said Hamdy. Citing the same ERSPC data which shows a prostate cancer reduction mortality by 20% , Hamdy said that in real terms to prevent one PCa death, 1,400 men need to be screened in the age group 55-69 years, with 48 need to be treated.
In comparison with the breast cancer screening, Hamdy said that to prevent one breast cancer death, 1,000 women need to be screened, and 6 need to be treated
He added: "I think it is dangerous to fiddle with the statistics and to go to the 31% by starting to include only patients who have been screened and there is a danger of falling into the same trap that Fernand Labrie fell into in the 1980s with statistical calculations."
Pressing on with his arguments, Hamdy said: “Do physicians want screening? Yes they do, but we tend to forget this statement: first do not harm (primum non nocere). Do men want screening? Yes they tend to but they forget that screening is also about changing identities. You are a healthy man and suddenly you are given a new passport that you do not want. It’s a cancer passport.”
"Screening is about becoming a patient. It’s about making difficult choices of treatment. Whether you have active surveillance or surgery, robotic, MIRT, radiotherapy or brachytherapy. You’re making difficult choices… and its about suffering from complications of unnecessary treatment," he added.
Pros and cons
He then summarised the pros of screening such as a possible improved survival with recent high level evidence (ERSPC), a possible improved QoL (but with no evidence to date); a profound stage migration (high level evidence) and emerging evidence regarding the ability to determine risk by PSA baseline, maybe kinetics/isoforms; and the ability to identify low risk disease (emerging evidence).
But Hamdy said the contra arguments are more clearly persuasive such as the very strong evidence of over-detection (number needed to be screened n= ~1,400) and over-treatment. Moreover, there is also good evidence of morbidity and complications from treatment and an equally good evidence of added cost to health providers.
"There is very limited evidence on the ability to maintain patients with low risk disease on active monitoring/surveillance. The majority of patients (30% to 40%) in active surveillance programmes will go on to active treatment because of anxiety not necessarily because of disease progression," Hamdy argued. He added that reduction in prostate cancer mortality, although prevalent in some countries, is apparently unrelated to screening/treatment of clinically localised disease.
Summing up his arguments, Handy said that amongst the challenges is that there is a need to interpret the results from the ERSPC carefully.
"We also need to await the treatment effectiveness results from ongoing studies such as PIVOT and ProtecT. We need to reduce over-detection not increase it by introducing screening. We need to minimise over-treatment not by diagnosing more patients and putting them in active surveillance because they will not stay in active surveillance, and we need to educate physicians and public," said Hamdy.
He also gave several recommendations such the need to develop algorithms to identify low risk disease, and to discover reliable novel biomarkers- diagnostic, predictive and prognostic. He also noted that need to discover genetic predisposition and men ‘at risk’ through high-throughput platform analyses using well characterised cohorts of patients and controls.
EAU Secretary General Prof. Per Anders Abrahamsson, who acted as moderator, then resumed the voting from the audience with the question “Are we ready to implement PCa mass screening in Europe?” Interestingly, before the debate there was a 50-50 split amongst the audience, but which shifted to the contra camp by a wide margin after the presentations.
