Systematic review and meta-analysis of randomized controlled trials

Existing evidence from randomised controlled trials does not support routine population screening for prostate cancer, concludes a study published on bmj.com today.

However, a second study also published today suggests that a single test at age 60 could identify men who are most likely to develop and die from prostate cancer. These men could then be monitored more closely, while others could be exempt from further screening.

Prostate cancer is one of the most common cancers among men worldwide. Screening is widely used in many countries, but it remains controversial because experts can't agree whether the benefits of screening outweigh the potential harms and costs of over-diagnosis and over-treatment of healthy men.

In 2006, a review of two randomised controlled trials concluded that there was not enough evidence to support routine prostate cancer screening. Since then, four new trials have been published.

So Professor Philipp Dahm and colleagues at the University of Florida reviewed all six trials, involving 387,286 participants. They found that screening aids in the diagnosis of prostate cancer at an earlier stage, but does not have a significant impact on mortality, and comes at the risk of over-treatment.

The authors say there is insufficient evidence to support actively inviting all men in certain age groups to attend screening for prostate cancer (as happens with breast cancer screening for women), and they suggest men should be better informed about the uncertainties associated with screening.

In the second study, Professor Hans Lilja and colleagues show that a single prostate-specific antigen (PSA) level test at age 60 strongly predicts a man's lifetime risk of diagnosis and death from prostate cancer.

They found that 90% of prostate cancer deaths occurred in men with highest PSA levels at age 60, whereas men with average or low PSA levels had negligible rates of prostate cancer or death by age 85. Their results suggest that at least half of men aged 60 and older might be exempted from further prostate cancer screening, which would reduce over-diagnosis and over-treatment.

In an accompanying editorial, Gerald Andriole, Chief of Urologic Surgery at Washington University School of Medicine, suggests that PSA testing should be tailored to individual risk.

He recommends that young men at high risk of prostate cancer, such as those with a strong family history and higher baseline PSA concentrations, should be followed closely, while elderly men and those with a low risk of disease could be tested less often, if at all. "Approaches such as these will hopefully make the next 20 years of PSA based screening better than the first 20," he says.

Source: BMJ