PSA Screening Reduces Prostate Cancer Mortality

A new report with extended follow-up from the European Randomized Study of Screening for Prostate Cancer (ERSPC) strengthened the study’s previous findings by finding once again that prostate-specific antigen (PSA) screening for men significantly reduced mortality from prostate cancer, but did not have an affect on all-cause mortality. These latest findings, which include a median of 11 years of follow-up data, were reported in the New England Journal of Medicine [2012;366(11):981-90].

The ERSPC is a multi-center trial involving 182,160 men that began in 1991 to evaluate whether PSA screening had an affect on prostate-cancer mortality. Researchers previously reported the study’s initial findings; however, in this update, there are 2 additional years of follow-up data incorporated into the results.

In the trial, researchers included 182,160 men between 50 and 74 years of age, with a predefined core group of 162,388 men 55 to 69 years of age. Study participants were randomly assigned in participating centers across 8 European countries to either a screening group where participants were offered PSA-based screening or a control group where they were not.

Most centers used a PSA of 3.0 ng per milliliter or higher as an indicator that a biopsy may be needed once the screening had been conducted.

They evaluated mortality in participants in both trial groups who had been diagnosed with prostate cancer and also gathered overall mortality data from national registries to conduct their analysis.

Researchers identified the primary outcome of the study as prostate-cancer mortality.

In this latest follow-up, they found that the screening group had a relative reduction in the risk of death from prostate cancer of 21% (rate ratio, 0.79; 95% confidence interval [CI], 0.68-0.91; P=.001) and that relative reduction in the risk of death increased to 29% after researchers adjusted for noncompliance and selection bias.

In addition, they reported that the screening group had an absolute reduction in mortality of 0.10 deaths per 1000 person-years or 1.07 deaths per 1000 men who underwent randomization.

Overall, there were 299 deaths from prostate cancer in the screening group compared with 462 in the control group.

When researchers added data from the 2 additional years of follow-up, they found that the rate ratio decreased from 0.85 (95% CI, 0.71-1.03) for years 1 to 9 of the study to 0.79 (95% CI, 0.67-0.92) for years 1 to 11.

Further evaluation of the additional follow-up found that for years 10 and 11 there was a rate ratio of 0.62 (95% CI, 0.45-0.85) and a corresponding relative risk reduction of 38%.

Researchers noted that for 1 death from prostate cancer to be prevented at 11 years of follow-up, 1055 men would need to be offered screening and 37 cancers would need to be discovered.

The study’s authors found PSA screening had no effect on all-cause mortality.

Researchers acknowledged that there may have been some biases that affected their study and identified these possible biases as an inability to ensure that the differences found between the control and screening groups were not due to differences in case management, possible errors in the assignment of causes of death, and a portion of the men in the control group (an estimated 20%) who received PSA screening during the early follow-up period.

They concluded that more information about cost-effectiveness, benefits, and adverse effects of PSA screening is necessary to determine any PSA screening recommendations.