Latest PSA data supports screening
MedWire News: Screening men for prostate-specific antigen (PSA) significantly reduces their long-term risk for death from prostate cancer, shows an updated analysis of the European Randomized Study of Screening for Prostate Cancer (ERSPC).
After a median follow up of 11 years, there was a significant 21% relative reduction in the risk for death from prostate cancer in the screening group compared with a control group that received no screening. This reduction increased to 29% after adjustment for noncompliance.
The study's lead author Fritz Schröder (Erasmus University Medical Center, Rotterdam, the Netherlands) and colleagues say that screening for prostate cancer is controversial. Initial results from the ERSPC showed a significant 20% relative reduction in the rate of death from prostate cancer at 9 years among men offered screening for PSA.
In spite of this, a literature-based analysis of benefits and harms of PSA screening, conducted by the US Preventive Services Task Force, recommended against the use of PSA testing in asymptomatic men.
In the present study, Schröder and team updated prostate cancer mortality data in the ERSPC with an additional 2 years of follow-up.
The study involved 182,160 men between the ages of 50 and 74 years at entry, with a predefined core age group of 162,388 men of 55 to 69 years of age. The trial was conducted in eight European countries.
The men were randomly assigned to receive either PSA screening every 4 years or to a control group that received no such screening.
During the 11-year follow-up period, a total of 6963 prostate cancers and 299 deaths from prostate cancer were reported in the screening group compared with 5396 and 462, respectively, in the control group.
The absolute reduction in mortality in the core screening group was 0.10 deaths per 1000 person-years or 1.07 deaths per 1000 men who underwent randomization. This compares with a reduction of 0.71 deaths per 1000 men who underwent randomization observed in the initial analysis with the shorter follow-up period.
The researchers calculated that 1055 men would need to be invited for screening and 37 cancers would need to be detected to prevent one death from prostate cancer at 11 years of follow up.
Of note, during years 10 and 11 of follow-up, there was a 38% relative reduction in the risk for prostate cancer mortality among men in the core age group, indicating that the benefits of screening increase with time. By contrast, there was no indication of a mortality reduction among men aged 70 years or older who underwent screening. Therefore "this upper age limit and life expectancy warrant careful consideration in future screening programs," Schröder et al remark in The New England Journal of Medicine.
There was also no significant benefit of PSA screening on all-cause mortality.
The researchers say that the current analysis consolidates their previous finding that PSA-based screening significantly reduces mortality from prostate cancer.
However, they conclude: "More information on the balance of benefits and adverse effects, as well as the cost-effectiveness, of prostate-cancer screening is needed before general recommendations can be made."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Laura Cowen