A new quality of life analysis adds fuel for both sides in the ongoing debate over benefit versus harm of routine PSA screening for prostate cancer in asymptomatic men, according to a report in the New England Journal of Medicine.
Researchers applied complex modeling to the European Randomized Study of Screening for Prostate Cancer (ERSPC), which reported screening cuts prostate cancer mortality by 29%. They agreed that screening saves lives but found that the benefit was undercut by long-term effects of overdiagnosis and overtreatment.
The new analysis calculates the ERSPC results in quality-adjusted life-years (QALYs), a measure the investigators based on health states ranging from "death or worst imaginable health" to full health and on treatment-related complications such as urinary incontinence, bowel dysfunction, and sexual dysfunction.
"Our model predicts that there would be nine fewer prostate cancer deaths and 73 life-years gained over the lifetime of 1,000 men who underwent annual screening between the ages of 55 and 69 years," write Dr. Eveline A.M. Heijnsdijk of Erasmus Medical Center, Rotterdam, the Netherlands, and her coauthors.
"The harms caused by the introduction of such screening would be the overdiagnosis and overtreatment of 45 cases and the loss of 1,134 life-years free of prostate cancer (i.e., lead-time years). After adjustment of the number of life-years gained from screening by consideration of quality-of-life effects, 56 QALYs would be gained, which is a 23% reduction from the predicted number of life-years gained."
Extending screening to men aged 74 years would increase the number of unadjusted life-years gained to 82, but QALYs would stay the same at 56, according to the authors (N. Engl. J. Med. 2012;367:595-605 [doi: 10.1056/NEJMoa1201637]).
"The predicted adjustment for quality of life is due to the long-term side effects from treatment. Men in whom cancer has been overdiagnosed and those in whom cancer has not been overdiagnosed will live many years with the adverse effects of treatment," they write.
The U.S. Preventive Services Task Force (USPSTF) set off a furor in May when it took a stand against PSA screening for prostate cancer in healthy men, arguing that the harms outweigh the benefits. Debate has centered on interpretation of data from the ERSPC trial (N. Engl. J. Med. 2012;366:981-90) and the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial (N. Engl. J. Med. 2009;360:1310-9), with proponents of universal screening arguing that it saves lives.
Dr. Heijnsdijk and her coauthors did not take a stand on screening, proposing instead that more long-term data are needed along with more research and more modeling to calculate cost-effectiveness.
"It is essential to await longer follow-up data from the ERSPC, as well as longer-term data on how treatment and active surveillance affect long-term quality of life, before more general recommendations can be made regarding mass PSA screening," they conclude.
The analysis was supported by grants from the Netherlands Organization for Health Research and Development, Europe Against Cancer, the European Union; agencies or health authorities in participating countries; and by unconditional grants from Beckman Coulter.
Dr. Heijnsdijk disclosed receiving consulting fees from Beckman Coulter and her coauthors reported relationships with various companies. Dr. Sox is a former chair of the U.S. Preventive Services Task Force and serves on the board of the Informed Medical Decisions Foundation, which makes decision aids for prostate cancer screening.