PSA Screening and Effects on Quality of Life

Benefits of screening for prostate cancer include reduction in disease-related mortality, increase in the number of life-years gained, and a reduction in the rate of advanced disease. However, prostate-specific antigen (PSA) screening is associated with substantial adverse effects.

At 9 years of follow-up, the European Randomized Study of Screening for Prostate Cancer (ERSPC) showed a significant relative reduction of 20% in prostate-cancer mortality among men who had PSA screening. Eleven year follow-up results of the ERSPC found the relative reduction in prostate-cancer mortality in the screening group was 29% following adjustment for selection bias.

In the US Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, there was no mortality reduction in the screening group; however, the rate of contamination with respect to nonstudy screening in the control group was high, and the rate of biopsy compliance was low, according to researchers.

In the ERSPC screening group, the cumulative incidence of prostate cancer was 7.4%, compared with 5.1% in the control group. According to researchers, 10% to 56% of the tumors detected with screening would “never had led to clinical symptoms.” However, those screen-detected cancers are often treated, creating risks of adverse effects.

The researchers recently utilized a model based on data from the ERSPC to quantify the effects of screening strategies on prostate-cancer mortality and on quality of life. They also analyzed the harms and benefits for a range of treatment, mortality-reduction, and screening scenarios. They reported results in the New England Journal of Medicine [2012;367(7):595-605].

There have been 2 specific studies on quality of life following treatments for prostate cancer. Prior to surgery, 1% to 2% of the patients were incontinent and 31% to 40% were impotent. At 18 to 52 months after surgery, 6% to 16% of men who underwent radical prostatectomy were incontinent as were 3% of those who underwent radiation therapy. At 6 to 52 months after surgery, 83% to 88% of men who were potent prior to treatment who underwent radical prostatectomy were impotent, as were 42% to 66% of those who underwent radiation therapy.

The researchers modeled the effect of various health states in both the presence and absence of annual screening over the lifetime of 1000 men between 55 and 69 years of age. They also calculated the number of life-years and quality-adjusted life-years (QALYs) gained or lost as a result of the differences between the numbers of men within each health state.

Per 1000 men of all ages who were followed for their entire life span, the models predicted that annual screening of men between 55 and 69 years of age would result in 9 fewer deaths from prostate cancer, a 28% reduction; 14 fewer men receiving palliative therapy, a 35% reduction; and a total of 73 life-years gained (average, 8.4 years per prostate-cancer death avoided).

The models predicted that in order to prevent 1 death from prostate cancer, 98 men would need to be screened and 5 cancers would need to be detected. Screening of all men between 55 and 74 years of age would result in more life-years gained (82) but the same number of QALYs (56).

In conclusion, the researchers said, “The benefit of PSA screening was diminished by loss of QALYs owing to postdiagnosis long-term effects. Longer follow-up data from both the ERSPC and quality-of-life analyses are essential before universal recommendations regarding screening can be made.”