PSA Screening for Prostate Cancer More Beneficial Than Previously Recognized

PSA screening is associated with a greater prostate cancer (PCa) survival benefit than widely recognized, according to an extrapolation of findings from the 16-follow-up of the European Randomized Study of Screening for Prostate Cancer (ERSPC).


This new analysis involved modeling to project the effect of PSA screening over a 25-year time period and arrived at estimates showing that, compared with ERSPC estimates, far fewer men needed to be screened and diagnosed with PCa to prevent 1 PCa death, Jonathan E. Shoag, MD, of Weill Cornell Medicine in New York, and colleagues reported in the New England Journal of Medicine.


“As clinicians who screen, diagnose, and treat patients with prostate cancer and as statisticians who are devoted to understanding the effects of cancer screening, we suggest that the balance of benefits and harms of screening may be more favorable than is generally appreciated,” the authors concluded.


According to the ERSPC update, which was published in European Urology in 2019, an estimated 570 men aged 55 to 69 years would have to be screened and 18 new PCa cases would need to be diagnosed to prevent 1 PCa death over 16 years from study randomization. “This benefit is qualitatively similar to recommendations supporting breast cancer screening, with the need to screen 1250 women from 50 to 59 years of age, and 769 women from 70 to 74 years of age to prevent one death from breast cancer at 10 years.”




Dr Shoag’s team stated, however, that 16 years of follow-up from study randomization may not provide a “sufficient time horizon” to examine the mortality benefit from screening because men often begin screening in their 50s and the median age at death from PCa is 80 years. Based on their analysis, they estimated that 385 men would have to be screened and 11 additional cases of PCa would need to be diagnosed to prevent 1 PCa death over a 25-year time span.


In an interview, Dr Shoag called these projections extremely conservative and pointed out that PSA screening has benefits beyond lowering PCa death risk, such as prevention of metastatic disease and the impaired quality of life associated with its treatment.


Regarding the PSA test, he observed, “It’s been in use for 3 decades, and we’re turning our backs on it based on misguided assumptions.”


Data suggest that the incidence of metastatic PCa at diagnosis is rising after many years in decline, and this apparent trend is part of the reason for conducting the new analysis, said co-investigator Jim C. Hu, MD, MPH, also of Weill Cornell Medicine. A plausible explanation for this trend is a decline in screening following release of 2012 guidelines from the US Preventive Services Task Force (UPSTF) that discouraged screening.


Dr Hu said information on PSA screening disseminated by the task force is misleading and based on obselete data. In particular, he has issues with a chart aimed at patients titled “Is Prostate Cancer Screening Right for You,” in which the task force recommends that for men aged 55 to 69 years, the decision is receive PSA screening should be an individual one. The chart informs patients about the sequence of events set in motion by PSA screening, starting with 1000 men offered screening. According to the chart, 240 will get a positive result showing an elevated PSA level, and of these, 100 will be found to have PCa on a prostate biopsy. The chart also informs patients about the potential side effects of prostate biopsies (pain, bleeding, and infection) and complications of treatment, namely erectile dysfunction and urinary incontinence. Dr Hu said the information provided in the chart is outdated, fails to capture recent trends in PCa detection and management, and does not represent the current standard of care. One trend is the use of prebiopsy magnetic resonance imaging scans of patients with an elevated PSA to identify suspicious lesions. If none are found, patients need not undergo biopsy. Dr Hu noted that approximately one third of men with an elevated PSA do not have to undergo biopsy. Another trend is the use of active surveillance to manage most men with low-risk PCa, thus addressing a concern about overtreatment.


References


Shoag JE, Nyame YA, Gulati R, et al. Reconsidering the trade-offs of prostate cancer screening. N Engl J Med. 2020;382:2465-2468. doi: 10.1056/NEJMsb2000250



Hugosson J, Roobol MJ, Mansson M, et al. A 16-year follow-up of the European Randomized Study of Screening for Prostate Cancer. Eur Urol. 2019;76:443-51. doi: 10.1016/j.eururo.2019.02.009

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