EAU 2017: Con – Prostate Cancer Screening: Time to change recommendations for PSA testing

London, England (UroToday.com) In this session, Dr. Grubb defended PSA testing. He began by suggesting that he and Professor Hugosson likely have a similar viewpoint on these issues. Updated findings from the prostate arm of the United States Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) trial continues to demonstrate no difference in PCSM after 15 years’ follow-up. In reality, this was not a trial of PSA screening versus no screening at all. Rather, up to 85% of patients in the control arm had a PSA test. Thus, it is more correctly understood as a structured screening versus an opportunistic screening trial in which no difference was demonstrated.

In contrast, the EORTC trial demonstrated a 20% reduction in prostate cancer-specific mortality with a number needed to screen of 781. This trial has been criticized for variable screening protocols, treatment differences by location, and differential use of androgen deprivation therapy in the control group. A suggestion was made that these data could be considered separately and in the context of a meta-analysis. Nonetheless, PSA screening did demonstrate improved prostate cancer-specific survival.

Current screening recommendations vary from the most extreme recommending no PSA screening at all (United States Preventive Services Task Force, USPSTF) to more moderate screening protocols specifying ideal age groups for screening and shared-decision making models. Unfortunately, PSA screening has seen a marked reduction in the United States after the 2012 USPSTF recommendations against its use. This has led to a reduction in diagnosis of both indolent and clinically significant prostate cancers. The concern remains the mathematical certainty that an increase in incurable advanced prostate cancer will result from this approach.

More moderate screening recommendations agree that a baseline PSA may be beneficial. In fact, several studies demonstrate that men with a low initial PSA are unlikely to harbor lethal prostate cancer (Preston et al. JCO 2015). Moreover, the majority of the guidelines support less frequent than annual screening. The NCCN has specific recommendations in which screening intervals are risk-stratified and intervals of 2-4 years are recommended. Finally, PSA screening should be discontinued when life expectancy is less than 10 years. While there is evidence of reduced screening in this population, men with less than 10 years of life expectancy still receive a substantial number of PSA tests representing an area to target for improvement.

Lastly, Dr. Grubb touched on adjunct testing. Prostate Health Index (PHI) has been shown to avoid 24-36% of benign biopsies and 17-24% of biopsies in men with low grade prostate cancers. The risk of this is only a 4% chance of missing significant or aggressive prostate cancers. Similarly, the 4K score has been demonstrated to avoid 37% of unnecessary biopsies. Thus, the NCCN guidelines now recommend “augmented” PSA-screening as an option using free PSA, PHI, or 4K score.

In conclusion, Dr. Grubb believes that PSA remains the best screening test available for early detection of prostate cancer. Nuances in screening are important and are highlighted in the AUA, EAU, and NCCN guidelines. Moreover, he believes that the future of prostate cancer screening is PSA + other testing (MRI, 4K, PHI, etc.).

Speaker(s): R. Grubb, St. Louis, MO, USA

Written By: Benjamin T. Ristau, MD, SUO Fellow, Fox Chase Cancer Center, Philadelphia, PA

at the #EAU17 - March 24-28, 2017- London, England