San Diego, CA USA (UroToday.com) Dr. Stacy Loeb, MD presented on the controversy of prostate cancer screening. Mathematical models suggest about 45-70% reduction in prostate cancer mortality due to PSA-era screening. However, we have conflicting results from randomized-controlled trials. PLCO trial suggested no difference in prostate cancer mortality between organized screenings versus usual care. However, the data from this trial is limited due to a high level of controls who have had at least 1 PSA screening before or during the trial. ERSPC trials suggest 21% reduction in prostate cancer mortality at 13 years.
The conflicting results from trials lead to most extreme recommendations by 2012 USPSTF, which recommended against any PSA screening for men of all ages. This was subsequently echoed in 2014 by Canadian Task Force. However, neither of these task-force included prostate cancer specialists.
Modeling studies suggest that the consequences of these task force recommendations may eliminate overdiagnosis at the expense of 2-fold increase rate of metastatic cases and 13-20% increase in prostate cancer deaths by 2025.
Surveys on patient reactions to USPSTF guidelines suggest that only 13% planned to follow the USPSTF recommendations. Additionally, several medico-legal cases of prostate cancer identify failure to perform an initial PSA test and failure to follow-up of an elevated PSA as the two leading reasons for a lawsuit.
Shared Decision-Making may be the paradigm. AUA, EAU and NCCN recommend this approach. Shared decision-making involves discussion of the risks of benefits of PSA screening as well as discussion of patient preferences. Studies suggest that this is under-utilized with only about 8% of patients polled in National Health Interview Survey reporting that a shared-decision making took place. What is concerning is that 88% of unscreened men reported no discussion on PSA screening.
Optimal screening paradigm involves discussion of baseline PSA, individualized screening intervals, utilization of markers of greater specificity, and using a multivariable, risk-adapted approach.
Baseline PSA in young men is important. PSA>0.7 in men in their 40’s is a strong predictor of prostate cancer risk than family history, race or DRE (Loeb et al, Urology 2006).
Screening frequency is variable different in AUA, EAU and NCCN recommendations and needs to be personalized to a patient.
PSA isoforms can be used to better predict prostate cancer risk. Higher rate of free PSA illustrate lower risk of prostate cancer. Prostate Health Index (PHI) can be used to predict probability of finding cancer, poor prostatectomy outcomes and progression during surveillance. 4K score (consisting of total PSA, free PSA, intact PSA, and hK2) has shown improved specificity for finding clinically significant prostate cancer on biopsy. Urinary markers can also be used. PCA3 has been approved by FDA but only for recommendation for a repeat biopsy. These urinary markers need head-to-head comparative studies.
Numerious nomograms can combine several clinical variables to assist in clinical decisions. These combine life expectancy, comorbidities, prostate volume, family history, race and prior biopsy history.
In conclusion, improving care of prostate cancer involves better patient selection (selecting those with long life expectancy), better screening (baseline PSA in 40’s, using more specific markers, using risk-adapted nomograms), better biopsy (reducing infection risk and increasing the yield of a positive biopsy using imaging such as mpMRI), and better treatment (more active surveillance for low-risk and reducing treatment-related morbidity). A balanced approach is needed . In Pre-PSA era, we had increased metastatic disease incidence and increased prostate cancer deaths. In PSA-era we have increased inappropriate testing and wide-spread overtreatment. In future, we need more balanced screening with selective, personalized risk-adapted strategies.
Presented By: Stacy Loeb, MD