(UroToday.com) The 2024 European Association of Urology (EAU) annual meeting featured a game changing session for guideline changes in screening and diagnosis for prostate cancer, and a presentation by Dr. Peter Albers discussing insights from the PROBASE trial. “Smart screening” for prostate cancer may include an assessment of age and family history followed by a PSA + a biomarker, followed by an MRI, followed by an MRI-guided biopsy:
Where the PROBASE trial fits in is in the assessment of age. There are several challenges in risk-adjusted PSA-based prostate cancer screening, such as:
- At what age should a baseline PSA be obtained?
- What is defined as “low risk”?
- How often should testing take place?
A previously delineated European model for an organized risk-stratified early detection program for prostate cancer suggested only a PSA < 1.0 ng/mL is considered as low-risk, that screening should start at 50 years of age, and patients should be re-screened at 5 years. Based on the 2024 EAU guidelines, a PSA < 1.0 ng/mL at age 40 is suggestive of low risk, and that patient should be rescreened at 8 years.
PROBASE is a German prospective multicenter randomized, risk-adapted prostate cancer early detection study based on a “baseline” PSA value in young men. This trial started in 2014 and will be finished in 2034, enrolling more than 46,000 men. All men receive a baseline PSA at 45 or 50 years of age, with the following downstream surveillance algorithm:
- PSA < 1.5 ng/mL PSA in 5 years
- PSA 1.5-2.99 ng/mL PSA in 2 years
- PSA >= 3 ng/mL repeat PSA in 2 weeks, if PSA >= 3 ng/mL MRI + biopsy
Low risk is defined as a PSA < 1.5 ng/mL based on studies suggesting that an initial PSA level < 1.5 ng/mL predicts men with low risk of harboring or developing prostate cancer. Thus far, in the PROBASE immediate screening arm (baseline PSA measured at age 45), 20,816 men had a baseline PSA of 0 – 1.49 ng/mL, with 14,248 (78%) receiving their next PSA in 5 years; we await the data for the next PSA in 10 years. In the intermediate risk group with a baseline PSA of 1.5-2.99 ng/mL, this included 2,291 men, of which 1,996 (87.1%) had their next PSA in 2 years, and 1,598 men (73.5%) had their next PSA in 4 years; we await the data for the next PSA in 6 years. “Low risk” in the average risk 45-year old population in PROBASE had a median PSA of 0.74 ng/mL (range 0.01 – 24.28 ng/mL), with the current EAU guideline proposed low risk of a PSA < 1.0 ng/mL encompassing 16,528 (71%) of men in PROBASE. “PROBASE low risk” of a PSA < 1.5 ng/mL encompasses 89% of men in PROBASE, who would get their next screening PSA in 5 years:
Furthermore, men with a PSA >= 3 ng/mL (high risk) after 5 years is as follows:
With regards to men with prostate cancer after 5 years, there have been 65 cases, of which 49 (75%) had a screening PSA of >= 2.0 ng/mL:
The following figure summarizes the findings of a PSA cut-off to define “low-risk” at age 45, specifically highlighting that no prostate cancer was observed so far in men with baseline PSA < 0.5 ng/mL:
Dr. Albers concluded his presentation discussing insights from the PROBASE trial by emphasizing that men at 45 years of age with a baseline PSA < 1.5 ng/mL are at very low risk of developing prostate cancer within the next five years.
Presented by: Professor Peter Albers, MD, Düsseldorf University and German Cancer Research Center, Düsseldorf, Germany
Written by: Zachary Klaassen, MD, MSc - Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, WellStar MCG Health, @zklaassen_md on Twitter during the 2024 European Association of Urology (EAU) annual congress, Paris, France, April 5th - April 8th, 2024