(UroToday.com) The 2024 SUO annual meeting included a prostate cancer session, featuring a late breaking abstract presentation by Dr. Tobias Nordstrom discussing the STHLM3 trial and biochemical recurrence after radical prostatectomy and whether we are missing aggressive prostate cancer with PSA screening alone.
PSA is used for prostate cancer screening with various thresholds, however aggressive cancers may be present with lower PSA values, while other prostate cancer detected above certain thresholds (ie. 3 ng/ml) may not be as aggressive. At the 2024 SUO annual meeting, Dr. Nordstrom and colleagues presented results of their assessment of long-term recurrence of cancers detected above or below clinical thresholds of PSA and Stockholm3.
In more detail, Stockholm3 is a blood test with a proprietary algorithm delivering an integer risk score and binary recommendation:
Stockholm3 has been evaluated in population based randomized controlled trials in Sweden that that detects clinically significant prostate cancer in low PSA while reducing the overdiagnosis and over testing:
Participants were captured from the STHLM3 trial (ISRCTN84445406),1 a population-based paired diagnostic screening by invitation trial which included 58,818 men (2012-2014). Men underwent diagnostic screening test with PSA, and if the PSA was ≥1 ng/ml, a multi-analyte Stockholm3 blood test, which includes plasma protein markers, germline polygenic risk, and clinical variables was obtained. Men with PSA ≥3 ng/ml or Stockholm3 ≥11 were recommended to undergo prostate biopsy. The primary outcome measure was biochemical recurrence after radical prostatectomy. All men that underwent radical prostatectomy within 12 months of diagnostic test and without PSA persistence (within 3 months) after radical prostatectomy were included (n = 785).
The median follow-up in this analysis was 7.1 years (IQR: 5.2–7.1), the median age was 64 years (IQR: 59-67), the median PSA was 4.3 ng/mL (IQR: 3.2-6.6), and 11% of men had biochemical recurrence at 5 years. The 5-year biochemical recurrence rates were (p < 0.001):
- 15% for elevated Stockholm3 (>11) and PSA (>3 ng/ml)
- 10% for elevated Stockholm3 alone
- 0.9% for elevated PSA alone
- 0% for non-elevated results on bothw
Compared to the reference group (elevated Stockholm3 alone) for biochemical recurrence, men with elevated PSA alone was HR 0.22 (95% CI: 0.06-0.81; p = 0.020) while men with elevated Stockholm3 and elevated PSA was HR 1.95 (1.02- 3.75; p = 0.045).
Dr. Nordstrom concluded his presentation discussing the STHLM3 trial and biochemical recurrence after radical prostatectomy and whether we are missing aggressive prostate cancer with PSA screening alone with the following take home messages:
- Some men with low PSA levels have clinically significant prostate cancer
- Prostate cancer detected with an elevated Stockholm3 below a PSA threshold of 3 ng/mL have a risk of biochemical recurrence after curative therapy
- It is unknown the natural course of men that harbor clinically significant prostate cancer below a threshold of 3 ng/mL, however this data suggests these cancers may benefit from earlier treatment before conventional PSA triggers
Presented by: Tobias Nordstrom, Consultant Urologist, Karolinska Institutet, Stockholm, Sweden
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 Society of Urologic Oncology (SUO) Annual Meeting, Dallas, TX, Tues, Dec 3 – Fri, Dec 6, 2024.
References:
- Eklund M, Jaderling F, Discacciati, et al. MRI-targeted or standard biopsy in prostate cancer. N Engl J Med. 2021 Sep 2;385(10)908-920.