This article was originally published here
BJU Int. 2021 Apr 3. doi: 10.1111/bju.15417. Online ahead of print.
OBJECTIVES: To explore if there is a long-term association between baseline prostate-specific antigen (PSA), including free/total PSA ratio and long-term (30 years) risk for prostate cancer death.
SUBJECTS AND METHODS: In all, 1782 men were screened for prostate cancer through PSA analysis. Some years later, frozen plasma samples were used to calculate the ratio of free-to-total PSA (f/t PSA). At 30 years of follow-up, baseline PSA and f/t PSA were compared with recent data extracts from the Swedish Cause of Death Registry and Swedish Cancer Registry. PSA values and f/t PSA values were treated as continuous variables in a multivariable analysis and also stratified according to their distribution and useful clinical cut-points.
RESULTS: Risk of death from prostate cancer at 30 years of follow-up was significantly increased with a higher baseline PSA, with hazard ratio being 1.04 (1.03-1.09) per increase of one unit of PSA. Adding f/t PSA increased the model’s ability to discriminate (concordance-index 0.84 to 0.88). Men with PSA<1 ng/mL had a very low long-term risk for prostate cancer death (1.2% risk). F/t PSA≥0.25 extended the low-risk range to PSA<2 ng/mL (1.5% risk).
CONCLUSION: PSA testing can be done less frequent or discontinued in men aged 55-70 years if PSA is <2 ng/mL and f/t PSA is ≥0.25.