Value of baseline PSA in predicting prostate cancer diagnosis and death. Spanish arm of the European Randomized Study of Screening for Prostate Cancer.

Introduction: Several studies have suggested that prostate-specific antigen (PSA) in young men may predict the risk of developing prostate cancer (PC). Our aim is to study baseline PSA as a prognostic factor in the lifetime risk of developing PC, clinically significant PC (csPC), and metastatic PC (mPC), as well as to assess its impact on long-term mortality. Material and methods: This study was a retrospective analysis involving 2,415 men aged 45-70 years, all participants in the Spanish arm of the European Randomized Study of Screening for Prostate Cancer (ERSPC). These men underwent PSA testing, and prostate biopsies were performed if their PSA levels were ≥3 ng/ml. The follow-up period spanned from September 2, 1996, to February 11, 2021. Kaplan-Meier survival analysis was conducted to calculate the probability of prostate cancer diagnosis and death. The relationship between these probabilities and baseline PSA levels was assessed using the log-rank test. Results: After 25 years of follow-up, the probability of being free of a diagnosis of PC was 95.5%, 89.6%, 80.0%, and 69.4%; and of PC death: 99.6%, 99.6%, 98.9%, and 98.3% for the categories of PSA <1 ng/ml, 1-1.9 ng/ml, 2-2.9 ng/ml, and >3 ng/ml, respectively. There is an association between baseline PSA level and the probability of PC diagnosis (which is maintained in age stratification), csPC, mPC (p <0.001), and PC death (p = 0.047). Conclusions: There is a clear relationship between baseline PSA and the probability of detection of PC, csPC and mPC during follow-up, as well as PC death, in a cohort belonging to the Spanish branch of the ERSPC, with a median follow-up of more than 23 years. Baseline PSA level can be used to define the most appropriate PC screening interval for everyone.