Prostate-specific antigen at or before age 50 as a predictor of advanced prostate cancer diagnosed up to 25 years later: A case-control study

In 1974–1986 blood samples were obtained from a cohort of 21,277 men aged up to 50. Through 1999, 498 men were diagnosed with prostate cancer, and of these 161 had locally advanced or metastatic prostate cancers. Three controls, matched for age and date of venipuncture, were selected for each case. Conditional logistic regression was used to test associations between molecular markers and advanced cancer.Median time from venipuncture to diagnosis was 17 years. Levels of all PSA forms and hK2 were associated with case status. Total PSA was a strong and statistically significant predictor of subsequent advanced cancer (area under the curve 0.791; p < 0.0005). Two-thirds of the advanced cancer cases occurred in men with the top 20% of PSA levels (0.9 ng/ml or higher).A single PSA test taken at or before age 50 is a very strong predictor of advanced prostate cancer diagnosed up to 25 years later. This suggests the possibility of using an early PSA test to risk-stratify patients so that men at highest risk are the focus of the most intensive screening efforts.We have previously shown that a single prostate-specific antigen (PSA) measurement taken at age 50 or younger is a strong predictor of prostate cancer diagnosed up to 25 years subsequently [1]. Our study cohort was obtained from the Malm？ Preventive Medicine Study, a large, representative, population-based study on cardiovascular risk factors that took place in Malm？, Sweden from 1974 to 1986. Using a case-control design, we found that PSA levels in the archived blood plasma taken during 1974–1986 were significantly higher in men subsequently diagnosed with prostate cancer compared with matched controls. As the rate of PSA screening in Sweden during the study period was very low [2], the study constitutes a 'natural experiment' to test hypotheses about the development of prostate cancer.Our finding has several implications, most notably that a single PSA test at age 45–50 could risk-stratify the population for the i