Early warning: PSA testing can predict advanced prostate cancer

Researchers who showed that a single prostate specific antigen (PSA) test at age 50 or under could predict the presence of prostate cancer up to 25 years later, (regardless of clinical significance) have now found that a single PSA can be used to predict advanced prostate cancer.

The findings, published in the online open access journal BMC Medicine, should help physicians identify which men would benefit from intensive screening.

More men die with prostate cancer than from it and in many cases the quality or length of their lives are not affected. However, advanced prostate cancer has serious consequences, including death. Researchers from Memorial Sloan-Kettering Cancer Center, New York and Lund University, Sweden set out to investigate the ability of a single PSA test to predict a diagnosis of advanced prostate cancer in later life. Advanced cancer was defined as one where the cancer had spread locally beyond the prostate or to other parts of the body at the time of diagnosis.

The team studied blood samples collected between 1974 and 1986 as part of a large population-based study of middle-aged men. The study cohort included 161 men who had been diagnosed with advanced prostate cancer by 1999 and men of a similar age who had not developed cancer by that time. The results showed that the total PSA level was an accurate predictor of advanced cancer diagnosis in later life. The majority (66%) of advanced cancers were seen in men whose PSA levels were in the top 20% (total PSA > 0.9 ng/ml). The median time from blood test to cancer diagnosis was 17 years.

The authors write: “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.”

Targeting screening could allow physicians to intervene when the cancer is at an early stage and still curable. It could also reduce ‘overdiagnosis’ and unnecessary treatment in men with benign tumours.