Cumulative prostate cancer risk assessment with the aid of the free-to-total prostate specific antigen ratio.

OBJECTIVE: To evaluate the cumulative risk of having a prostate cancer diagnosis in a repeated screening situation in relation to the free-to-total prostate specific antigen ratio (F/T-PSA). PATIENTS AND METHODS: The present study includes 1385 men (aged 50-70 years) who underwent prostate biopsy for the first time in the screening program that started in 1995. In case of a benign finding, the men have been followed biennially and new biopsies performed in case of persistently elevated PSA. The cumulative risk to be diagnosed with prostate cancer until July 1, 2002 was calculated by the Kaplan-Meier method and comparison was made between different levels of T-PSA and F/T-PSA ratios. RESULTS: Of 2129 biopsies 469 showed cancer. The cumulative 5-year risk to be diagnosed with prostate cancer was significantly dependent of the F/T-ratio. The risk for men with a T-PSA of 3-5.99 g/ml was 16% [6-25%] for those who had a ratio of >30% and 44% [34-60%] for those with a ratio of <10%. The corresponding difference for patients with a T-PSA of 6-9.99 g/ml was even more pronounced: 21% [0-42%] vs. 80% [64-96%]. CONCLUSION: By completing the T-PSA measurement with the F/T-PSA ratio it is possible to significantly better assess the cumulative prostate cancer risk within the next five years (without the aid of further urological work-up).