Prostate Cancer Research Today is a free monthly online journal that collates and summarizes the latest research about Prostate Cancer, including details on symptoms, genetics, screening, treatment, information. | ||||||||
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Long-term prediction of prostate cancer: prostate-specific antigen (PSA) velocity is predictive but does not improve the predictive accuracy of a single PSA measurement 15 years or more before cancer diagnosis in a large, representative, unscreened population.Ulmert D, Serio AM, O'Brien MF, Becker C, Eastham JA, Scardino PT, Björk T, Berglund G, Vickers AJ, Lilja H Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. PURPOSE: We tested whether total prostate-specific antigen velocity (tPSAv) improves accuracy of a model using PSA level to predict long-term risk of prostate cancer diagnosis. METHODS: During 1974 to 1986 in a preventive medicine study in Sweden, 5,722 men aged <or= 50 gave two blood samples about 6 years apart. We measured free (fPSA) and total PSA (tPSA) in archived plasma samples from 4,907 participants. Prostate cancer was subsequently diagnosed in 443 (9%) men. Cox proportional hazards regression was used to evaluate tPSA and tPSAv as predictors of prostate cancer. Predictive accuracy was assessed by the concordance index. RESULTS: The median time from second blood draw to cancer diagnosis was 16 years; median follow-up for men without prostate cancer was 21 years. In univariate models, tPSA level at second assessment and tPSAv between first and second assessments were associated with prostate cancer (both P < .001). tPSAv was highly correlated with tPSA level (r = 0.93). Twenty-year probabilities of cancer for men at 50th, 90th, and 95th percentile of tPSA and tPSAv were 10.6%, 17.1%, and 21.2% for tPSA, and 9.1%, 11.8%, and 14.1% for tPSAv, respectively. The concordance index for tPSA level was 0.771. Adding tPSAv, fPSA, %fPSA or velocities of fPSA and %fPSA did not importantly increase accuracy of tPSA to predict prostate cancer. Results were unchanged if the analysis was restricted to patients with advanced cancer at diagnosis. CONCLUSION: Although PSA velocity is significantly increased in men with prostate cancer up to two decades before diagnosis, it does not aid long-term prediction of prostate cancer. Published 18 February 2008 in J Clin Oncol, 26(6): 835-41.
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