Prostate-specific antigen and long-term prediction of prostate cancer incidence and mortality in the general population.

Abstract

5 Background: It is largely unknown whether prostate-specific antigen at first date of testing predicts long-term risk of prostate cancer incidence and mortality in the general population. We tested the hypothesis that baseline prostate-specific antigen levels predict long-term risk of prostate cancer incidence and mortality. Methods: Using a prospective study, we examined 4383 20-94 year old men from the Danish general population followed in the Copenhagen City Heart Study from 1981 through 2009. Prostate-specific antigen was measured in plasma samples obtained in 1981-83. Results: During 28 years of follow-up, 170 men developed prostate cancer and 94 died from prostate cancer. Median follow-up was 18 years (range 0.5-28 years). For prostate cancer incidence, the subhazard ratio was 3.0 (95% confidence interval (CI) 1.9-4.6) for a prostate-specific antigen level of 1.01-2.00 ng/ml, 6.8 (4.2-11) for 2.01-3.00 ng/ml, 6.6 (3.4-13) for 3.01-4.00 ng/ml, 16 (10.4-25) for 4.01-10.00 ng/ml, and 57 (32-104) for >10.00 ng/ml versus 0.01-1.00 ng/ml.. For prostate cancer mortality, corresponding subhazard ratios were 2.2 (1.3-3.9), 5.1 (2.8-9.0), 4.2 (1.8-10), 7.0 (3.8-14), and 14 (6.0-32). For men with prostate-specific antigen levels of 0.01-1.00 ng/ml, absolute 10-year risk of prostate cancer was 0.6% for age <45 years, 0.7% for 45-49 years, 1.1% for 50-54 years, 1.2% for 55-59 years, 1.3% for 60-64 years, 1.1% for 65-69 years, 1.3% for 70-74 years, and 1.5% for age≥75 years; corresponding values for prostate-specific antigen levels >10.00 ng/ml were 35%, 41%, 63%, 71%, 77%, 69%, 75%, and 88%, respectively. Conclusions: Stepwise increases in prostate-specific antigen at first date of testing predicted a 3-57 fold increased risk of prostate cancer, a 2-16 fold increased risk of prostate cancer mortality, and a 35-88% absolute 10-year risk of prostate cancer in those with prostate-specific antigen levels >10.00 ng/ml. Equally important, absolute 10-year risk of prostate cancer in those with levels 0.01-1.00 ng/ml was only 0.6-1.5%.