Distribution of prostate specific antigen (PSA) and percentage free PSA in a contemporary screening cohort with no evidence of prostate cancer

Abstract

%f/tPSA analyses were repeated for each age category after excluding, respectively, the top and the bottom 10% of PSA and %f/tPSA values. RESULTSWithin the entire cohort, the median PSA level was 1.0 ng/mL and the median %f/tPSA was 25%. According to the age categories the PSA level and %f/tPSA medians within the entire cohort were, respectively, 0.7, 0.9, 1.3, 1.8 ng/ mL and 28.0, 26.0, 24.0 and 25.0%. Of the 2323 men, 438 (18.9%) had a PSA level of > 2.5 ng/mL and 1172 (50.5%) had a %f/tPSA of ≤ 25%. When either a PSA level of > 2.5 ng/ mL or a %f/tPSA of ≤ 25% were considered, 1235 (53.2%) had one or two abnormal values. Finally, if either a PSA level of > 2.5 ng/ mL or %f/tPSA of ≤ 15% was used, 617 (26.6%) were considered abnormal. CONCLUSIONHalf of men with no clinical evidence of prostate cancer should have PSA levels of < 1.0 ng/mL and a %f/tPSA of > 25%. A PSA level threshold of 2.5 ng/mL would require a biopsy in 20% of men and a %f/tPSA threshold of ≤ 25% in half of the men. Alternatively, a %f/tPSA threshold of ≤ 15% would decrease the probability to 15%.

Major inter-laboratory variations in PSA testing practices: results from national surveys in Ireland in 2006 and 2007

“…In an attempt to increase specificity other indices (such as fPSA) have been employed. FPSA has been shown to increase the specificity of tPSA to detect prostate cancer while decreasing the number of unnecessary biopsies performed in men with marginally elevated tPSA [18][19][20]. However, in our survey fPSA was measured in only one-third of the laboratories that measure tPSA.…”

The association between metabolic syndrome and prostate‐specific antigen levels

“…Remarkable increases in the incidence of prostate cancer were noted in the early 1990s in many countries, largely due to the widespread use of prostate‐specific antigen (PSA) testing. The high tissue specificity of PSA makes it one of the most useful tumor markers in medicine, facilitating diagnosis, staging, and monitoring of prostatic disease and treatment; yet PSA levels may be affected by many factors, such as age, prostate volume, and obesity 1–9 . With the introduction of PSA testing in prostate cancer screening programs, the sensitivity of PSA has been questioned.…”

Prostate Cancer and Metabolic Syndrome: Is there a link?

“…A randomized European study showed that PSA-based screening reduced the rate of death from prostate cancer by 20% (Schröder et al, 2005). The PSA levels may be affected by factors such as age, prostate volume and obesity, and the sensitivity and specificity of the PSA test has been questioned (Freedland et al, 2006;Kim et al, 2007;Chun et al, 2007). Approximately 1.5 million American men ages 40 to 69 years have PSA levels of > 4.0 ng/mL, a widely used cut-off value for a positive screening result (Schröder et al, 2005).…”