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Rapid response to:

Research

Prostate specific antigen for early detection of prostate cancer: longitudinal study

BMJ 2009; 339 doi: https://doi.org/10.1136/bmj.b3537 (Published 24 September 2009) Cite this as: BMJ 2009;339:b3537

Rapid Response:

Screening PSA Results Should be Followed by Free PSA/PSA Ratio

The results confirm the expectation that as the cutoff level
increases from 3 to 5 ng/ml, the sensitivity decreases and specificity
increases. Assays for free PSA [fPSA] and a resultant calculation of a
fPSA/PSA ratio have been available since the early 1990s and are useful in
further discriminating, albeit not providing an absolute distinction,
between ca & BPH in individuals with PSA results between 4 to 10
ng/ml. The study populations would've been very suitable for confirming
the utility of the fPSA/PSA ratio. Numerous articles have been published
by Lilja, Stenman, Labrie, Catalona and others concerning the clinical
validity of this ratio.

Competing interests:
Former President/CEO of Medicorp Inc. of Montreal that developed assays for PSA and free PSA/PSA ratio.

Competing interests: No competing interests

25 September 2009
Dr. Elliott Block
Biomedical Consultant, Everest Associates
Boca Raton, FL 33498