Jg. Masters et al., FREE TOTAL SERUM PROSTATE-SPECIFIC ANTIGEN RATIO - HOW HELPFUL IS IT IN DETECTING PROSTATE-CANCER/, British Journal of Urology, 81(3), 1998, pp. 419-423
Objective To determine whether the use of free/total (f/t) serum prost
ate specific antigen (PSA) ratio would help reduce the number of prost
ate biopsies performed without compromising the detection of prostate
cancer, in the setting of a transrectal ultrasonography (TRUS) clinic.
Patients and methods The study included 93 consecutive patients refer
red to the clinic for TRUS and biopsy, Serum samples were assessed for
total PSA and free PSA, and the fit PSA ratio calculated; 70 biopsies
were taken. Patients over the age of 70 years with TRUS findings cons
istent with benign prostatic hyperplasia and with PSA levels <10 ng/mL
were not biopsied. Results Tumour was detected in 23 patients; receiv
er operating characteristic curves showed no advantage for the fit PSA
ratio when compared with total PSA in detecting prostate cancer, If a
fit PSA ratio of < 0.15 had been used to determine the necessity for
biopsy in the group with a total PSA of 4-10 ng/mL, then two-thirds of
all tumours would have been undetected. Conclusion The fit PSA ratio
had no advantage over total PSA in improving specificity at a given se
nsitivity for detecting prostate cancer, Therefore, it cannot be recom
mended as a means of decreasing unnecessary biopsies in patients with
a raised PSA level and/or an abnormal digital rectal examination. This
applied particularly to the group of patients with a total PSA of 4-1
0 ng/mL.