Differential diagnosis of prostate cancer and benign prostate hyperplasia using two-dimensional electrophoresis.
Prostate specific antigen (PSA) is a protease which is characteristic of the prostate. It is widely used as a serum marker for the early diagnosis of prostate cancer (PCa). Nevertheless, for concentrations between 4 and 10 ng/mL, PSA does not enable PCa to be distinguished from benign diseases, such as benign prostate hyperplasia (BPH). In sera, the use of a ratio between free PSA (PSA uncomplexed with protease inhibitor) and total PSA (free PSA and PSA bound to alpha-1 anti-chymotrypsin) enables the "gray zone" to be reduced, but an important proportion of patients are still wrongly classed. Using two-dimensional electrophoresis, we demonstrated using 52 PCa and 40 BPH well-documented clinical cases that BPH sera show a significantly greater percentage of low-molecular-weight free PSA elements (IwPSA) than PCa sera. In our study, the use of a ratio between IwPSA and standard free PSA enables the correct diagnosis of 100% of PCa and 82.5% of BPH cases as against when 73.1% and 42.5% respectively were correctly diagnozed using the total PSA and the free/total PSA ratio. This important finding may be related to differences in the mechanism secreting PSA from the prostate into the bloodstream. We have shown how a tissue marker may be turned into a powerful tumor marker by events probably unrelated to its expression.
Charrier
J P
JP
Département Recherche et Développement, Unité Immunoessais, BioMérieux, SA, Marcy L'Etoile, France. jean-phillippe_charrier@eu.biomerieux.com
Tournel
C
C
Michel
S
S
Comby
S
S
Jolivet-Reynaud
C
C
Passagot
J
J
Dalbon
P
P
Chautard
D
D
Jolivet
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000032:analysis*; D011470:Prostatic Hyperplasia / Q000175:diagnosis* / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism
D017430:Prostate-Specific Antigen