[PSA kinetics after total prostatectomy]. / Cinétique du PSA après prostatectomie totale.

ABSTRACT

The prostate specific antigen (PSA) is the best marker of the prostate cancer today although not very specific of this pathology. The dynamic interpretation of this marker always has to prevail over that of overtaking a threshold. With the lack of residual cancer, PSA becomes undetectable by the first month after total prostatectomy less than 0.1 microg/L. The type of diminution mono- or biphasic of the marker depends on the chronology of the takings. Faced with residual cancer, PSA either does not become undetectable or increases after an initial undetectable period. A recurrence is defined by a value of PSA higher than 0.2 microg/L and confirmed on two successive assays. The time of appearance of the recurrence and the PSA doubling time after total prostatectomy have, with the initial clinical stage and the Gleason score, a diagnostic value on the nature of the site of recurrence, local or metastatic.