[PSA in the staging and monitoring of cancer of the prostate].
The prostatic surface antigen (PSA), exclusively secreted by the prostatic epithelial cells, can be raised in the sera of patients with various prostatic pathologies. Serum levels of this marker depend on many factors (prostatic manipulation, associated inflammation, volume of benign node hyperplasia, volume and grading of tumour differentiation), all of which will have to be taken into account when interpreting any specific level. The usefulness of this antigen has a distinctive role in the suspected diagnosis, staging and monitoring following treatment of prostate cancer. PSA has shown to be more effective than other markers in the diagnosis of prostate cancer. Following the review of 106 patients with prostate cancer in various clinical stages, PSA was higher in 76.5% and PAP only in 49%. There is also a correlation between PSA and the extension of the disease. Of 43 patients surgically (stages B, C, D1) or radiologically (stages D2) staged, increases PSA has been found in 25% B stages, 77.7% C stages and 88.4% D stages. With regard to post-treatment monitoring, PSA is highly useful to determine its effectiveness, detect any residual illness and predict a recurrence or progression.