Clinical Information

Do not predict disease recurrence solely on serial PSA values. Do not interpret levels of PSA as absolute evidence of the presence or the absence of malignant disease. Digital rectal examination generally does not increase normal prostate-specific antigen (PSA) values. However, cystoscopy, urethral instrumentation, and prostate biopsy may increase PSA levels. This assay is intended to be used as an aid in the detection of prostate cancer and as an aid in the management (monitoring) of prostate cancer patients, in accordance with current clinical practice guidelines. Specimens obtained from patients undergoing prostate manipulation, especially needle biopsy and transurethral resection, may show erroneously high results. Prostate cancer patients under treatment with anti-androgens and LHRH agonists may exhibit markedly reduced levels of PSA. Also, men treated for benign prostatic hyperplasia with inhibitors of 5α‑reductase (finasteride) may demonstrate a significant reduction in PSA levels compared to values prior to treatment. 
For assays employing antibodies, the possibility exists for interference by human anti-animal antibodies (i.e., heterophile antibodies) in the patient sample. Patients who have been regularly exposed to animals or have received immunotherapy or diagnostic procedures utilizing immunoglobulins or immunoglobulin fragments may produce antibodies, (eg, HAMA), that interfere with immunoassays. This may falsely elevate or falsely decrease the results. Free PSA testing is sent to Mayo Clinic Laboratory.