Prostate-specific antigen: questions often asked.

In conclusion, an effective new marker for prostatic tissue has been identified and is commonly known as PSA. A review of the literature indicates that although PSA is not tumor specific, its organ-site and cell-type specificity provide the basis for making PSA the marker of choice for use in patients with prostate cancer. The clinical utility of PSA includes monitoring therapeutic efficacy, screening and early diagnosis in high-risk patients, prognosis, staging, and tumor volume evaluation, prediction of disease progression, detection of recurrent disease after radical prostatectomy, and the differential diagnosis and confirmation of tissue for prostatic origin. PSA is not a "magic bullet" for patients with prostate cancer. Many questions must still be answered. For example, with an increase in sensitivity for screening of high-risk populations, how does the urologist/oncologist determine which patients with latent curable early cancer will develop into clinically significant metastasis? Is PSA a more reliable method for detection of early prostate cancer than rectal examination? What procedure should be followed for an asymptomatic patient who presents a 35 ng/ml level of PSA during a routine physical examination? Clearly, further studies are required to answer these questions as well as to assess the malignant potential of the prostatic tumor cell. For now, the combination of PSA, rectal examination, and transrectal ultrasonography guided needle biopsy would appear to be the method of choice to decrease the yearly fatalities due to cancer of the prostate.