Updated Guidelines for Surviving Prostate Cancer

Prostate cancer is the second-leading cause of cancer death among men in the United States. During 2002, approximately 189,000 new cases of prostate cancer were diagnosed in the United States, and over 32,000 American men died of this terrible disease. A man has a one in six chance (15.4%) of developing invasive prostate cancer during his lifetime, though it is clear that the risk increases with age. From birth to age 30, the chances are 1:10,000; from age 40 to 59, the chances are 1:103; from age 60 to 79, the chances are 1:8.  At the age of 50, a man has a 42 percent chance of developing prostate cancer, a 2.9 percent chance of dying from the disease.

The incidence of prostate cancer has increased dramatically worldwide over the past ten years. In the United States for example, the age-adjusted incidence has increased from 84.4/100,000 in 1984 to 163/100,000 in 1991.  Most of this increase may be attributed to the increase of early detection programs based on the prostate specific antigen (PSA). As a result of new screening techniques, an increased incidence of disease is to be expected. A subsequent decrease in the incidence is also to be expected as prevalent cases of a disease process are removed from the population.

What is Prostate-Specific Antigen (PSA)?

Prostate specific antigen (PSA) is a glycoprotein produced primarily by cells in the prostate gland.  Men who have prostate cancer frequently have high or abnormal PSA levels due to the enhanced production of PSA and various changes in the size and shape of the prostate that allow the PSA greater access to the circulatory system.  Therefore, the amount of PSA in the blood can serve as a marker for prostate cancer.  In addition, an elevated PSA level can indicate such conditions or events as biopsy of the prostate, transrectal prostatectomy, acute urinary retention, acute and chronic prostatitis, ejaculation, and benign prostatic hyperplasia.  The test measures total PSA, and the results are reported in nanograms per milliliter (ng/ml).

Despite the wide use of the PSA test in the detection and monitoring of prostate cancer, its sensitivity and specificity are quite low.  The ideal blood test would be 100 percent sensitive - that is, it would detect all cancer in a group of men with no false negatives.  It would also be 100 percent specific - that is, it would not diagnose cancer when none exists.  Unfortunately, the PSA test sometimes produces false negatives and false positives.

Identifying the PSA Origin

In 1970, Ablin et al. were the first to identify the prostate specific antigen.  Shortly thereafter, Hara et al. identified and confirmed PSA in the seminal fluid.  In 1973, Li and Beling purified the PSA in seminal fluid.  Eight years after the identification of PSA by Ablin et al., Sensabaugh and Crim confirmed that seminal fluid and the prostate gland had common antigens and that the origin was the prostate.  It didn’t take long for Wang et al. to isolate and purify the PSA from tissue of the prostate gland.  Finally, in 1980, Papsidero et al. located PSA in the blood.

In 1986, the U.S. Food and Drug Administration (FDA) approved two uses for the PSA test: (1) determining if treatment for prostate cancer had eliminated all of the diseased tissue and (2) monitoring a patient for a recurrence of the disease.  In 1994, the FDA approved the use of the PSA test for detecting prostate cancer.  Today the PSA test is used for:

estimating the time to clinical failure after treatment

calculating the rate of change in a patient’s cancer cell load

estimating a patient’s pathological stage and lymph-node involvement

monitoring for a recurrence of prostate cancer

separating patients with benign prostatic hyperplasia