The Importance of PSA Testing

admin | PSA Testing
10 Feb 2012

Why PSA Screening Remains an Essential Part of Physical Exams

Last fall the United States Preventive Services Task Force concluded that healthy men should no longer be routinely tested for prostate cancer using the prostate-specific antigen, or PSA, blood test because it often leads to treatments that needlessly diminish quality of life.

PSA is the only clinically-available study which can detect occult prostate cancers. It is imperative to find prostate cancers before they spread beyond the confines of the gland. The objection of the USPSTF was that it led to unnecessary treatment of prostate cancers that might not ever become life-threatening. Therefore prostate cancers that are not necessarily life threatening receive treatment that might significantly alter the quality of life. The objective is to find a treatment that does not impair quality of life, yet eliminates the tumor. If there was a treatment that could preserve the quality of life, but eradicate the tumor, PSA testing would remain useful.

Such a treatment does exist: HIFU or High Intensity Focused Ultrasound. HIFU is a treatment that provides a cure rate that is equivalent to surgery or radiation but has a minimal impact on potency and the development of post-treatment urinary incontinence. The cure rates of patients treated with HIFU when compared to radiation and radical prostatectomy are equivalent if the degree of malignancy and the clinical stage of the cancer are identical. For instance a patient who has a tumor that is confined to the prostate with no evidence of local spread or distant metastases will fair equally well with HIFU as with radical prostatectomy or radiation.

A Digital Rectal Examination or DRE that detects the presence of a prostate cancer usually infers that the cancer has spread beyond the prostate capsule and is unlikely to be curable either with surgery or with HIFU. Such a patient is best served with radiation therapy. A DRE that detects a benign-feeling gland usually implies that the tumor is confined to the gland and can be treated equally well with HIFU, radical prostatectomy or radiation. The most useful way of using PSA as a tool to detect prostate cancer is looking for PSA acceleration. When PSA became clinically available in 1990 the benchmark was 4.0.

Patients with a PSA of 4.0 or greater were two standard deviations from the mean statistically. 95% of the prostate cancers in the general population were found in patients with a PSA of greater than 4. Because of active, aggressive detection spurred on by performing prostate biopsies on patients with a PSA of 4.0 or greater over a 20-year period, the benchmark for finding 95% of the prostate cancers in the general population has dropped to 2.5. 2.5 is also the benchmark for benign prostatic hypertrophy, a non-cancerous condition. PSA, however, tends to accelerate in patients with prostate cancer, whereas PSA in patients with benign prostatic hypertrophy tend to remain static and do not increase at as rapid a rate.

If interpreted properly, based on 20 years experience, PSA does remain a useful test. It should be noted however that the only way to diagnose prostate cancer is with a prostate biopsy that demonstrates the presence of the tumor.

Indications of PSA acceleration can help detect treatable cancers and the tests should remain a part of physical examination for men over age 50. If the PSA exceeds 2 standard deviations of the means it is considered abnormal. If the PSA is less than 1.0, it needs to be repeated every other year. If it is between 1 and 2.5, it should be checked annually.

If PSA testing is no longer covered by some insurance policies, the test can still be done if the patient requests it. The point is that you must become your own prostate health advocate. Over-diagnosis leading to impaired quality of life with treatment can be overcome with HIFU treatment.

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