The method used at the Prostate Institute of America to help determine how aggressive the interventional approach should be is the comparison of actual PSA (serum PSA found in the blood) with the predictable PSA (based on the volume of the prostate gland). Through skillful use of transrectal ultrasound, an accurate measurement of the prostate gland volume allows us to calculate the predicted PSA. If the serum PSA level is lower than the predicted level, the patient is in a lower-risk group or may have low-grade/latent carcinoma.
We may not rush to biopsy to make a diagnosis at this time. Watchful waiting, with periodic PSA testing, may be adequate. However, if the serum PSA level is higher than the predicted level, the patient may be at a high-risk of having a significant tumor. In these cases, a biopsy would be performed unless other reasons for a high PSA are determined.
Careful ultrasound evaluations, including black and white and color Doppler imaging, are important to identify the size and the location of a tumor. Strategic (non-random) biopsies of the abnormal tissue and of the tissues immediately outside the prostate should be obtained to assess the exact extent of the cancer.
Diagnostic accuracy is highly dependent on the skill and experience of the physician as well as the quality of equipment. Under-staging (underestimation) the disease is the single-most common cause of selecting the wrong treatment options and as a result, leads to treatment failures.
In previous studies, we reviewed 140 men with known cancer diagnosis based on biopsies performed at other institutions that stated the cancer was confined within the prostate. All of the subjects had staging biopsies repeated by our staff. The result showed 30% of these men had cancer that was already outside of the prostate confinement. In these cases, it was necessary to reconsider the treatment options and overall cancer management.
Information provided by Dr. Duke Bahn, M.D., Medical Director of the Prostate Institute of America.