When evaluating PSA results, the doctor must also take into account the results of the rectal exam, the patient's age, previous PSA results, and prostatic size. For example, findings on a rectal exam must be looked into even if the PSA result is normal.
Recent studies have suggested that the 4.0 level may be too high for younger men and too low for older men. Many researchers now use the following levels rather than the 4.0 used in the past. However, more time is needed to assure that these levels are more accurate.
If the rectal exam is normal then the following recommendations are suggested:
If previous PSA values are available, test results will be evaluated differently. The PSA level almost always rises if cancer is growing. Any PSA level that is rising is suspicious. However, a high PSA level may not mean that cancer is present. For example, a male with a stable PSA of 8 over a three-year period (8,8,8) is probably at less risk than a male with a PSA of 2, 4, and 6 over the same time frame. This is because the second patient's rising levels suggest growth. This makes it suspicious for cancer. If the first patient had a negative biopsy when the first high PSA value occurred, there may be no need to repeat the biopsies. If the PSA level jumped to 10 or 15 for no apparent reason, then repeat ultrasound and biopsies would be called for. Recent studies suggest that either a 20% rise or a measurable rise of 0.75 in PSA in one year should prompt a closer look. Ultrasound and biopsy may be needed.