PSA persistence or recurrence may occur after you've been treated for localized prostate cancer. Usually the level of PSA in the blood drops very low after radiation therapy or surgery to remove the prostate. But this doesn't always happen.

• Sometimes, the PSA level doesn't drop as much as expected. This is called PSA persistence.
• Sometimes after falling very low, the PSA level starts rising. This is called PSA recurrence.

If your PSA level persists or rises after treatment, you may have tests to see if the cancer is still there, has come back (recurrence), or has spread to other parts of your body (metastasis). You may need treatment, even if the cancer hasn't spread. Or you may be able to delay treatment until tests show that you are likely to develop symptoms. Treatment is based on what kind of treatment you had before.