If the PSA rises and continues to rise, this normally indicates a return of the cancer.
On rare occasions, the rise may be due to growth of benign prostate cells, inflammation or infection within the prostate. Other non-cancer treatments may be appropriate.
The way the PSA changes is important. A steady continued increase is likely to prompt the doctor to suggest further treatment to control the cancer (often hormone treatment). Tests to try to identify where the prostate cancer cells are in the body may not be helpful until the PSA is over 20 ng/mL, because the scans do not pick up small groups of cells.