The best indicator of recurrence is the prostate specific antigen (PSA) blood test. PSA is a protein produced by normal prostate and prostate cancer cells. It is found in the blood in higher amounts than normal when cancer is present (see Mr PHIP No. 2). It is a very good indicator of whether living cancer cells remain following surgery or radiotherapy. The meaning of the test result differs depending on which treatment you had.
Monitoring after surgery
Since PSA is produced by both normal and cancer cells in the prostate, if all prostate cells have been removed at the operation, then the level of PSA ought to fall to an undetectable level, or less than 0.1 ng/mL. The time taken for the PSA to drop to this level after surgery depends on how high it was before the operation; in most cases, it should be undetectable at 3 months after surgery.
Most surgeons recommend a PSA test every 3–4 months after surgery for the first 2 years and then 4–6 monthly for 2–5 years. After this, the risk of the prostate cancer returning is small. Annual testing is often then recommended.
Your doctor may suggest a different testing program. It depends on the nature of your cancer (see Mr PHIP No. 3).