biochemical relapse

Definition of biochemical relapse
National Cancer Institute

biochemical relapse

(BY-oh-KEH-mih-kul REE-laps)
A rise in the blood level of PSA (prostate-specific antigen) in prostate cancer patients after treatment with surgery or radiation. Biochemical relapse may occur in patients who do not have symptoms. It may mean that the cancer has come back. Also called biochemical recurrence and PSA failure.

Source: NCI Dictionary of Cancer Terms