The most commonly used tumor markers with enzymatic activity are:
- Prostate-specific antigen (PSA)
- Prostatic acid phosphatase (PAP)
- Alkaline phosphatase
- Neuron-specific enolase
While PAP was used for many decades as a screening tool and has utility in staging prostate cancer, elevated PAP is also associated with cancers of the bone and bone marrow, and also in benign conditions of not only the prostate, but the bones and parathyroid.
Among these most common enzymatic tumor markers, only PSA is specific or sensitive enough to identify specific organ involvement related to cancer.
On the following slides, the biochemistry and clinical applications of PSA will be discussed in greater detail.