Prostate Specific Antigen (PSA)
PSA is a protein that is made by the prostate and is found in semen. A small amount leaks in to the blood stream in all men. Some conditions increase the amount of PSA that leaks into the blood stream; serum PSA increases in men who have a large prostate, with urinary tract infection and men who have prostate cancer.
The decision to have a PSA blood test is a personal one. Opinion within the medical profession is divided about who should have a PSA blood test. Some doctors think that PSA gives us the best available chance to reduce the number of men who die of prostate cancer each year - currently nearly 11000. Other doctors think that having a PSA blood test will cause many men to have tests and treatments from which they will not derive any benefit.
The PSA blood test does not say for sure if a man has prostate cancer - this usually requires further investigation after referral to a consultant urologist - usually MRI of the prostate, followed by a biopsy.