Prostate
specific antigen (PSA) test
A
small sample of blood is taken from a vein in your arm and sent
to the laboratory to measure the level of PSA. This is made in
the prostate and may leak into your bloodstream if you have prostate
cancer.
Normally
men with no cancer will have a PSA level of less than 4 micrograms
per litre.
One
in three men with a PSA level between 4 and 70 micrograms per
litre will
have cancer.
There
are various reasons for a raised PSA level. A high PSA does not
necessarily mean cancer is present nor does a lower level always
mean it is absent. It is generally felt that the PSA test is not
accurate enough to be used to screen every man.
