Doctors are concerned about two things coming back from a PSA blood test:

1. The absolute level, and

2. The "PSA velocity" - the rate of change from one annual PSA test to the next over a set period of time, say a year.

A PSA result above 3.0 ng/mL, if the patient has a history of being below 3.0 ng/mL, (and especially if the patient had a history when younger of having a PSA below 1) might cause a MD to recommend a biopsy. A digital rectal examination won't tell much more than the PSA will, ie, "there's something we should check out more." There are also additional lab tests for prostate cancer, including the "Phi test" (which measures specific fractions of PSA in your blood), the "PCA3" urine test, looking for a gene specific to prostate cancer, and the "4KScore" test, which measures total/free/intact PSA and enzymes in the blood, which is fed through a predictive algorithm to project your likelihood of having an aggressive cancer of the prostate.

Now, as to PSA velocity: "PSA Velocity" is about how much your PSA levels have changed since the previous test(s).

A change in PSA of 0.75 ng/mL in a year when your total PSA is 4.0 to 10.0 ng/mL is taken as an early indicator of a potential cancer.

A change of 2.0 ng/mL in a year shows an elevated likelihood of developing an aggressive cancer of the prostate.