Criteria for an "insignificant" prostate carcinoma - all of the following:
(1) PSA density < 0.15 ng/mL
(2) Gleason score on prostate biopsy <= 6
(3) presence of tumor in one or two cores out of a 6 sextant biopsies
(4) maximal involvement of a core biopsy is 50%
where:
• PSA density = (absolute PSA value) / (weight of prostatectomy specimen in grams after removal of the seminal vesicles)
• If a prostatectomy has not been done, then the volume on transrectal ultrasound could be used. It would appear that they are assuming a density of 1 g/mL, which seems low.
• I am not sure what an "absolute PSA value" is, but it would seem to consist of ignoring the "/mL" of the serum value.
• The control of units leaves something to be desired. The units should be ng/mL per mL prostate volume.
• Some urologists now take more than 6 needle biopsies, typically 6 or 7 per side. The above criteria could be modified to <= 33% of the cores (2 of 6).
A person with a clinically insignificant tumor can be managed more conservatively.