onthefence said...
Doesn't the Gleason score distinguish the aggressive cancers from the indolent ones?
I think that Dr Steven Strum provides an excellent description at the prostate-cancer.org site:
Slow-growing variants in general, have low PSA values (under 10) and long doubling times (greater than 24 months and often 48 months or longer), as well as low PSA velocities (<0.75 ng/ml/yr ± 10%). If a biopsy is done on a patient with a PSA that is under 10, the Gleason score often turns out to be (3,3). Depending on the calculated tumor volume, clinical stage, PSA doubling time, and other factors, these objectified biologic parameters may allow many such patients to be candidates for AS.
Aggressive variants, in general, have high PSAs (over 10) OR very low PSAs associated with very aggressive, high Gleason score [(4,3), (4,4), (4,5), (5,4), (5,5)] cancers. These variants (low PSAs) are very dangerous, often escaping investigation for long periods of time because the PSAs appear to be in the so-called normal range. High Gleason score cancers often have reverted to an embryonic state in which PSA secretion into the blood is markedly reduced.
Checking the serum for abnormal elevations in markers such as CGA (Chromogranin A), NSE (Neuron Specific Enolase), CEA (Carcino- Embryonic Antigen) and PAP (Prostatic Acid Phosphatase) is important to discern PC activity secondary to these de-differentiated tumor cell populations. Therefore, in cases such as this, the normal guidelines for PSA velocity and doubling time may not be applicable. HOWEVER, the concept of slope or trend in a biomarker of disease activity remains valid, and any biomarker elevation should be tracked at regular intervals to determine the presence of abnormal growth of primitive (embryonic) tumor cell clones.
Inherent in this perpsective is that
nobody should be making a determiniation based on just
one test...