That's what Strum claims: "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."

But your score, assuming it was reliably determined, which is
questionable given your choice of therapist, is lower.

Try Google.

That is a dangerous oversimplification. Low-PSA, *large* tumors could be
neuroendocrine PCa. The way to check that is to have a series of blood
tests called CGA (chromogranin-alpha). It is "a small cell prostate
cancer or neuroendocrine cell marker; a progressive increase in CGA
indicates an aggressive clone of PC cells that often metastasizes to
nodes, liver and lungs," per the PCRI Glossary.

If "doofy" has invested in _A Primer on Prostate Cancer_, one of the
recommendations in my March 21 reply to him on the thread
"Introduction," he will find much information about CGA and
neuroendocrine PCa, starting on page 63.

Neuroendocrine PCa is rare.

Urologists, being surgeons, rarely know about such tests.

Regards,

Steve J

Hi Doofy...Back in your "Introduction" post I wrote, "The higher the
GS, the less PSA leaks from the tumor; men with high-grade disease
will sometimes have a very low PSA.  So I'm puzzled that a palpable
tumor (therefor,
significant tumor size) that is at least GS 3+4 (as Steve J pointed
out, this needs to read by a pathologist expert in PCa) is putting out
such a small amount of PSA."

Over 20 years ago it was noted that, "These studies confirm the strong
inverse correlation between Gleason grade and the PSA content of
prostate cancer" (Aihara M, Lebovitz RM, Wheeler TM, et al; Prostate
specific antigen and gleason grade: an immunohistochemical study of
prostate cancer; J Urol 151:1558-64, 1994).  Basically a normal
prostate should produce PSA =0.066 x prostate volume.  So if you have
a 40 cm^3 healthy prostate you might expect a PSA around 2.6 ng/ml.
This "formula" is just an  empirical generalization of clinical
experience, some docs use 0.1 in place of 0.066, but there is a lot of
plus and minus.  Once PCa has been diagnosed, any PSA beyond 2.6 would
be ascribed to excess PSA generated by the tumor.  The above-
referenced paper also contained the following table that relates tumor
volume and tumor Gleason score to the "excess" PSA produced.

Table 1: PSA Leak vs Weighted Gleason Grade
Gleason Grade (Weighted)        PSA leak Rounded Off (exact)
5                                                       1    (0.93)
4.5                                                    1.5 (1.36)
4                                                       2    (1.99)
3.5                                                    3    (2.92)
3                                                       4    (4.26)
2.5                                                    6    (6.23)
2                                                       10  (9.12)
1.5                                                    15  (13.33)
1                                                       20  (19.49)

If the observed PSA in our example was 6.86 and the biopsy revealed a
GS of 6 (3+3), then one could estimate that the patient had roughly a
(6.86-2.6)/4.26=1.0 cm^3 tumor volume.  The table very clearly
illustrates the inverse relationship between GS and PSA produced by
the tumor.

As I mentioned in my earlier post, the fact that you have a palpable
tumor suggests that you have a non-negligible tumor volume.  In
contrast, your low PSA suggests that you have a very low tumor
volume.  In an effort to better understand your situation you might
consider the following actions:
1) have your biopsy samples read by a pathologist expert in PCa.  This
will provide a confirmation of your GS.
2) There are variants of the common garden variety PCa which do not
produce much PSA and are often mis-read by a non-specialist
pathologist.  The expert pathologist would be more likely to identify
these variants, as would blood tests such as

NSE: (Neuron-Specific Enolase) is a specific marker for
neuroendocrine tumors which express proteins or enzymes that are
reflective of a de-differentiated tumor cell population such as small
cell prostate cancer.

CGA (Chromagranin A) There is a B, C, etc,. These "markers" are
products of the tumor cell population and sometimes are clues as to
the
tumor taking on an identity that is associated more with certain
clinical behavior, such as small cell prostate cancer. Such small cell
tumors grow faster, involve liver, lung and lymph nodes in unusual
sites,
frequently don't express much PSA and have lytic bone lesions instead
of
dense blastic lesions, etc. CGA is an excellent marker for
neuroendocrine tumors, particularly nonfunctioning tumors, and the
measurement of CGA is also useful to detect prostatic carcinoma in
patients whose PSA is not elevated."

3) The CDUS imaging that you are scheduling is also an excellent part
of an overall plan.  It can "see" areas that a biopsy can't sample.
It can also diagnose extra-capsular extension.

...ron