Does anyone have a sense of how accurate the Strum model for PSA leakage is, and how to interpret discrepancies?
My situation (after RP):
A 40 cc prostate
Gleason 3+4 (25% was G4, 75% was G3)
Tumor volume 3 cc (7.5% of prostate volume)
PSA pre-op was 5.6 tested just a few days before the surgery.
According to the model, PSA should be as follows:
37 cc of health prostate tissue should generate abut 2.5 nl of PSA
2.25 cc of gleason 3 should generate about
9.6 nl of PSA
.75 cc of gleason 4 should generate about
1.5 nl of PSA
so total PSA should be about
13.6, but it was actually 5.6 (measured just a few days before the operation)
So this means either the tumor was much smaller than 3 cc (about
1 cc would make the math work) or else the tumor was much higher grade that 3+4. I doubt the former since the size of 3 cc is pretty consistent with the percentage of biopsy core length that was positive. And I doubt the latter since the biopsy was graded at two different labs (3+3) the first time and (3+4) the second time, and then the path report showed 3+4.) So that's all pretty consistent. Or it's possible that the model simply has a lot of variation from one to the next and the discrepancy doesn't really mean much.
If you want to do your own math, see www.prostate-cancer.org/education/riskases/Strum_StrategyOfSuccess2.html
and look under the heading "prostate gland volume"
Any thoughts? Thanks in advance.