Prostate Cancer Update

 The blog is not dead! and neither am I. Here are the cancer updates since before July:

1. I had surgery (Robot Assisted Laparoscopic Prostatectomy or RALP) at Mayo Clinic in Rochester MN on July 10 and carried a Foley catheter in Rochester until July 17th (oof). 

2. The surgery was successful and the unit + 2 lymph nodes were retrieved with negative margins and no lab indications of lymph node involvement (whew).

3.  The stage was Pt3a which is the same as saying stage 3.999999, ie just about poised for metastatic spread. The tumors had extended beyond the capsule and the bladder neck had been invaded. My local urologist: "looks like you dodged a bullet, my man." (whew again)

4. I have had three blood tests since July and all of them returned a PSA value of 0.03, down from 7.4. 0.03 is clinically undetectable and is equivalent to PSA = 0 + a random error term likely from the test itself (and whew yet again). 

5. The risk of cancer is currently gone (yea) with the focus now on monitoring recurrence over remaining life. This basically now becomes an exercise in information theory, signal vs noise. PSA is never zero due to either errors from the test or from tissue left behind or lurking micro-metastases.  To sift thru the noise there are standardized metrics such as threshold levels (eg 0.1 or 0.2 where 0.1 might still be noise maybe and 0.2 which probably isn't), trends where the increments are greater than x (tbd), and doubling time intervals (tbd). For now it's zero-ish so I am content with the process if not some of the unavoidable pelvic floor destruction. 

Once the prostate and surrounding tissue and implicated lymph nodes are gone the expectation is PSA = zero but there is a short period of decay from pre-surgery to 0+ε. This is pretty fast and the formula is an exponential that looks a little like a discount rate.

Here is the decay model math:

epsilon is maybe 0.02 +/- 0.01??

And this is what the model looks like in a chart for a starting 7.4:

Me? I checked my PSA at week 5, 8 and 13 just out of curiosity and to be able to walk into my first post urological in-office consult with documuentation ready and so that he doesn't have to order a test and we make another appointment. Fortunately Bozeman Health has "Labs on Demand" where I can order my own tests. I or we will continue to do this at 3 month intervals for a year or two and then every 6 months for a while and then maybe annually. 

So, Cheers.

Get your PSA checked.