George’s post helps to illustrate—as long as one looks closely—exactly how small
your concern should be, "We can do this"…and why “no treatment unless/until needed” is so highly recommended for low risk men. Let's have some fun with numbers in your specific case to understand it more fully...
George’s illustrative post starts out (2nd sentence) with “If you get a recurrence now…
” Of course, your years of post-RP PSA tests show absolutely no indication whatsoever that you would have a recurrence (biochemical recurrence, or BCR) now, or in the future…but putting that aside for a second (we will come back to that) one can use the MSKCC nomograms to examine exactly what your statistical likelihood of a BCR, which was George’s
opening “If” statement.
I plugged in your case history HERE
, and to no surprise your 10-year likelihood of BCR is about
2%. All cases similar to yours, whether they have treatment or not, have the same BCR likelihood. In other words, progression happens in some rare cases of initially low-risk men…and it happens at the same rate whether one has immediate treatment or deferred treatment.
OK, then after determining the 2% likelihood of George’s “If” statement, we can
open his link to read and understand the results a little bit more thoroughly…
George’s comment was that if the 2% probability scenario came true and you had BCR now (close to 3.5-years since RP; the study groups men into a 3.1 – 5.9 years category), and
you then did nothing to treat it further, your chances of PC-specific mortality in the next 10-years was 7.8%. These probabilities are multiplicative
, so the overall probability of someone with your case history having BCR and
also dying within 10-years (if you do nothing about
it, per George’s paper; more discussion on that in a minute) are:
2% x 7.8% = 0.15%, or a bit more than 1 in 1,000
But wait. The 7.8% probability (for men who have BCR 3.1 – 5.9 years after RP) includes ALL cases lumped together, from high- to low-risk cases. We know that makes no sense; they are really different diseases. The paper’s abstract points out the obvious by stating: “…increased pathologic Gleason score, advanced tumor stage, and rapid PSA doubling time (DT) predicted systemic progression and death from PCa,” and of course none of these apply to you. So the 7.8% death 10-years after BCR is heavily swayed by those who have completely different (advanced) cases compared to yours. The full-paper probably broke down the results by risk-category, but the abstract only summarized combined results. The 7.8% certainly grossly overstates the situation for low-risk men; for low-risk men a reasonable estimate might be closer to 1%.
But wait, there’s even more. It is absolutely reasonable given your nearly 3.5 years of clinically undetectable PSA scores, and given that your PSA doubling time is, well, zero, it seems more than reasonable to predict that IF you were to have BCR (two consecutive PSA results above 0.2 ng/mL) it wouldn’t happen until at least the paper’s next
category grouping of >5.9 years…in which case the 10-year probability of PC-specific death reduces from 7.8% to 4.7%. But, again
, this is for all
cases. A much more reasonable number for low-risk men (taking a similar % reduction as above) might be closer to 0.5%.
So, now we can use these numbers to calculate a prediction on just how unlucky you’d need to be…and how much you should really worry about
BCR and death within 10-years (if you do nothing) in your low-risk case:
2% x 0.5% = 0.01%, or about 1 in 10,000, if you do nothing post-BCR
Are you that 1 in 10,000? Maybe you should buy a lotto ticket. The risk is not zero, but maybe you should assess your diet, lifestyle & health history and determine your probability of dying of heart attack/disease.
Yes, I thought that while his
opening sentence was clear and correct ("You do not have to be afraid."), George’s post, if not more fully explained/understood, had a high likelihood of misleading readers.
As with almost everything having to do with PC, the answer to almost EVERY question is directly dependent upon your specific case characteristics, and it makes NO SENSE to blend responses from polar opposite types of cases. The ONLY thing relevant for you is similar cases. Based on the numbers discussed here, I would think most people with cases similar to "We can do this" have more significant things to worry about
than the minuscule risk of PC BCR/death.
Post Edited (NKinney) : 10/6/2017 7:54:46 AM (GMT-6)