Partin + Han Tables = ?Confusion?

Hi All,

I'm wondering if anyone could enlighten me on how to understand what I think are odd stats that I read on the Johns Hopkins website. I may be missing the obvious, so any thoughts would be helpful!

First, in the winter 2014 issue of their "Prostate Discovery Magazine," (article on tweaking the Gleason system) they write:
"In the past, any Gleason pattern 4 tumor was considered aggressive," says Epstein. "But we showed that Gleason score 3+4=7 cancer has a very favorable prognosis, with over 90 percent of men cured after radical prostatectomy."

Then I look at the Han Table.
Han Table for PSA 4-6; Gleason 3+4; Clinical T1c
3 years after surgery: 3% (1-10)
5 years after surgery: 5% (2-16)
7 years after surgery: 7% (2-23)
10 years after surgery:10% (3-28)

Here's the Han Table with data after surgery.
Han Table for PSA 4-6; Gleason 3+4; Organ confined
3 years after surgery: 4% (1-10)
5 years after surgery: 6% (2-17)
7 years after surgery: 9% (3-24)
10 years after surgery: 12% (4-29)

First, these numbers are pretty consistent with Epstein's quote, but I don't understand the slightly higher percentages given for after surgery if it's known to be organ confined.

Then, here's the Han table if it's not organ confined:
Han Table for PSA 4-6; Gleason 3+4; Organ confined
3 years after surgery: 12% (5-30)
5 years after surgery: 19% (7-45)
7 years after surgery: 27% (11-59)
10 years after surgery: 34% (14-68)

Finally, Partin Table for Clinical T1c; PSA 4-6; Gleason 3+4 lists the probability of organ confined to 66%.

Maybe I'm splitting hairs here, but I don't understand how people can quote a 90% cure rate for 3+4 when only 66% are predicted to be organ confined; and if it's not organ confined, then there's a 35% chance of recurrence.

Can anyone help me understand that? It seems to have pretty important implications in terms of treatment decisions....

Thanks!!

Mary

I think that the numbers work out as follows.

If you have a 66% chance of being organ confined then you have a 100-66 = 34% chance of being not organ confined. Then from those men it looks like 34% have a recurrence at 10 years or less so that would mean that your chance of being not organ confined AND having recurrence is 0.34*0.34=0.11 i.e. 11%. But you have to also add the chance that you are organ confined and have a recurrence which is 0.66*0.12=0.08 i.e. 8%. So for a man who is before surgery and so does not know if he is organ confined or not but does know that he is 3+4 his total chances of recurrence at 10 years or less is 11+8 = 19%. But if you know that you are organ confined then they are only 12%.

Another thing is that these probabilities are just averages and if you look at the numbers in parentheses they also give you the ranges so for not organ confined the chance of recurrence at ten years is anywhere between 14% and 68%, not great for sure.

Tom