Continuing HT after RT?

Repeated studies have shown that there are significant gains in cause specific-, and overall-survival benefits associated with longer-term ADT after radiation, especially for high risk men (such as you) and especially especially for high-risk men with high Gleason scores (such as me.) This is a discussion I have had with all my doctors and the sons of guns are all sticking together. Looks like I am going the whole two years. I was hoping I could talk them down to 18 months (which would mean I was done-ish this Christmas.) But noooooo.

On the positive side, there was a study that failed to show that long-term (usually considered anything over 24 months) was better than intermediate term (12 to 18 months). Specifically, it showed that 18 months was just as good (as far as they could tell) as 36 months.

I had a chat with my radiation oncologist a few weeks ago and he said that to some extent you can trade radiation for length of HT. Since we had to start my adjuvant RT before I had recovered continence, he and my medical oncologist backed off on the radiation a smidge and lengthened my HT slightly to compensate. If I had had perfect continence going into radiation they might have gone with 70 Gray and 12 months of HT but as things were they went with 66.6 Gray and 24 months.

Thanks for the info, but I am getting the feeling that NOBODY really understands this issue. As I originally posted, I can understand (at least theoretically) a correlation between RT and concurrent HT. I do not understand why 18 months of continuing HT is better than 8 months,* but 36 months is no better than 18 months.

In my case, what would be the downside to suspending HT unless/until PSA starts rising? Isn't this essentially the same as intermittent HT? Not arguing, just trying to understand.

*Two 4 month Lupron shots. Is this how duration of HT is calculated?

And if 18 months is good, you ask, why isn't 36 months better? The reason is that the benefit as a function of duration isn't linear. It's probably some sort of sigmoid.

The curve I linked to is talking about something else but we can relabel it to address our issue.

Change...

"Population Size" to "Cancer Killing Goodness"
"Time" to "ADT Duration"
"1. Exponential Phase" to "6 Months"
"2. Transitional Phase" to "12 Months"
"3. Plateau Phase" to "18 Months"

Having done that you see a graph where the Cancer Killing Goodness starts slowly to rise as the ADT duration goes up, reaching its fastest growth at about 6 months. At that point it's about half way up -- enough cancer killing goodness for most intermediate-risk guys but not for high-risk. It keeps going up but is starting to level off at 12 months. At that point you have 90 percent of the goodness but not quite all. It rises slowly and is almost as high as its going to get by 18 months. You have to imagine 36 months way off to the right side.

sounds like you want off and you are justifying it.  radiation works long after the last treatment and radiation + HT works better.  I know HT is some miserable crap but I wouldn't let up now.  this is your shot at a cure.  your only one.

ed

 

Do any of these studies show 18 months of ADT to be better than 6 months?

http://www.ncbi.nlm.nih.gov/pubmed/22981709

I did. Could you cite a specific study? Maybe I overlooked it. Thanks.

This study: Phase III radiation therapy oncology group (RTOG) trial 86-10 of androgen deprivation adjuvant to definitive radiotherapy in locally advanced carcinoma of the prostate. concluded "In patients with Gleason score 2--6 carcinoma of the prostate, a short course of androgen ablation administered before and during radiotherapy has been associated with a highly significant improvement in local control, reduction in disease progression, and overall survival". BUT you are a gleason 7 and they also said "In patients with Gleason 7--10 tumors, the regimen has not resulted in a significant enhancement in either locoregional control or survival." Which is to say, for higher risk patients six months doesn't seem to be enough.

This study: Phase III trial of long-term adjuvant androgen deprivation after neoadjuvant hormonal cytoreduction and radiotherapy in locally advanced carcinoma of the prostate: the Radiation Therapy Oncology Group Protocol 92-02. Concluded that "The RTOG 92-02 trial supports the addition of LT adjuvant AD to STAD with RT for T2c-4 PC. In the exploratory subset analysis of patients with Gleason scores 8 to 10, LT adjuvant AD resulted in a survival advantage." Which is to say, 28 months (LT) is better than 4 (STAD). Admittedly, their short term was 4 months instead of 6 but a trend is starting to emerge.

None of these studies was designed to answer the exact question you are asking but, if you draw some reasonable inferences the answer can be inferrred.

It is, of course, up to you. The science seems to point at 18 months as the sweet spot. Less ADT seems to be less effective and more ADT doesn't seem to do much better. I am doing 24 months. I recently got my 6th of 8 three-month shots. If I stopped now it would be 18 months. Because I am a Gleason 9 with positive margins my medical oncologist prefers an excess of caution. I've discussed the duration with him -- repeatedly -- and I can't talk him down so I'm in for the whole 24.

It helps to stay active. The exercise helps with the side effects, for one thing, but just doing stuff helps. I have been greatly helped by attending the GFMPH gatherings. The guys there show newcomers that one can have a good time, even while struggling with prostate cancer -- something it is all to easy to forget...