Benefit to short-term ADT with salvage radiation

Everyone kind of thought that at least short-term ADT may be a good idea for men who needed salvage radiation after a prostatectomy. Now we know it's a good idea. You can read about the French randomized clinical trial just presented at the ASCO meeting:

Combining ADT and salvage radiation therapy improves outcomes

There are still many unanswered questions:

• Is it beneficial when radiation doses above 70 Gy are used, or with hypofractionated sRT?
Is it beneficial when started sooner?
• What are the effects of adding ADT on long-term sexual function?
• Are there subsets of patients who are more likely to benefit than others?
• Are there biochemical markers (e.g., Decipher™ or CellSearch™) that may be used to identify patients more likely to benefit?
• Should ADT be started neoadjuvantly (before sRT)? Should ADT be used concurrently and adjuvantly?
• Is the optimum duration of ADT use related to the patient’s pathological findings – pre-treatment PSA, Gleason score, stage, and positive margins?
• Would outcomes improve with the expansion of the treatment field to include pelvic lymph nodes, and in which patients?
• Would outcomes improve through the detection and boosted treatment of metastases identified using multiparametric MRIs or PET scans?
• Would immune enhancement (e.g., Provenge, Leukine, Yervoy, Keytruda) improve outcomes?
• Would outcomes improve still further with adjuvant docetaxel, as demonstrated recently by RTOG 0621?
• Would stronger forms of androgen deprivation (e.g., Zytiga or Xtandi) improve outcomes?

Lots of issues to discuss with one's radiation oncologist.

- Allen

JFL1957,

I think you should feel good about those results. The PSA of only 0.008 is well below the 0.03 threshold and doesn't seem to be in a hurry to go anywhere.

You should feel very good about the low Decipher score - do you know what it was numerically? Decipher has a negative predictive value (NPV) of 98.5% for a GC score below 0.4. That means that if your score was under 0.4, the odds that you will experience a met in the next 5 years is only 1.5% However, there is still the problem of the long natural history of progression. While a GC score under 0.4 almost certainly rules out risk of metastatic progression in the next 5 years, you don't know how safe you are in a 10- or 15-year time frame.

So you have to keep monitoring it for a few years.

My RO raised an interesting hypothesis - that guys with adverse pathology and low PSAs might benefit from just a 6-month course of ADT without radiation to kill off whatever remnants are floating around.

- Allen

This will always be a controversial subject given the side-effects of ADT....few men look forward to chemical castration... The quality of life issues can outweigh the treatment benefit..

Another factor to consider...Many R.O.'s recommend 3 years on ADT as part of their salvage radiation treatment..It seems to me, if salvage radiation fails, you may wish you still had the 3 years in the bank so to speak to use to keep your cancer in remission..If you have already burned 3 years on ADT and your PSA starts to climb, your options are much more limited..That's what happened to me and now I'm on ADT for the duration....

If he's right, some immune enhancement may help the ADT kill off the micromets. It'll be impossible to get Provenge, but insurance may go for Leukine or low-dose cyclophosphamide.