As far as I can tell, it does respond to radiation, ADT and docetaxel (see below). Some oncologists may have tried other agents (like platins or growth factor inhibitors).
Metastatic ductal carcinoma of the prostate: a rare variant responding to a common treatmentYou're right that this can get very expensive. Check online for manufacturer deals on drugs. Perhaps they can hypofractionate the salvage radiation. The best deal is if you can get in on a clinical trial, but I don't see any on ductal - sometimes big tertiary care facilities like Henry Ford or UMich have some that they don't post.
- Allen