Posted 3/3/2015 9:50 PM (GMT -6)
The way I undestand it, Casodex doesn't block T, but it interferes with prostate cancer cells' abilities to bind/connect to T and use it as food to replicate (it prevents PC cells' androgen receptors from connecting to T). Thus, proponents of combined ADT would say that you should take both: Firmagon to supress your body's T production down to castrate levels, while Casodex interrupts the ability of remaining cancer cells to feed off the remaining T. In other words, even if your T levels are <20, that minuscule amount of the hormone could potentially feed any remaining PC cells that are senstive enough to connect with such low levels of T.
At least that's my understanding of why Casodex should be combined with Firmagon for the duration of HT (or, until Casodex stops working and can be withdrawn). THis is based on my dad's PC case, which is intermediary in terms of its aggressiveness, it metastasized in his lymph nodes, necessitating rather aggressive treatement.
For people with less aggressive cancers, I understand monotherapy is also just as effective (with either Casodex, or Firmagon alone). Or alternatively, for more aggressive cases, some people do a complete ADT blockade by adding Avodart as well. So the ultimate answer might also depend on the aggressiveness of your PC, and whether you subscribe to ADT2 and ADT3 theories.