the UpToDate medical reference site is used by docs for quick access to latest information on medical therapies-
the entry "Initial systemic therapy for castration sensitive prostate cancer" can be found here:
www.uptodate.com/contents/initial-systemic-therapy-for-castration-sensitive-prostate-cancerlong term combination of casodex/zoladex appears to provide minimal benefit while incurring greater costs and toxicity according to this article.
also, mutations in the androgen receptor binding site, where casodex blocks testosterone from bindng and helps kill the cancer cell, can occur such that the casodex then acts to stimulate AR activity causing cancer cell growth, just like testosterone- when this happens, withdrawal of casodex causes a drop in PSA
since the zoladex can drop the testosterone to castrate level (but you need a blood test to show this), the desired effect can be achieved without continuous combination with casodex. Possibly, this minimizes development of casodex-resistant cells early in the course of treatment, allowing use of casodex in a second line therapy after resistance to zoladex or lupron develop.
rf