Please help! what is the best medicine for prostate cancer in stage iv?

Depends: ...On the circumstances, my friend. Hormone therapy, chemotherapy, immunotherapy, or radiation can be used. We have many new treatments to offer to use at different times. Talk to an oncologist if this is about you or a loved one.

Hormonal therapy : For stage 4 prostate cancer, hormonal therapy will be the starting treatment. Once the cancer becomes hormone resistant, typically in 2 years, other systemic treatment would be considered.