Herbal hormonal treatment for prostate cancer?

My father (80 years old) has an advanced prostate cancer with metastases with pain in leg. Zoladex
started before about 18 months (PSA dropped from 50 to 5 and stayed so for more than a year), now PSA is 50, Bicalutimide was used for about 2 months and stopped for some chest pain. Can you advise please on any herbal or non herbal treatment to improve the condition.

Herbal treatments containing phyto-oestrogens may be helpful but, in general, there are better oestrogenic compounds when we need them. Certainly, it could not be considered an optimal second-line hormonal treatment and if the Bicalutamide has outlived its usefulness the patient needs a proper consultation.