This is the latest report from an ongoing research trial in the UK that involves a head-to-head comparison of ADT achieved with LHRH agonist injectable drugs versus transdermal estradiol. In this particular sub-study, there were 28 patients in the LHRH arm and 46 in the estradiol arm. After two years men, receiving transdermal estradiol maintained their bone mineral density whereas significant bone loss was seen in the men receiving an LHRH drugs for ADT.
Androgen suppression achieved with transdermal estradiol is cheaper by far than with LHRH drugs. But because estradiol is a natural hormone, which no drug company can patent, there is little industrial support for testing and marketing it for ADT.
Langley RE, Kynaston HG, Alhasso AA, Duong T, Paez EM, Jovic G, Scrase CD, Robertson A, Cafferty F, Welland A, Carpenter R, Honeyfield L, Abel RL, Stone M, Parmar MK, Abel PD. 2015. A Randomised Comparison Evaluating Changes in Bone Mineral Density in Advanced Prostate Cancer: Luteinising Hormone-releasing Hormone Agonists Versus Transdermal Oestradiol. Eur Urol [Epub ahead of print] 17 December 2015]. www.ncbi.nlm.nih.gov/pubmed/26707868