A randomised comparison evaluating changes in bone mineral density in advanced prostate cancer: luteinising hormone-releasing hormone agonists versus transdermal oestradiol

BackgroundLuteinising hormone-releasing hormone agonists (LHRHa), used as androgen deprivation therapy (ADT) in prostate cancer (PCa) management, reduce serum oestradiol as well as testosterone, causing bone mineral density (BMD) loss. Transdermal oestradiol is a potential alternative to LHRHa.ObjectiveTo compare BMD change in men receiving either LHRHa or oestradiol patches (OP).Design, setting, and participantsMen with locally advanced or metastatic PCa participating in the randomised UK Prostate Adenocarcinoma TransCutaneous Hormones (PATCH) trial (allocation ratio of 1:2 for LHRHa:OP, 2006–2011; 1:1, thereafter) were recruited into a BMD study (2006–2012). Dual-energy x-ray absorptiometry scans were performed at baseline, 1 yr, and 2 yr.InterventionsLHRHa as per local practice, OP (FemSeven 100μg/24h patches).Outcome measurements and statistical analysisThe primary outcome was 1-yr change in lumbar spine (LS) BMD from baseline compared between randomised arms using analysis of covariance.Results and limitationsA total of 74 eligible men (LHRHa 28, OP 46) participated from seven centres. Baseline clinical characteristics and 3-mo castration rates (testosterone ≤1.7 nmol/l, LHRHa 96% [26 of 27], OP 96% [43 of 45]) were similar between arms. Mean 1-yr change in LS BMD was −0.021g/cm3 for patients randomised to the LHRHa arm (mean percentage change −1.4%) and +0.069g/cm3 for the OP arm (+6.0%; p