Login to Access Video or Poster Abstract: MP14-10
Sources of Funding: none

Introduction

For 30 years testosterone flare has been believed to cause rapid prostate cancer (PCa) growth, leading to disease progression, vertebral collapse with spinal cord compression, and death. Anti-androgens (AA) have been routinely offered to to prevent these risks. Given current evidence that maximal androgenic stimulation of PCa occurs at relatively low T concentrations (the saturation model), re-evaluation of the risks of T flare is indicated, as well as the need for AA treatment. _x000D_

Methods

An Ovid Medline database search was conducted to identify articles related to &[Prime]disease flare&[Prime], &[Prime]PSA flare&[Prime] or &[Prime]testosterone flare&[Prime] associated with LHRH agonists. The literature review included papers published from May 1 1980 through May 1 2016 using search terms, &[Prime]LHRH&[Prime] OR &[Prime]GNRH&[Prime] AND &[Prime]agonist&[Prime] AND &[Prime]prostate&[Prime] AND &[Prime]flare&[Prime] then &[Prime]LHRH&[Prime] was replaced with &[Prime]anti-androgen&[Prime]._x000D_

Results

Serum T rises by 40-100% during T flare, peaking at day 2-3 and returning to baseline by day 8, after which it declines to castrate levels by approximately 2-3 weeks. Few studies report PSA results or disease progression during this short interval of elevated T. Of 6 studies reporting PSA in patients given LHRH agonist alone, 5 showed no significant rise in PSA despite the presence of advanced disease and mean baseline PSAs above 500ng/ml. One reported a statistically significant increase that declined rapidly when T declined. Five RCT’s reported on disease flare in metastatic PCa patients treated with LHRH agonists +/- AA or compared with orchiectomy or DES. Three reported no disease flare in patients treated with LHRH agonists alone. One reported transient pain increase in the “LHRH alone� arm. The numbers of men reported with vertebral collapse was the same in men treated with LHRH-alone arm and in men treated with either orchiectomy or DES. Occasional reports of disease flare appear in observational studies, but these lack control arms to determine whether this merely reflects the natural history of advanced PCa. _x000D_

Conclusions

The evidence fails to support significant adverse effects associated with T flare. Most studies show no increase in PSA or disease progression during flare. Rates of vertebral collapse were identical to castration or DES. These results are consistent with the saturation model. There seems little value in adding AA to LHRH agonists, except for men with severely reduced T levels at baseline with extensive bony metastases._x000D_

Funding

none