Incidence of testosterone escape with LHRH agonists in patients receiving radiotherapy for prostate cancer.

24 Background: LHRH agonists (LHRHa) are commonly combined with radiotherapy in the neoadjuvant, concurrent, and adjuvant setting. Testosterone escape (TTE) (>1.74 nmol/L or >50 ng/dL) during therapy with LHRHa has been described, but the incidence and impact of TTE on outcome in this patient group needs to be characterized further. Methods: We performed a retrospective review of a database used for clinical outcomes and research ethics board approved studies, including chart audit of select patients (pts) where information was missing. To be included in the study, there had to be information on: 1) type of LHRHa, date of initiation, date of cessation, or duration of therapy and 2) radiotherapy information, with at least 6 months of follow-up after radiotherapy, 3) had to have radiotherapy to the prostate or prostate bed, and 4) had to have a least one testosterone- (TT) and prostatic-specific antigen (PSA) measurement. Results: 670 pts had a start date for androgen deprivation therapy (ADT) in the databa...