Login to Access Video or Poster Abstract: MP53-01
Sources of Funding: none

Introduction

The predictive value of baseline serum testosterone (s-T) level in advanced prostate cancer (PCa) patients receiving androgen deprivation therapy (ADT), was studied.

Methods

PCa patients with rising prostate specific antigen (PSA) who received 1 year continuous luteinizing hormone releasing hormone (LHRH) antagonist or agonist ADT, from two large, prospective, randomized, parallel arm, phase 3 trials (NCT00295750 and NCT00928434), with 1 year follow up, were pooled for analysis, comparing low (≤250ng/dL) vs. normal (≥250ng/dL) s-T level groups, and lowest vs. highest quartiles. Kaplan-Meier (K-M) survival estimates and Cox proportional hazards regression models were used to evaluate time to PSA rise, progression-free survival (PFS), and overall survival (OS).

Results

838 men (median age 72 years) were eligible for inclusion on an intention to treat analysis basis. 138 (16.5%) had baseline s-T ≤250ng/dL, and lower s-T quartile (n=206) was [le]282ng/dL vs. ≥503ng/dL for highest quartile (n=210). s-T groups ≤250 vs. ≥250ng/dL respectively had comparable Gleason Grade 7-10 (55 vs. 58%), PSA ≥20ng/ml (38% each), locally advanced (15 vs. 24%) and metastatic stage (35 vs. 38%), with 30 vs. 32% unclassified stage at enrollment. Both analyses showed significantly worse survival end-points (p≤0.05) for low baseline s-T PCa patients, except time to PSA progression (K-M plots below), with PFS and OS hazard ratios 1.86 and 4.85 respectively.

Conclusions

According to this analysis, biochemically hypogonadal, advanced PCa patients were disadvantaged by significantly worse 1-year progression-free and overall survival after continuous LHRH based medical castration. This new evidence should prompt International guidelines to recommend incorporating baseline s-T measurement in all hormone-naïve advanced PCa patients, to identify and better inform those with low baseline s-T levels for potential inclusion into future new treatment strategy trials versus ADT.

Funding

none