LHRH agonists in prostate cancer: frequency of treatment, serum testosterone measurement and castrate level: consensus opinion from a roundtable discussion^*

ABSTRACT

Background: Options for lowering testosterone in patients with prostate cancer include bilateral orchiectomy, oestrogens and luteinising hormone-releasing hormone (LHRH) agonists. LHRH agonists have become widely used in the treatment of prostate cancer.

Roundtable assembly: In May 2006, a team of experts convened a roundtable assembly to discuss key issues associated with the use of LHRH agonists in the treatment of prostate cancer.

Roundtable discussion: The discussion centred on the frequency of treatment with LHRH agonists, the role of serum testosterone (ST) measurement as part of routine follow-up, and the recommended castrate level of ST. Several formulations of LHRH agonists are available, including 3-month depots that coincide with visit frequency for prostate-specific antigen (PSA) testing. Appropriate monitoring of patients receiving LHRH agonists continues to be based on PSA levels. ST determination is not recommended as part of routine follow-up, and does not provide additional prognostic benefit or improved overall management for the majority of patients. However, determination of ST may be useful in selected patients, such as those with rising PSA levels or in cases where there is doubt over LHRH agonist admin­istration or absorption. Achieving levels of ST similar to those obtained after orchiectomy is important for patient outcomes, although there is no evidence that a lower ST level (< 50 ng/dl) results in additional clinical benefits.

Conclusions: LHRH agonists should be considered first-choice testosterone-lowering therapy for the treatment of prostate cancer, with the 3-month depot formulation providing optimal convenience and flexibility. Assessment of patients receiving LHRH agonists should be based on PSA levels rather than ST levels, although levels of ST similar to those obtained after orchiectomy still need to be achieved. Further studies are warranted before the potential therapeutic benefit of considerably lowered ST levels can be fully assessed.

Key words: :

• LHRH agonists
• Prostate neoplasms
• Testosterone