Is the flare phenomenon clinically significant?

Area of Science:

• Oncology
• Endocrinology

Background:

• Luteinizing hormone-releasing hormone (LHRH) analogs are standard for androgen deprivation in prostate cancer.
• These agents can cause a testosterone surge, leading to potential clinical flare.
• The frequency and severity of clinical flare, and the routine use of antiandrogens to prevent it, are debated.

Purpose of the Study:

• To review the literature on clinical flare associated with LHRH analog therapy in prostate cancer.
• To analyze the frequency and clinical manifestations of flare responses.
• To evaluate the effectiveness of antiandrogens in preventing flare responses.

Main Methods:

• Review of clinical trials involving LHRH analog therapy for prostate cancer.
• Analysis of clinical flare frequency and associated problems.
• Examination of two placebo-controlled, double-blind trials on antiandrogen efficacy.

Main Results:

• Clinical flare occurs in approximately 10% of stage D2 prostate cancer patients treated with LHRH analogs.
• Flare can manifest as bone pain, cord compression, or cardiovascular events.
• Concomitant antiandrogen therapy reduces but does not eliminate flare risk.
• Patients with D0 or neoadjuvant therapy have minimal risk of clinical flare.

Conclusions:

• Reported frequencies of clinical flare vary significantly in stage D2 disease.
• Routine antiandrogen use in the first month may be warranted for patients with symptomatic bone metastasis.
• Alternative testosterone ablation methods should be considered for patients at risk of cord compression.
• Clinical flare is rare in stage D0 disease and neoadjuvant settings.